[ { "id": "authors:51s5s-4tt98", "collection": "authors", "collection_id": "51s5s-4tt98", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140916-140715363", "type": "book_section", "title": "Gelcasting of Ceramic Bodies", "book_title": "Ceramics and Composites Processing Methods", "author": [ { "family_name": "Faber", "given_name": "Katherine T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Shanti", "given_name": "Noah O.", "clpid": "Shanti-N-O" } ], "contributor": [ { "family_name": "Bansal", "given_name": "Narottam P.", "clpid": "Bansal-N-P" }, { "family_name": "Boccaccini", "given_name": "Aldo R.", "clpid": "Boccaccini-A-R" } ], "abstract": "Net-shape and near-net-shape forming techniques have long been appealing in the\nproduction of ceramic materials. The high hardness and low toughness of ceramics\nmake post-densification machining both costly and time-consuming, providing strong\nincentive for the development and optimization of net-shape techniques. The oldest of\nthese forming techniques is slip casting. However, extrusion of cylindrical shapes, tape\ncasting of laminates, and gelcasting, freeze casting, and injection molding of complex\nshapes have received considerable attention. Selective laser sintering, where shapes are\ndetermined via a computer-controlled localized heating profile, and robocasting, where\nmaterial from a syringe or fine extruder is deposited in robotically controlled patterns,\nhave garnered more recent interest. Each of these techniques relies on the suspension\nof a ceramic powder in a liquid vehicle or binder system for the forming stage of the\noperation. The shaped component is solidified through drying, cooling, or gelling. Once\nresidual liquid is evaporated and binders are burned out, traditional densification\nmethods, such as sintering, are employed. \n\nTreated here is gelcasting, one of the more promising forming methods for complex-shaped\nceramic and powdered metal components. This method was patented by Janney and Omatete in the early 1990s and was explored in detail by them and their\ncoworkers at Oak Ridge National Laboratory. In their originally conceived\nmethod, a low-viscosity slurry is produced by mixing a ceramic powder into an aqueous-based\nmonomer solution, while Venkataswamy et al. used monomers that required\norganic solvents. The slurries have characteristically high solids loadings, often\ngreater than 50 vol %, but have sufficiently low viscosity to flow easily. Through the\naddition of a chemical initiator and, in some cases, a catalyst, polymerization commences,\nat which point the slurry should be cast. The chemically cross-linked network\nthat is formed through polymerization renders the ceramic powder particles immobile.\nThe filled gel conforming to the shape of the mold is rigid enough to be removed for\nfurther processing. The high water content makes a controlled drying process critical\nto prevent warping and cracking. Low binder concentrations (generally <5 wt %) can\nbe removed quickly and the body sintered. Sintering to full density is promoted by the\nhigh solids loading that can be achieved in gel-casting slurries. \n\nGelcasting should not be confused with sol-gel processing. In gelcasting, ceramic\n(or precursor) powders are suspended in a monomer or polymer solution to form slurries\nfor casting. The monomer/polymer solution gels without reacting with the suspended\npowder, in essence locking the particles in place; the same gel would form in\nthe absence of any ceramic. In sol-gel processing, ceramic precursors are integral to\nthe gel formation process (through hydrolysis, polycondensation, etc.) Metal alkoxides,\nhydroxides, and the like form the backbone of the gel network and are converted to\nceramic in later processing steps. \n\nIn this chapter, we first describe the categories of gel-casting systems and the\nchemistry of gelation in each type. Following this is a description of the processing\nsteps from gel preparation to densification. An account of the variety of structural\nclasses that are afforded by gelcasting is then presented. In addition to the processing\nof conventional bulk ceramics, gelcasting of textured ceramics, porous bodies,\nand laminates is described. Finally, gel-casting challenges and opportunities are\nhighlighted.", "doi": "10.1002/9781118176665.ch6", "isbn": "9780470553442", "publisher": "Wiley", "place_of_publication": "Hoboken, NJ", "publication_date": "2012", "pages": "199-234" }, { "id": "authors:pmcjb-88e87", "collection": "authors", "collection_id": "pmcjb-88e87", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140715-162004301", "type": "book_section", "title": "Processing, microstructure and mechanical behavior of SiC-based ceramics via naturally derived scaffolds", "book_title": "Mechanical Properties and Performance Engineering Ceramics II: Engineering and Science Proceedings", "author": [ { "family_name": "de Arellano L\u00f3pez", "given_name": "A. R.", "clpid": "de-Arellano-L\u00f3pez-A-R" }, { "family_name": "Mart\u00ednez-Fern\u00e1ndez", "given_name": "J.", "clpid": "Mart\u00ednez-Fern\u00e1ndez-J" }, { "family_name": "Varela-Feria", "given_name": "F. M.", "clpid": "Varela-Feria-F-M" }, { "family_name": "Sep\u00falveda", "given_name": "R.", "clpid": "Sep\u00falveda-R" }, { "family_name": "L\u00f3pez Robledo", "given_name": "M. J.", "clpid": "L\u00f3pez Robledo-M-J" }, { "family_name": "Llorca", "given_name": "J.", "clpid": "Llorca-J" }, { "family_name": "Pastor", "given_name": "J. Y.", "clpid": "Pastor-J-Y" }, { "family_name": "Presas", "given_name": "M.", "clpid": "Presas-M" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Kaul", "given_name": "V. S.", "clpid": "Kaul-V-S" }, { "family_name": "Pappacena", "given_name": "K. E.", "clpid": "Pappacena-K-E" }, { "family_name": "Wilkes", "given_name": "T. E.", "clpid": "Wilkes-T-E" } ], "contributor": [ { "family_name": "Tandon", "given_name": "Rajan", "clpid": "Tandon-R" }, { "family_name": "Wereszczak", "given_name": "Andrew", "clpid": "Wereszczak-A" }, { "family_name": "Lara-Curzio", "given_name": "Edgar", "clpid": "Lara-Curzio-E" } ], "abstract": "Biomorphic silicon carbide ceramics are a new class of materials fabricated by reactive infiltration of molten silicon with carbonaceus preforms obtained from wood pyrolysis. The resulting material is a Si/SiC composite, in which the SiC forms a skeleton that replicates the wood microstructure with unreacted Si filling the pores. The silicon can be removed from the composite creating a highly porous SiC material that can be refilled with other products, like metal alloys, to create ceramic/metal composites.", "doi": "10.1002/9780470291313.ch60", "isbn": "978-0-470-08052-8", "publisher": "American Ceramics Society", "place_of_publication": "Westerville, Ohio", "publication_date": "2007", "pages": "635-650" }, { "id": "authors:m2k5n-pvy31", "collection": "authors", "collection_id": "m2k5n-pvy31", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140915-104116116", "type": "book_section", "title": "A stone kneeling figure in the Art Institute of Chicago: new evidence from scientific investigations and archaeological finds in China", "book_title": "Scientific Research on the Sculptural Arts of Asia", "author": [ { "family_name": "Casadio", "given_name": "Francesca", "clpid": "Casadio-F" }, { "family_name": "Xu", "given_name": "Jay", "clpid": "Xu-J" }, { "family_name": "Pearlstein", "given_name": "Elinor", "clpid": "Pearlstein-E" }, { "family_name": "Faber", "given_name": "Katherine T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Knowles", "given_name": "Ariel", "clpid": "Knowles-A" }, { "family_name": "Zhichun", "given_name": "Jing", "clpid": "Zhichun-J" } ], "contributor": [ { "family_name": "Douglas", "given_name": "J.", "clpid": "Douglas-J" } ], "abstract": "An ancient stone sculpture of a figure kneeling with hands bound behind him was bequeathed to the Art\nInstitute of Chicago in 1950 and for many years had no known counterpart. Comparable finds are now confirmed\nby a group of similar figures discovered since 1984 at several archaeological sites in the Chengdu plain of China's\nsouthwestern Sichuan province, which are datable to the late second millennium B.C. E. Unlike those recently unearthed\nfigures, carved of more roughly textured, yellowish gray or dark green stones, some of which preserve traces of\npigment that partially highlight their facial features, the Art lnstitute's example bears a smooth and shiny blackish\ngreen surface. Questions about the nature of this surface--whether coated with a paintlike film and/or darkened by\nheating- prompted a thorough investigation of the figure. Nondestructive techniques such as in situ Raman microscopy,\nx-ray diffraction, environmental scanning electron microscopy, and near infrared reflectance spectroscopy\nwere used to fully characterize the sculpture. Fourier transform infrared spectroscopy was employed to shed light\non the nature of applied materials such as fills, surface accretions, and possible coatings. Results of these extensive\nscientific examinations, evaluated together with experimental tests of heating and polishing as well as with relevant\narchaeological evidence recently brought to light, have enhanced our understanding of the surface treatment of this\nfascinating and hitherto enigmatic sculpture.", "isbn": "1904982204", "publisher": "Archetype Press", "place_of_publication": "London", "publication_date": "2007", "pages": "3-11" }, { "id": "authors:vrgbr-8bn11", "collection": "authors", "collection_id": "vrgbr-8bn11", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210114-135221913", "type": "book_section", "title": "TMS Annual Meeting: Preface", "book_title": "Electron Microscopy, its Role in Materials Science: the Mike Meshii Symposium", "author": [ { "family_name": "Faber", "given_name": "K.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Fine", "given_name": "M.", "clpid": "Fine-M" }, { "family_name": "King", "given_name": "W.", "clpid": "King-W" }, { "family_name": "Liaw", "given_name": "P.", "clpid": "Liaw-Peter-K" }, { "family_name": "Mori", "given_name": "B.", "clpid": "Mori-B" }, { "family_name": "Weertman", "given_name": "J.", "clpid": "Weertman-Julia-R" } ], "contributor": [ { "family_name": "Weertman", "given_name": "Julia R.", "clpid": "Weertman-Julia-R" }, { "family_name": "Meshii", "given_name": "Mike", "clpid": "Meshii-Mike" } ], "abstract": "[no abstract]", "isbn": "9780873395359", "publisher": "Minerals, Metals and Materials Society", "place_of_publication": "Warrendale, PA", "publication_date": "2003-03", "pages": "ix-x" }, { "id": "authors:ynf77-85b64", "collection": "authors", "collection_id": "ynf77-85b64", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140912-170049690", "type": "book_section", "title": "Ceramics: Microstructural Toughening (Excluding Transformation Toughening, Whisker Toughening, and Continuous Fiber Toughening)", "book_title": "Encyclopedia of Materials: Science and Technology", "author": [ { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Buschow", "given_name": "K. H. J\u00fcrgen", "clpid": "Buschow-K-H-J" }, { "family_name": "Cahn", "given_name": "Robert W.", "clpid": "Cahn-R-W" }, { "family_name": "Flemings", "given_name": "Merton C.", "clpid": "Flemings-M-C" }, { "family_name": "Ilschner", "given_name": "Bernhard", "clpid": "Ilschner-B" }, { "family_name": "Kramer", "given_name": "Edward J.", "clpid": "Kramer-E-J" }, { "family_name": "Mahajan", "given_name": "Subash", "clpid": "Mahajan-S" } ], "abstract": "The enhancement of fracture toughness in ceramic materials can occur over a broad range of length scales. The length scale that has received the greatest attention in structural ceramic materials is the microstructural scale, that of the grain dimensions that normally vary from 1 \u00b5m to 20 \u00b5m. In single-phase materials, weak grain boundaries or residual stresses resulting from thermal expansion anisotropy perturb the propagation of a crack. The same is true for grain boundary phases or particulate reinforcements in multiphase materials.", "doi": "10.1016/B0-08-043152-6/00206-0", "isbn": "0-08-043152-6", "publisher": "Elsevier", "place_of_publication": "Oxford", "publication_date": "2001", "pages": "1108-1113" }, { "id": "authors:6hs2z-vj604", "collection": "authors", "collection_id": "6hs2z-vj604", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140908-181324926", "type": "book_section", "title": "Anisotropic small-angle neutron scattering studies of ceramics", "book_title": "Advanced materials for the 21st century : the 1999 Julia R. Weertman symposium", "author": [ { "family_name": "Allen", "given_name": "A. J.", "clpid": "Allen-A-J" }, { "family_name": "Fuller", "given_name": "E. R., Jr.", "clpid": "Fuller-E-R-Jr" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Zimmerman", "given_name": "M. H.", "clpid": "Zimmerman-M-H" }, { "family_name": "Wallace", "given_name": "J. S.", "clpid": "Wallace-J-S" } ], "contributor": [ { "family_name": "Chung", "given_name": "Yip-wah", "clpid": "Chung-Y-W" } ], "abstract": "This paper discusses how small-angle neutron scattering studies can be applied in two variations to obtain a representative characterization of the large, densely-populated, and anisotropic features that occur in the microstructures of various materials. The use of Pored scattering to amplify the anisotropies that are present, permitting different microstructural components to be identified, is discussed. Measurement of the anisotropic beam-broadening due to multiple small-angle neutron scattering is also described, as is its use to extract mean sizes and volume-fractions for the component microstructures. The work is illustrated by a small-angle scattering study of microcracking in a strongly textured anisotropic ceramic.", "isbn": "0873394550", "publisher": "TMS", "place_of_publication": "Warrendale, PA", "publication_date": "1999", "pages": "15-25" }, { "id": "authors:9z1ee-4ay18", "collection": "authors", "collection_id": "9z1ee-4ay18", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140908-181325031", "type": "book_section", "title": "Ceraset (TM) and Blackglas (TM) mini-tow composites with carbon-coated Nicalon (TM) tows", "book_title": "Advances in ceramic-matrix composites IV", "author": [ { "family_name": "Gonczy", "given_name": "S. T.", "clpid": "Gonczy-S-T" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "abstract": "Two commercially available preceramic polymers are the polyureasilazane Ceraset(TM) resin from DuPont Lanxide Composites and the polysiloxane Blackglas(TM) resin from AlliedSignal Inc. The Ceraset(TM) polymer pyrolyzes to a silicon carbonitride under nitrogen and a silicon carbide under argon. The Blackglas(TM) polymer produces a silicon oxycarbide under nitrogen or argon pyrolysis. Two groups of ceramic composites were made with the two preceramic polymer systems and single rows of carbon-coated ceramic grade Nicalon(TM) fiber, using 6 infiltration seeps and 1000\u00b0C argon pyrolysis. The mean tensile break loads for the two composite sets were equivalent -75 Newtons with coefficients of variation of 10-20% and obvious fiber pull-out. The break loads were independent of the matrix weight fraction, showing that the fibers are the dominant source of strength. There was no apparent difference in short term oxidation protection between the two types of matrix compositions, given the rapid oxidation of the pyrolytic carbon on the Nicalon(TM) fibers. Oxidation at 1000\u00b0C in air for one hour embrittled both sets of ceramic composites, reducing the mean break loads to 27 Newtons.", "isbn": "1574980599", "publisher": "American Ceramic Society", "place_of_publication": "Westerville, OH", "publication_date": "1999", "pages": "149-160" }, { "id": "authors:hsth4-2cm12", "collection": "authors", "collection_id": "hsth4-2cm12", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140923-163358533", "type": "book_section", "title": "Morfolog\u00eda Granular y Microestructura de Recubrimientos Cer\u00e1micos de Grano Fino Proyectados Por Plasma (Spps)", "book_title": "VI Congreso Nacional Propiedades Mec\u00e1nicas de S\u00f3lidos", "author": [ { "family_name": "de Arellano L\u00f3pez", "given_name": "A. R.", "clpid": "de-Arellano-L\u00f3pez-A-R" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Pajares Vicente", "given_name": "Anonia", "clpid": "Pajares-Vicente-A" }, { "family_name": "Cumbrera Hern\u00e1ndez", "given_name": "Francisco Luis", "clpid": "Cumbrera-Hern\u00e1ndez-F-L" }, { "family_name": "GuibertauCabanillas", "given_name": "Fernando", "clpid": "GuibertauCabanillas-F" } ], "isbn": "8484977447", "publisher": "Universidad de Extramadura", "place_of_publication": "Badajaoz, Spain", "publication_date": "1998", "pages": "234-240" }, { "id": "authors:h7xy0-9db62", "collection": "authors", "collection_id": "h7xy0-9db62", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140908-181325422", "type": "book_section", "title": "Strength and stability studies on mini-tow ceramic composites made with nitrided Nextel (TM) 312 fibers and silicon oxycarbide", "book_title": "22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A", "author": [ { "family_name": "Gonczy", "given_name": "S. T.", "clpid": "Gonczy-S-T" }, { "family_name": "Oba", "given_name": "K.", "clpid": "Oba-K" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Bray", "given_name": "Don", "clpid": "Bray-D" } ], "abstract": "Nitridation of Nextel(TM) 312 alumino-borosilicate fibers produces a boron-nitride-rich surface layer which acts as a debond layer in ceramic composites. This interface-fiber system offers a low cost alternative to CVD deposition of coatings on alumina and silicon carbide fibers. Ceramic fiber composites were made with 6 infiltration/pyrolysis cycles of a nitrided multifilament Nextel(TM) 312 mini-tow, using Blackglas(TM) resin to produce a silicon oxycarbide matrix. In the as-prepared condition the Nextel-Blackglas(TM) mini-tow composites had a mean tensile breaking load of 53 Newtons, a coefficient of variation of 26%, and limited fiber pull-out. The Nextel(TM) composites were then heat-treated in air at 600\u00b0, 800\u00b0, and 1000\u00b0C to determine oxidation stability. After 600\u00b0C oxidation for 200 hours, the Blackglas(TM) Nextel(TM) composites retained 75% of the as-prepared tensile break load with a fibrous fracture surface. Oxidation for 24 hours at 1000\u00b0C and for 100 hours at 800\u00b0C reduced the retained tensile breaking load by 47% and 66% respectively, showing reduced strain-to-failure and distinct embrittlement of the composite.", "doi": "10.1002/9780470294482.ch17", "isbn": "9780470375587", "publisher": "American Ceramic Society", "place_of_publication": "Westerville, OH", "publication_date": "1998", "pages": "147-154" }, { "id": "authors:b2nkr-b7t72", "collection": "authors", "collection_id": "b2nkr-b7t72", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140919-144228367", "type": "book_section", "title": "Comparison of Focused Ion Beam and Conventional Techniques on TEM Specimen Preparation of Metal-Ceramic Interfaces", "author": [ { "family_name": "de Arellano L\u00f3pez", "given_name": "A. Ramirez", "clpid": "de-Arellano-L\u00f3pez-A-R" }, { "family_name": "Chiou", "given_name": "W.-A.", "clpid": "Chiou-W-A" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "abstract": "The results of TEM analyses of materials are critically dependent on the quality of the sample\nprepared. Although numerous techniques have been developed in the last two decades, differential\nthinning of inhomogeneous materials remains a serious problem. Recently, focused ion beam (FIB)\ntechnique has been introduced for cross-sectional sample preparation for TEM and SEM. \nA novel system for depositing a fine-grain (~200 nm) ceramic coating on a metal surface via\na patent pending Small-Particle Plasma Spray (SPPS) technique has been developed at the Basic\nIndustry Research Laboratory of Northwestern University. To understand the properties of the\ncoated surface, the ceramic/metal interface and the microstructure of the ceramic coating must be\ninvestigated. This paper presents a comparison of the microstructure of an Al_2O_3 coating on a mild\nsteel substrate prepared using conventional and FIB techniques.", "publisher": "San Francisco Press", "publication_date": "1998" }, { "id": "authors:9rezm-9vm44", "collection": "authors", "collection_id": "9rezm-9vm44", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140912-114830027", "type": "book_section", "title": "Tensile Tests of Miniature Fiber Reinforced Ceramic Composites for Screening Process-Property Relations", "book_title": "Proceedings of the 21st Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A", "author": [ { "family_name": "Gonczy", "given_name": "S. T.", "clpid": "Gonczy-S-T" }, { "family_name": "Sprandel", "given_name": "R. C.", "clpid": "Sprandel-R-C" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Singh", "given_name": "J. P.", "clpid": "Singh-J-P" } ], "abstract": "Mechanical testing of 2-D and 3-D composites in bar geometries is material, time, and cost intensive. As an alternative low-cost, rapid-fabrication geometry, multifilament Nicalon\u2122 (with pyrolytic carbon-coating) tows were densified with the preceramic polymer (Blackglas\u2122) technology to form single tow ceramic \"mini-composites\". Using modified ASTM tow testing methods, the Blackglas-Nicalon(C) mini-composites were tested in tension at ambient temperatures. The ceramic mini-composites had fibrous failure with linear load-deflection curves and mean breaking loads of 70 N. Gage length (1, 2.5 & 5 cm) effects on breaking loads were minimal. The coefficient of variation (CoV) for the ceramic mini-composites was 19% as compared to a 10% CoV for earlier tensile tests on Blackglas-Nicalon 2-D fabric composite bars. Results were compared to tensile tests of epoxy-Nicalon tows. Breaking strengths of the ceramic mini-composites were roughly 30% of the breaking strengths of the epoxy-Nicalon composites. Oxidation at 600\u00b0 and 1000\u00b0C for 1 hour embrittled the Blackglas-Nicalon (C) composites and reduced the breaking load to values of 42 N and 17 N, respectively.", "doi": "10.1002/9780470294437.ch79", "isbn": "9780470375495", "publisher": "Wiley", "place_of_publication": "Hoboken, NJ", "publication_date": "1997", "pages": "729-736" }, { "id": "authors:0jyg3-xqt19", "collection": "authors", "collection_id": "0jyg3-xqt19", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140908-181328107", "type": "book_section", "title": "Crack stability in the fracture of cementitious materials", "book_title": "Microstructure of Cement-Based Systems/Bonding and Interfaces in Cementitious Materials", "author": [ { "family_name": "Tandon", "given_name": "S.", "clpid": "Tandon-S" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Bazant", "given_name": "Z. P.", "clpid": "Ba\u017eant-Z-P" } ], "contributor": [ { "family_name": "Diamond", "given_name": "S.", "clpid": "Diamond-S" }, { "family_name": "Glasser", "given_name": "F. P.", "clpid": "Glasser-F-P" }, { "family_name": "Mindess", "given_name": "S.", "clpid": "Mindess-S" }, { "family_name": "Roberts", "given_name": "L. R.", "clpid": "Roberts-L-R" }, { "family_name": "Skalny", "given_name": "J. P.", "clpid": "Skalny-J-P" } ], "abstract": "The aim of the present study is to investigate the stability of crack propagation in cementitious materials. Tests were conducted on bend specimens in three-point and four-point loading conditions. Three-point bend specimens showed stable crack growth for mortar, normal strength and high strength concrete specimens. Alternatively, four-point bend specimens showed catastrophic failure for mortar and quasi-catastrophic failure for normal strength and high strength concrete specimens. Results will be discussed in relation to brittleness number model and specific microstructural features including the interfacial transition zone between the cement paste and the aggregate and the attendant toughening mechanisms.", "doi": "10.1557/PROC-370-387", "isbn": "1558992723", "publisher": "Materials Research Society", "place_of_publication": "Pittsburgh, PA", "publication_date": "1995", "pages": "387-396" }, { "id": "authors:1fmz7-x1097", "collection": "authors", "collection_id": "1fmz7-x1097", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140908-181328464", "type": "book_section", "title": "Effects of Reinforcement Surface Morphology on Toughening of Brittle-Matrix Composites", "book_title": "High Performance Composites: Commonalty of Phenomena", "author": [ { "family_name": "Mumm", "given_name": "Daniel R.", "clpid": "Mumm-D-R" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Chawla", "given_name": "K. K.", "clpid": "Chawla-K-K" }, { "family_name": "Liaw", "given_name": "P. K.", "clpid": "Liaw-P-K" }, { "family_name": "Fishman", "given_name": "Steven G.", "clpid": "Fishman-S-G" } ], "abstract": "The mechanical properties of brittle-matrix composites critically depend upon the nature of the\nreinforcement/matrix interface. Recent theoretical and experimental work has shown that the\nmorphology of the reinforcement surface can play a dominant role in determining the toughening\nbehavior in these materials. In this work, the role of reinforcement surface roughness is\nexamined both analytically and experimentally. Measurements of the debonding and frictional\nsliding of rough fibers in glass matrices, obtained using a modified fiber pullout technique, show\na significant dependence on fiber surface roughness. The effects of surface roughness are\nexplored further by measuring systematic changes in the fiber sliding behavior with controlled\nfiber coatings. The available analytical models of rough fiber sliding are examined to interpret\nthe experimental results.", "isbn": "0873392477", "publisher": "Minerals, Metals & Materials Society", "place_of_publication": "Warrendale, PA", "publication_date": "1994-10", "pages": "181-192" }, { "id": "authors:6cxbk-rqh74", "collection": "authors", "collection_id": "6cxbk-rqh74", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140908-181328349", "type": "book_section", "title": "Interface Design in Brittle-Brittle Systems", "book_title": "High Performance Composites: Commonalty of Phenomena", "author": [ { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Mumm", "given_name": "Daniel R.", "clpid": "Mumm-D-R" } ], "contributor": [ { "family_name": "Chawla", "given_name": "K. K.", "clpid": "Chawla-K-K" }, { "family_name": "Liaw", "given_name": "P. K.", "clpid": "Liaw-P-K" }, { "family_name": "Fishman", "given_name": "Steven G.", "clpid": "Fishman-S-G" } ], "abstract": "In brittle matrix composites both ceramic, intermetallic, and cement-based, design of the fiber-matrix\ninterface is key to achieving high composite toughness. In this paper we explore first, a\nmethod for accurately determining interfacial properties and second, the influence of physical\nand chemical aspects of the fiber-matrix interface which influence fracture toughness of the\ncomposite. \n\nA modified fiber pullout technique has been developed which allows direct experimental\nevaluation of the force-displacement relation for a crack bridging fiber. The technique allows\ncontinuous, accurate measurement of stable, progressive debonding and frictional sliding. \n\nCoupled with an appropriate analysis, the test provides a quantitative determination of\ninterfacial properties relevant to the toughening of brittle materials.\nAmong the parameters of influence in determining interfacial properties, and consequently,\ncomposite toughness, are interface toughness, surface roughness, residual stress state, and\ncoefficient of friction. Each of these can be altered by use of coatings or surface modifications.\nExamples of each will be reviewed in a variety of brittle systems.", "isbn": "0873392477", "publisher": "Minerals, Metals & Materials Society", "place_of_publication": "Warrendale, PA", "publication_date": "1994-10", "pages": "131-142" }, { "id": "authors:an0g1-nj648", "collection": "authors", "collection_id": "an0g1-nj648", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140915-112949042", "type": "book_section", "title": "Multiple Cracking and Interface Debonding in a Brittle Film on a Ductile Rod", "book_title": "Advances in Ceramic-Matrix Composites", "author": [ { "family_name": "Cazzato", "given_name": "A.", "clpid": "Cazzato-A" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Bansal", "given_name": "N. P." } ], "abstract": "A test technique was developed to measure interfacial shear strength through\nobservation of crack densities in bimaterial concentric cylinders. Multiple cracking\nand debonding were observed in a model ductile-brittle pair of aluminum rods\nwith soda-silicate cement coatings and the results compared to a system where the\ninterface was modified by a polymeric interphase layer. A shear lag analysis was\nused to relate the observed crack densities to the interfacial shear strength. Four\npoint bend tests were performed on monolithic soda-silicate cement specimens to\ndetermine the statistical variation in strength of the coating material. A multiple\ncracking computer simulation was developed to include the statistical nature of the\ncoating strength. The crack density, bend testing and simulation results were integrated\nto calculate interfacial shear strength in the Al-cement system.", "isbn": "0944904696", "publisher": "American Ceramic Society", "place_of_publication": "Westerville, OH", "publication_date": "1993", "pages": "329-338" }, { "id": "authors:1qjkd-x1b91", "collection": "authors", "collection_id": "1qjkd-x1b91", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140919-144538556", "type": "book_section", "title": "Fracture of Brittle and Quasi-Brittle Engineering Materials", "author": [ { "family_name": "Tandon", "given_name": "S.", "clpid": "Tandon-S" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "abstract": "The study of fracture of engineering materials involves a number of science and engineering\ndisciplines. Continuum fracture mechanics is deeply rooted in the problem of fracture\nbecause it treats the relationship between a crack or inhomogeneity and the stress\nstate in a material. Physics and chemistry are important because they help to explain the\nreactions between the environment and the crack tip. Finally, materials science is essential\nin understanding the relations among bond rupture, structure, processing and performance\nof a material.\nFracture of materials can be divided into two broad categories - ductile and brittle\nfracture. Ductile fracture is associated with appreciable plastic deformation. \"Cup and\ncone\" fracture demonstrated in metals due to tensile overload is a classic example of ductile\nfracture. The different stages of such fracture are shown in Figure l.l(a). At the maximum\nload, plastic deformation is concentrated in a small gage length of the specimen and\nnecking begins. Once this necked region has formed, fracture begins at the center of the\nspecimen and extends along the dashed lines, finally producing the familiar cup and cone\nfracture. In fcc metals, plastic deformation continues on the conjugate slip planes until the\nspecimen has necked down to a sharp point. Polycrystalline metals with second phase particles\nfail due to initiation, growth and coalescence of micro-voids formed in the necked region. Similarly, semicrystalline polymers exhibit necking which leads to localized\nstrengthening of the specimen. Then the specimen elongates due to the propagation of this\nneck along the gage length. This ductile fracture in polymers is different from that in metals,\nin which all subsequent deformation is confined to the neck region.\nAlternatively, brittle fracture is associated with little or no deformation. A brittle material\nbehaves elastically up to the maximum load at which catastrophic failure occurs (Fig.\n1.1(b )). Silicate glasses are the most common example of such fracture. Brittle fracture\nis controlled by microscopic inclusions, surface and interior flaws and defects and pores\npresent in the material. An intermediate category of fracture, known as quasi-brittle\nfracture, has recently been defined. A quasi-brittle material, a title which encompasses\nmany polycrystalline ceramics and cementitious materials, shows measurable deformation\nprior to failure. The deformation, however, is not associated with dislocation motion. At\nthe onset of nonlinearity in the load-displacement relationship existing flaws in the material\nstart growing and new flaws form (Fig. 1.1(c)). Such materials are characterized by a\nsoftening curve after the peak load. This softening branch of the load-displacement relationship\nis associated with stable crack growth in the material before the final fracture. The\nfailed specimen, however, need not look any different from a classically-brittle failed specimen. \n\nIn a review article such as this, it is useful to first build the necessary background, and\nvarious aspects of fracture mechanics are reviewed in the next section. This review is followed\nby discussions of the microstructural aspects of toughening mechanisms, short crack\nfracture in comparison to long crack fracture, the statistical nature of fracture and its implications\nfor quasi-brittle materials, and slow crack growth and other environmental effects\non various fracture processes are presented. The implications to cementitious materials\nare discussed throughout.", "publisher": "American Ceramic Society", "publication_date": "1993" }, { "id": "authors:jtfxv-g4v64", "collection": "authors", "collection_id": "jtfxv-g4v64", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140915-113613432", "type": "book_section", "title": "DCB Methods for Examining Toughening in Alumina Reinforced with Carbon Coated SiC Whiskers", "book_title": "Advances in Ceramic-Matrix Composites", "author": [ { "family_name": "Steyer", "given_name": "T. E.", "clpid": "Steyer-T-E" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Bansal", "given_name": "N. P." } ], "abstract": "The mechanical properties of Al_2O_3 have been substantially improved by the addition\nof SiC whiskers. Room temperature strength and fracture toughness have\nbeen reported for a variety of whisker sources and whisker fractions. The composite\nmicrostructure and the properties of the whisker/matrix interface allow various\ntoughening mechanisms to be active in the SiC/Al_2O_3 system including crack\nbranching and deflection, whisker and grain bridging, and whisker debonding and\npullout.\n\nModifications of the whisker/matrix interface are one way of tailoring the composite\nmicrostructure. Tiegs et al. have made composites from heat-treated and acid-leached\nwhiskers to modify the whisker surface chemistry and the whisker/matrix\ninterfacial chemistry. \n\nA second means of modifying the whisker/matrix interface has been suggested by\nHsueh et al. in which a low modulus film is used to modify the residual stress.\nUsing this theory, a 50 \u00c5 carbon film on a 0.7 \u03bcm diameter whisker would result in\na nearly ten percent reduction of residual stress at the whisker/matrix interface in\nSiC whisker-reinforced alumina. \n\nSiC whiskers coated with carbon are used in this study as a way of modifying the\nchemical and mechanical bonding at the whisker/matrix interface by directly\nchanging the interfacial chemistry and by modifying the residual thermal stresses found in these materials due to the thermal expansion mismatch of the composite\nconstituents. In this study, two DCB methods of analysis are used to examine the\neffects of modified interfaces on fracture toughness in these materials.", "isbn": "0944904696", "publisher": "American Ceramic Society", "place_of_publication": "Westerville, OH", "publication_date": "1993", "pages": "617-630" }, { "id": "authors:5gpmg-q8r84", "collection": "authors", "collection_id": "5gpmg-q8r84", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140915-111614317", "type": "book_section", "title": "Micro-Mechanical Aspects of Fiber Debonding and Frictional Sliding in Brittle Matrix Composites", "book_title": "Advances in Ceramic-Matrix Composites", "author": [ { "family_name": "Mumm", "given_name": "Daniel R.", "clpid": "Mumm-D-R" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Bansal", "given_name": "N. P.", "clpid": "Bansal-N-P" } ], "abstract": "It is now well established that the mechanical behavior of a fiber-reinforced brittle-matrix material largely depends on the properties of the fiber-matrix interface. In\nparticular, to obtain enhanced toughness through fiber reinforcement, the interface\nmust exhibit a relatively low fracture energy such that fiber debonding and crack\nbridging occur during matrix crack propagation. With further matrix crack extension,\ndebond propagation and frictional fiber sliding occur, providing energy dissipation\nfor enhanced toughness. Interfacial properties of importance include the\nfracture energy, frictional sliding characteristics and residual stress state. In addition,\nthe morphology of the sliding interface has recently emerged as an important\ninterfacial parameter which can greatly influence fiber debonding and sliding\nbehavior. Experimental evidence of the role of fiber surface morphology during\nfiber sliding was first reported by Jero and Kerans. \n\nRecognition of the importance of the interfacial properties has prompted the development\nof a number of techniques to evaluate these parameters, including the single-fiber pull-out and push-down tests. These techniques are designed to directly\ndetermine composite interfacial properties, and therefore, assess the mechanical\nperformance of fiber-reinforced brittle-matrix materials. Numerous fiber debonding\nand sliding experiments have been done using these two techniques. However,\na number of factors make it difficult to determine fundamental interfacial\nproperties from such tests. For instance, with the push-down technique, the sample\ngeometry results in prominent end effects. In addition, the preparation of pushdown\nspecimens may allow relief of residual stresses which are now known to play an important role in determining fiber debonding and sliding behavior. Furthermore,\nsince the applied loads are compressive, the push-down technique does\nnot properly evaluate the effects of locally sliding fiber strength, i.e. fiber fracture\naway from the matrix crack plane and the frictional pull-out of the fractured fibers. \n\nThere are equivalent concerns with the standard single-fiber pull-out technique.\nThe free length of fiber protruding from the edge of the specimen leads to low system\nstiffness, and accurate fiber displacement measurements are difficult to obtain.\nIn this work, an improved single-fiber pull-out technique .has been developed and\nused to observe stable, progressive fiber debonding and sliding in two model composite\nsystems. Fiber surface roughness is shown. to have a pronounced effect on\nthe interfacial frictional sliding in these composite systems. Roughness-induced\nload fluctuations are observer during progressive debonding, with the fluctuation\namplitude increasing with frictional sliding zone length.", "isbn": "0944904696", "publisher": "American Ceramic Society", "place_of_publication": "Westerville, OH", "publication_date": "1993", "pages": "163-172" }, { "id": "authors:rf8j9-0bv30", "collection": "authors", "collection_id": "rf8j9-0bv30", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140916-205922710", "type": "book_section", "title": "Fiber Debonding and Pullout Processes in Ceramic Composites", "book_title": "Proceedings of the 16th Annual Conference on Composites and Advanced Ceramic Materials", "author": [ { "family_name": "Mumm", "given_name": "D. R.", "clpid": "Mumm-D-R" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Wachtman", "given_name": "John B., Jr.", "clpid": "Wachtman-J-B-Jr" } ], "abstract": "The fiber debonding and pullout behavior in a model ceramic composite system has been investigated using a novel single-fiber pullout technique. Stable, progressive debonding was observed prior to fiber fracture and frictional fiber pullout. Interfacial parameters were calculated from single load-displacement curves using a recent analysis of the fiber debonding and pullout process. The interfacial parameters extracted from these experiments are consistent with independent measurements reported in the literature. The morphology of the fiber surface appears to play a significant role in determining the fiber debonding and sliding behavior.", "doi": "10.1002/9780470313954.ch8", "isbn": "9780470375174", "publisher": "American Ceramic Society", "place_of_publication": "Westerville, OH", "publication_date": "1992", "pages": "70-77" }, { "id": "authors:4c78e-xx556", "collection": "authors", "collection_id": "4c78e-xx556", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140916-204747280", "type": "book_section", "title": "Fracture Behavior of SiC Whisker-Reinforced Al_2O_3 with Modified Interfaces", "book_title": "Proceedings of the 16th Annual Conference on Composites and Advanced Ceramic Materials", "author": [ { "family_name": "Steyer", "given_name": "T. E.", "clpid": "Steyer-T-E" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Wachtman", "given_name": "John B., Jr.", "clpid": "Wachtman-J-B-Jr" } ], "abstract": "Carbon-coated SiC whiskers have been examined as a function of coating thickness for reinforcement in Al_2O_3. A compliant carbon layer at the whisker/ matrix interface modifies the residual stress due to thermal expansion mismatch and changes the interfacial chemistry. The fracture behavior of this material has been observed using 4-point bending for strength and the double cantilever beam technique for fracture toughness and R-curve behavior. The strength and R-curve behavior of composites with and without whisker coatings of carbon are presented to evaluate the effect of modified interfaces on the mechanical performance of whisker composites.", "doi": "10.1002/9780470313978.ch11", "isbn": "9780470375198", "publisher": "American Ceramic Society", "place_of_publication": "Westerville, OH", "publication_date": "1992", "pages": "669-677" }, { "id": "authors:3v5nb-avf12", "collection": "authors", "collection_id": "3v5nb-avf12", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210114-140129140", "type": "book_section", "title": "Preface", "book_title": "Semiconductors and Semimetals", "author": [ { "family_name": "Faber", "given_name": "Katherine T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Malloy", "given_name": "Kevin J.", "clpid": "Malloy-Kevin-J" } ], "contributor": [ { "family_name": "Faber", "given_name": "Katherine T.", "clpid": "Faber-K-T" }, { "family_name": "Malloy", "given_name": "Kevin J.", "clpid": "Malloy-Kevin-J" } ], "abstract": "[no abstract]", "doi": "10.1016/s0080-8784(08)62511-9", "isbn": "9780127521374", "publisher": "Academic Press", "place_of_publication": "San Diego, CA", "publication_date": "1992", "pages": "ix-x" }, { "id": "authors:bj5te-2ff98", "collection": "authors", "collection_id": "bj5te-2ff98", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140908-181329407", "type": "book_section", "title": "Mechanical Behavior of Compound Semiconductors", "book_title": "Mechanical Properties of Semiconductors", "author": [ { "family_name": "Guruswamy", "given_name": "Sivaraman", "clpid": "Guruswamy-S" }, { "family_name": "Faber", "given_name": "Katherine T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Hirth", "given_name": "John P.", "clpid": "Hirth-J-P" } ], "contributor": [ { "family_name": "Faber", "given_name": "Katherine T.", "clpid": "Faber-K-T" }, { "family_name": "Malloy", "given_name": "Kevin J.", "clpid": "Malloy-K-J" } ], "abstract": "The semiconductor industry has long been aware of the need to avoid\ndeformation during bulk single-crystal semiconductor growth or during\nsubsequent device processing. The generation of dislocations during liquid-encapsulated\nCzochralski (LEC) growth of Si, Ge, GaAs, and other III-V\ncompounds is believed to occur when the thermal stress imposed on the\ncrystal during growth exceeds the critical resolved shear stress (CRSS) and\nthe crystal is deformed (Mil'vidskii and Bochkavev, 1978; Jordan et al., 1980,\n1984, and 1986). The dislocation density increase that results from deformation\nhas a deleterious effect on the device yield, performance and reliability\n(Nanishi et al., 1982; Petroff and Hartman, 1973; Miyazawa and Hyuga,\n1986). The reduction of thermal stresses during crystal growth and enhancement\nof crystal strength by doping, such as with In and Si in GaAs (Jordan\nand Parsey, 1986, 1988; McGuigan et al., 1986) makes possible growth of\nlarge single crystals with reduced defects. The deformation behavior of Si and\nGe has been a subject of much research for the past three decades while\nlimited studies have been performed on III-V and II-VI compound semiconductors\nsuch as GaAs, InP, and CdTe. The mechanical response of these\ncrystals depends on the crystal structure, nature of atomic bonding, concentration\nof dopants, temperature, and strain or loading rate. In this paper we\nreview the current understanding of the deformation behavior in these\nmaterials. Their expected behavior at low, intermediate, and high temperatures,\npredicted from the current understanding of dislocation motion in\nsolids, is presented along with compressive, tensile, and hardness data on\nGaAs, InP, CdTe, and Si. The effects of ternary dopants on the mechanical\nbehavior of these materials are analyzed using ideas of solid solution\nstrengthening and defect chemistry. Finally, implications for defect-free\ncrystal growth and device fabrication are examined.", "doi": "10.1016/S0080-8784(08)62516-8", "isbn": "0-12-752137-2", "publisher": "Academic Press", "place_of_publication": "Boston, MA", "publication_date": "1992", "pages": "189-230" }, { "id": "authors:z3wxb-jcy10", "collection": "authors", "collection_id": "z3wxb-jcy10", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140908-181329775", "type": "book_section", "title": "Fracture Properties on SiC Based Particulate Composites", "book_title": "Toughening Mechanisms in Quasi-Brittle Materials", "author": [ { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Gu", "given_name": "W.-H.", "clpid": "Gu-W-H" }, { "family_name": "Cai", "given_name": "H.", "clpid": "Cai-H" }, { "family_name": "Winholtz", "given_name": "R. A.", "clpid": "Winholtz-R-A" }, { "family_name": "Magley", "given_name": "D. J.", "clpid": "Magley-D-J" } ], "contributor": [ { "family_name": "Shah", "given_name": "S. P.", "clpid": "Shah-S-P" } ], "abstract": "In order to evaluate the role of residual stresses in\nfracture toughening, a SiC-based particulate composite has been studied\nunder uniform stressing conditions and in the near tip stress field of a\npre-cracked specimen. First, residual stresses in a SiC-TiB_2 composite\nbefore and after stressing have been measured using x-ray diffraction.\nTensile residual stresses in the TiB_2 drop by 50% after bending stresses\nof 250 MPa were applied. Likewise, the compressive residual stresses in\nthe SiC phase decrease accordingly. Second, in the near tip stress\nfield, a process zone of microcracks has been measured using\ntransmission electron microscopy of thin foils taken from various\nlocations from a fracture surface of a fracture mechanics specimen.\nMicrocrack zones greater than 150 \u03bcm in height have been measured.\nCrack bridging sites of TiB_2 particles operate more than a few\nmillimeters behind a propagating crack. Hence, the toughening in this\nsystem is comprised of both stress-induced microcracking and crack\nbridging. The various contributions to the toughening are discussed.", "doi": "10.1007/978-94-011-3388-3_1", "isbn": "0792311981", "publisher": "Kluwer Academic Publishers", "place_of_publication": "Boston, MA", "publication_date": "1991", "pages": "3-17" }, { "id": "authors:67wa6-5rz06", "collection": "authors", "collection_id": "67wa6-5rz06", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140917-175220552", "type": "book_section", "title": "Microcrack Toughening in a SiC-TiB_2 Composite", "book_title": "Proceedings of the American Society for Composites Fifth Technical Conference : composite materials in transition", "author": [ { "family_name": "Cai", "given_name": "H.", "clpid": "Cai-H" }, { "family_name": "Gu", "given_name": "W.-H.", "clpid": "Gu-W-H" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "abstract": "Transmission electron microscopy observations of a fractured SiC-TiB_2\ncomposite have provided conclusive evidence of stress-induced microcracking\nin this system. The microcrack density parameter around a steadily growing\ncrack has been measured as a function of the distance from the crack plane.\nMicrocrack toughening in this system has been assessed using a discrete\nmodel based on the measured microcrack density parameter. The\ncomputation results indicate that nearly half of the toughening arises from\nstress-induced microcracking. Other possible toughening mechanisms are\nalso discussed.", "isbn": "0877627673", "publisher": "Technomic Publishing", "place_of_publication": "Lancaster, PA", "publication_date": "1990", "pages": "892-901" }, { "id": "authors:6efb9-vhv88", "collection": "authors", "collection_id": "6efb9-vhv88", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140916-201611322", "type": "book_section", "title": "Interfacial Shear Stresses in SiC and Al_2O_3 Fiber-Reinforced Glasses", "book_title": "Proceedings of the 12th Annual Conference on Composites and Advanced Ceramic Materials", "author": [ { "family_name": "Goettler", "given_name": "R. W.", "clpid": "Goettler-R-W" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Wachtman", "given_name": "John B., Jr.", "clpid": "Wachtman-J-B-Jr" } ], "abstract": "Single fiber pullout tests were performed on silicon carbide and sapphire filaments embedded in glass matrices to determine the interfacial shear strengths both as a function of residual stress and as a function of fiber coating. The effect of residual stress on the interfacial shear stress was studied by altering the glass matrix composition, and hence, the thermal mismatch between fiber and matrix. The interfacial shear strength exhibits a maximum with increasing thermal mismatch after which it drops precipitously and levels off. The presence of a carbon coating on sapphire is sufficient to reduce the interfacial shear stress to measurable levels, while excess carbon at the SiC/glass interface increases the interfacial shear stress. In the silicon carbide-reinforced systems, the interfacial shear strengths are also shown to be stressing-rate dependent.", "doi": "10.1002/9780470310496.ch37", "isbn": "9780470374801", "publisher": "American Ceramic Society", "place_of_publication": "Westerville, OH", "publication_date": "1988", "pages": "861-870" }, { "id": "authors:fm918-yxs92", "collection": "authors", "collection_id": "fm918-yxs92", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140916-142040172", "type": "book_section", "title": "Toughening in ZrO_2-Based Materials", "book_title": "Advanced Ceramics", "author": [ { "family_name": "Faber", "given_name": "Katherine T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Saito", "given_name": "Shinroku", "clpid": "Saito-S" } ], "abstract": "Fracture toughening processes in transformation toughened zirconia and related\nsystems are reviewed. The main toughening derives from the martensitic transformation of\ntetragonal ZrO_2 particles to their monoclinic form ahead of a crack as analyzed by\nthermodynamic and continuum approaches. The implications for crack-length dependent\nfracture resistance based upon the toughening models are included. Additional toughening\ncontributions are evaluated for microcracking and crack deflection processes using recent\nmodels. Systems where transformation toughening occurs are summerized, including\nmaterials which are surface-strengthened through the tetragonal-monoclinic transformation.\nThe effects of temperature and environment on mechanical behavior are also\nconsidered.", "isbn": "0198563353", "publisher": "Oxford University Press", "place_of_publication": "New York, NY", "publication_date": "1988", "pages": "76-94" }, { "id": "authors:k2nez-9d339", "collection": "authors", "collection_id": "k2nez-9d339", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140916-121838056", "type": "book_section", "title": "Segregant enhanced fracture of mechanics", "book_title": "Interfacial structure, properties, and design : symposium held April 5-8, 1988, Reno, Nevada, U.S.A.", "author": [ { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Hickenbottom", "given_name": "Cynthia C.", "clpid": "Hickenbottom-C-C" } ], "contributor": [ { "family_name": "Yoo", "given_name": "M. H.", "clpid": "Yoo-M-H" }, { "family_name": "Clark", "given_name": "W. A. T.", "clpid": "Clark-W-A-T" }, { "family_name": "Briant", "given_name": "C. L.", "clpid": "Briant-C-L" } ], "abstract": "The fracture toughness and failure mode of ceramic materials are highly\nsensitive to the presence of impurities at grain boundaries. Magnesium\noxide serves as a model material to investigate fracture with respect to\nimpurity levels at grain boundaries. Lithium fluoride, added to MgO as a\nsintering aid, is retained as an intergranular phase. By post-fabrication\nheat treatment, the LiF is removed and a change in fracture mode follows.\nTransmission and scanning electron microscopy, along with analytical (atomic\nabsorption spectroscopy and selective electrode analysis) and microanalytical\n(scanning Auger microprobe) techniques are used to follow the progression of LiF with heat treatment. The results of this study are compared\nto other oxides and carbide systems in which the fracture toughness has also\nbeen found to be sensitive to the amount and location of segregants.", "isbn": "0931837928", "publisher": "Materials Research Society", "publication_date": "1988", "pages": "475-483" }, { "id": "authors:3hevj-1p593", "collection": "authors", "collection_id": "3hevj-1p593", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140916-125902002", "type": "book_section", "title": "Temperature-Dependent Toughening in Whisker-Reinforced Ceramics", "book_title": "Ceramic Microstructures '86: Role of Interfaces", "author": [ { "family_name": "Shaw", "given_name": "M. C.", "clpid": "Shaw-M-C" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Pask", "given_name": "Joseph A.", "clpid": "Pask-J-A" }, { "family_name": "Evans", "given_name": "Anthony G.", "clpid": "Evans-A-G" } ], "abstract": "The mechanical response of whisker-reinforced ceramics, which is dominated by interfacial chemistry-arid stress, is expected to vary as thermal mismatch stresses diminish and grain boundary phases soften with increasing temperature. To examine the temperature dependence of the toughening process two silicon carbide whisker-reinforced systems have been studied: alumina and mullite. The systems represent a range of thermal mismatch conditions and potential crack-whisker interactions including crack bridging, whisker pull-out and crack deflection. For both systems, fracture toughness and hardness are measured as a function of temperature. The fracture toughness of both materials shows little change to 1100\u00b0C. However, post-mortem fractography indicates that limited pullout occurs in the mullite/SiC_w system at elevated temperatures. Only whiskers oriented normal to the fracture plane are pulled out without fracture due to the additional bending stresses on the whiskers. In the alumina/SiC_w system, the mode of fracture remains invariant with temperature because of high whisker compressive stresses. These observations indicate that for randomly-oriented whiskers substantial toughening by pull-out is contingent upon low interfacial stresses coupled with high strength whiskers which can sustain large bending stresses.", "doi": "10.1007/978-1-4613-1933-7_92", "isbn": "978-1-4612-9074-2", "publisher": "Plenum Press", "place_of_publication": "New York, NY", "publication_date": "1987", "pages": "929-938" }, { "id": "authors:pv0pz-1x848", "collection": "authors", "collection_id": "pv0pz-1x848", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140915-114401795", "type": "book_section", "title": "TEM Studies of Dislocations in Deformed Ga_(x)In_(1-x)As Single Crystals", "author": [ { "family_name": "Rai", "given_name": "R. S.", "clpid": "Rai-R-S" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Guruswamy", "given_name": "S.", "clpid": "Guruswamy-S" }, { "family_name": "Hirth", "given_name": "J. P.", "clpid": "Hirth-J-P" } ], "contributor": [ { "family_name": "Bailey", "given_name": "G. W.", "clpid": "Bailey-G-W" } ], "abstract": "The control of dislocation density during the growth of GaAs and related\ncompounds is highly desirable for obtaining improved performance and\nreliability of opto-electronic devices. Doping of single crystal GaAs grown\nby the LEC process with Indium has been known to reduce the dislocation\ndensity significantly. Substitutional solid-solution strengthening of GaAs\nas an InAs unit been suggested to be responsible for reduction of\ndislocation density. To understand the mechanism involved in dislocation\ndensity reduction deformation tests have been performed on [001] oriented\nGa_XIn_(1-x)As single crystals in the temperature range 700-1100\u00b0C and this\npaper reports some results of the TEM characterization of dislocations in\nthese deformed single crystals.", "publisher": "San Francisco Press", "publication_date": "1987" }, { "id": "authors:384rk-gxf34", "collection": "authors", "collection_id": "384rk-gxf34", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140918-144111634", "type": "book_section", "title": "Low Thermal Expansion Coatings for Carbon/Carbon Composites", "author": [ { "family_name": "Kerans", "given_name": "R. J.", "clpid": "Kerans-R-J" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Buckley", "given_name": "John D.", "clpid": "Buckley-J-D" } ], "abstract": "Two classes of materials are considered for low expansion protective\ncoatings for carbon/carbon composites. They include composites containing\nparticles which undergo allotropic phase transformations accompanied by\nnegative volume changes with increasing temperature and anisotropic oxides\nwhich demonstrate low expansion due to microcracking. Conditions for\nfailure of coatings by either cracking or spallation due to thermal\nmismatch are evaluated.", "publisher": "NASA", "publication_date": "1987" }, { "id": "authors:hq2mj-yhs05", "collection": "authors", "collection_id": "hq2mj-yhs05", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140916-213750146", "type": "book_section", "title": "Mechanical Properties of Ga_(1\u2013x)In_xAs", "book_title": "Semiconductor-on-Insulator and Thin Film Transistor Technology", "author": [ { "family_name": "Guruswamy", "given_name": "S.", "clpid": "Guruswamy-S" }, { "family_name": "Hirth", "given_name": "J. P.", "clpid": "Hirth-J-P" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Chiang", "given_name": "A.", "clpid": "Chiang-A" }, { "family_name": "Geis", "given_name": "M. W.", "clpid": "Geis-M-W" }, { "family_name": "Pfeiffer", "given_name": "L.", "clpid": "Pfeiffer-L" } ], "abstract": "Substantial solid solution strengthening of GaAs by In acting as InAs_4 units has recently been predicted. This strengthening could account for the reduction of dislocation density in GaAs single crystals grown from the melt. High temperature hardness measurements up to 700\u00baC have been carried out on (100) GaAs and Ga_(0.9975)In_(0.0025)As wafers. Results show a significant strengthening effect in In-doped GaAs even at concentration levels of about 0.2 wt%. A temperature independent flow stress region is observed for both these alloys. The In-doped GaAs shows a higher plateau stress level compared to the undoped GaAs. The results are consistent with the solid solution strengthening model.", "doi": "10.1557/PROC-53-329", "isbn": "0931837189", "publisher": "Materials Research Society", "place_of_publication": "Pittsburgh, PA", "publication_date": "1986", "pages": "329-336" }, { "id": "authors:rgk4b-vj048", "collection": "authors", "collection_id": "rgk4b-vj048", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140916-203214745", "type": "book_section", "title": "Surface Energy as an Indicator of Interfacial Mechanical Response", "book_title": "Tailoring multiphase and composite ceramics", "author": [ { "family_name": "Godard", "given_name": "H. T.", "clpid": "Godard-H-T" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Tressler", "given_name": "Richard E.", "clpid": "Tressler-R-E" }, { "family_name": "Messing", "given_name": "Gary L.", "clpid": "Messing-G-L" }, { "family_name": "Pantano", "given_name": "Carlo G.", "clpid": "Pantano-C-G" }, { "family_name": "Newnham", "given_name": "Robert E.", "clpid": "Newnham-R-E" } ], "abstract": "Contact angles between silicon and a variety of silicon carbide-based\nfibers have been measured and correlated to the mechanical behavior of the\nfiber-matrix interface. Infiltration by the molten silicon into the fibers\nand/or reaction with excess carbon to form silicon carbide gives rise to low\ncontact angles and high toughness interfaces. It is suggested that the high\ntoughness of the interface is morphology-controlled.", "doi": "10.1007/978-1-4613-2233-7_54", "isbn": "0306423812", "publisher": "Plenum Press", "place_of_publication": "New York, NY", "publication_date": "1986", "pages": "687-696" }, { "id": "authors:3ce7d-tbj70", "collection": "authors", "collection_id": "3ce7d-tbj70", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210114-140535869", "type": "book_section", "title": "Observations of Intergranular, Crack Deflection Toughening Mechanisms in Silicon Carbide", "book_title": "Fracture in Ceramic Materials: Toughening Mechanisms, Machining Damage, Shock", "author": [ { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Evans", "given_name": "A. G.", "clpid": "Evans-Anthony-Glyn" } ], "contributor": [ { "family_name": "Evans", "given_name": "Anthony Glyn", "clpid": "Evans-Anthony-Glyn" } ], "abstract": "The fracture toughness of three silicon carbide-based materials were examined in the light of operative toughening mechanisms. Crack deflection along grain boundaries in a hot-pressed SiC-Al\u2082O\u2083 and a hot-pressed SiC-ZrO\u2082 provided notable toughness increases compared with a sintered alpha -SiC, which fractures transgranularly. The existence of a crack deflection mechanism was confirmed using scanning electron microscopy.", "isbn": "9780815510055", "publisher": "Noyes Publications", "place_of_publication": "Park Ridge, NJ", "publication_date": "1984", "pages": "99-108" }, { "id": "authors:czbme-g7c19", "collection": "authors", "collection_id": "czbme-g7c19", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140916-143540784", "type": "book_section", "title": "Microcracking Contributions to the Toughness of ZrO_2-Based Ceramics", "book_title": "Science and technology of zirconia II", "author": [ { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Claussen", "given_name": "Nils", "clpid": "Claussen-N" }, { "family_name": "R\u00fchle", "given_name": "Manfred", "clpid": "R\u00fchle-M" }, { "family_name": "Heuer", "given_name": "Arthur Harold", "clpid": "Heuer-A-H" } ], "abstract": "Analyses are presented to evaluate two microcrack toughening situations in\nZr_O2-based ceramics. The first analysis considers toughening due to stress-induced\nmicrocracking of residually strained monoclinic ZrO_2 particles. The second assesses\nmicrocracking that occurs as a consequence of the stress-induced tetragonal-monoclinic\ntransformation. Both toughening mechanisms are characterized by a\npermanent dilatational strain and a modulus reduction; however, only the latter may\nresult in a toughness enhancement or reduction. Conditions under which toughness\nenhancement and reduction are observed are established. The magnitudes of\ntoughening increases from transformation-toughening and microcrack-toughening\nare also compared.", "isbn": "0916094642", "publisher": "American Ceramic Society", "place_of_publication": "Columbus, OH", "publication_date": "1984", "pages": "293-305" }, { "id": "authors:5ye8q-q9a63", "collection": "authors", "collection_id": "5ye8q-q9a63", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140916-115438203", "type": "book_section", "title": "Toughening Mechanisms for Ceramics in Automotive Applications", "book_title": "Proceedings of the 12th Automotive Materials Conference", "author": [ { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Smothers", "given_name": "William", "clpid": "Smothers-W" } ], "abstract": "Insuring the strength of ceramic materials in automotive applications requires the\nunderstanding of the operative strength-determining parameters, one of which is\nthe fracture toughness. Toughening mechanisms in ceramics will be reviewed here,\nincluding crack shielding and crack interaction mechanisms. Also covered in this\nreview will be a discussion of surface strengthening effects, as well as recent\ndevelopments in ceramic matrix fiber composites. Experimental examples of each\nof the toughening mechanisms will be presented.", "doi": "10.1002/9780470320211.ch12", "isbn": "9780470374108", "publisher": "Wiley", "place_of_publication": "Hoboken, NJ", "publication_date": "1984", "pages": "408-439" }, { "id": "authors:x27xf-n8x34", "collection": "authors", "collection_id": "x27xf-n8x34", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210114-141918270", "type": "book_section", "title": "On the Crack Growth Resistance of Microcracking Brittle Materials", "book_title": "Fracture in Ceramic Materials: Toughening Mechanisms, Machining Damage, Shock", "author": [ { "family_name": "Evans", "given_name": "A. G.", "clpid": "Evans-Anthony-Glyn" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" } ], "contributor": [ { "family_name": "Evans", "given_name": "Anthony Glyn", "clpid": "Evans-Anthony-Glyn" } ], "abstract": "A mechanics model of microcrack toughening has been presented. The model predicts the magnitude of microcrack toughening as well as the existence of R-curve effects. The toughening is predicated on both the elastic modulus diminution in the microcrack process zone and the dilatation induced by microcracking. The modulus effect is relatively small and process zone size independent. The dilatational effect is potentially more substantial, as well as being the primary source of the R-curve. The dilatational contribution is also zone size dependent. The analysis demonstrates that microcrack toughening is less potent than transformation toughening, by virtue of the damaging effect of microcracks on the material ahead of the crack.", "isbn": "9780815510055", "publisher": "Noyes Publications", "place_of_publication": "Park Ridge, NJ", "publication_date": "1984", "pages": "109-136" }, { "id": "authors:3mj39-rk708", "collection": "authors", "collection_id": "3mj39-rk708", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140916-210935712", "type": "book_section", "title": "A Statistical Analysis of Crack Deflection as a Toughening Mechanism in Ceramic Materials", "book_title": "Measurements, transformations, and high-temperature fracture", "author": [ { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Evans", "given_name": "A. G.", "clpid": "Evans-A-G" }, { "family_name": "Drory", "given_name": "M. D.", "clpid": "Drory-M-D" } ], "contributor": [ { "family_name": "Bradt", "given_name": "Richard C.", "clpid": "Bradt-R-C" } ], "abstract": "A coupled stress intensity probabilistic treatment of toughening\nby crack deflection around spherical second phase particles\nis presented. Both the tilting of the crack around particles and\nThe twisting of the crack front between particles have been evaluated.\nImportant features of the analysis include particle volume\nfraction effects on the toughening increment, and the absence of\na particle size effect.", "isbn": "0306410222", "publisher": "Plenum Press", "place_of_publication": "New York, NY", "publication_date": "1983", "pages": "77-91" }, { "id": "authors:5fhrq-tj346", "collection": "authors", "collection_id": "5fhrq-tj346", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140918-150539131", "type": "book_section", "title": "High temperature properties of sintered alpha silicon carbide", "author": [ { "family_name": "Coppola", "given_name": "J. A.", "clpid": "Coppola-J-A" }, { "family_name": "Srinivasan", "given_name": "M.", "clpid": "Srinivasan-M" }, { "family_name": "Faber", "given_name": "K. T.", "orcid": "0000-0001-6585-2536", "clpid": "Faber-K-T" }, { "family_name": "Smoak", "given_name": "R. H.", "clpid": "Smoak-R-H" } ], "contributor": [ { "family_name": "S\u014dmiya", "given_name": "Shigeyuki", "clpid": "S\u014dmiya-S" }, { "family_name": "Sait\u014d", "given_name": "Shinroku", "clpid": "Sait\u014d-S" } ], "abstract": "Sintered alpha silicon carbides are being developed to meet the requirements\nof conventional and advanced heat engine systems. Through pressureless sintering,\nlow cost, near-net complex shapes requiring little finish grinding can be\nfabricated from this form of silicon carbide.\nThe use of ceramics such as silicon carbide as engine components requires\ndetailed data collection and understanding of material's performance especially\nat high temperatures. Much data have been generated on sintered alpha SiC (1-5)\nover the past two years. Specifically, it has been shown that the fast fracture\nstrength of a sintered alpha silicon carbide tested in air is constant from room\ntemperature to above 1400\u00b0 (2) and that an increase in strength has been\nobserved when tested in argon (1,2).\nSome physical properties of sintered alpha SiC are listed in Table 1. These\ndata are typical of the high purity, low porosity nature of a densified silicon\ncarbide. Figure 1 shows the four point bend strength of sintered alpha SiC as\na function of temperature.\nIt has been shown (3,4) that the strength of fine grain, less than 10 \u00b5m\naverage grain size, sintered alpha SiC is presently limited by the presence of\nprocessing defects. It has also been reported (4) that evidence of slow crack\ngrowth has been observed at 1500 \u00b0C in air for sintered alpha SiC having an\nextremely coarse grain structure. This coarse grain microstructure was caused\nby post-sintering heat treatment of a fine grain material promoting the occurance\nof exaggerated grain growth. An evaluation of various experimental techniques\nfor determining the fracture toughness (K_(Ic)) of sintered alpha SiC has also been\nreported (5).\nThis paper presents further work on the high temperature properties of\na sintered alpha SiC. Specifically, data on the oxidation behavior and stress-rupture\nas a function of temperature and atmosphere will be presented.", "publisher": "Gakujutsu Bunken Fukyu-kai", "publication_date": "1979" } ]