Download or read book Properties of Silicon Carbide Fiber Reinforced Silicon Nitride Matrix Composites written by Ramakrishna T. Bhatt and published by . This book was released on 1988* with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mechanical properties of NASA Lewis Research Center developed SiC/RBSN composites and their thermal and environmental stability have been studied. The composites consist of nearly 30 vol % of aligned 142 um diameter chemically vapor-deposited SiC fibers in a relatively porous silicon nitride matrix. In the as-fabricated condition, the unidirectional and two-dimensional composites exhibited metal-like stress-strain behavior, graceful failure, and showed improved properties when compared with unreinforced matrix of comparable density. Furthermore, the measured room temperature tensile properties were relatively independent of tested volume and were unaffected by artificial notches normal to the loading direction or by thermal shocking from temperatures up to 1100C. The four point bend strength data measured as a function of temperature to 1400C in air showed that as-fabricated strength was maintained to 1200C. At 1400C, however, nearly 15 percent loss in strength was observed. Measurement of room temperature tensile strength after 100 hr exposure at temperatures to 1400C in a nitrogen environment indicated no loss from the as-fabricated composite strength. (JES).

Download or read book Effects of Interface Coating and Nitride Enhancing Additive on Properites of Hi Nicalon SiC Fiber Reinforced Reaction bonded Silicon Nitride Composites written by Ramakrishna T. Bhatt and published by . This book was released on 2000 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Strong and tough Hi-Nicalon SiC fiber reinforced reaction-bonded silicon nitride matirix composites (SiC/RBSN) have been fabricated by the fiber lay-up approach. Commercially available uncoated and PBN, PBN/Si-rich PBN, and BN/SiC coated SiC Hi-Nicalon fiber tows were used as reinforcement. The composites contained ~24 vol % of aligned 14 ♯m diameter SiC fibers in a porous RBSN matrix. Both one- and two-dimensional composites were characterized. The effects of interface coating composition, and the nitridation enhancing additive, NiO, on the room temperature physical, tensile, and interfacial shear strenght properties of SiC/RBSN matrix composites were evaluated. Results indicate that all three coated fibers, the thickness of the coating decreased from the outer periphery to the interior of the tows, and that from 10 to 30 percent of the fibers were not covered with the interface coating.

Download or read book Handbook of Ceramic Composites written by Narottam P. Bansal and published by Springer Science & Business Media. This book was released on 2006-08-25 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: This valuable handbook has been compiled by internationally renowned researchers in the field. Each chapter is focused on a specific composite system or a class of composites, presenting a detailed description of processing, properties, and applications.

Download or read book PROCESSING AND PROPERTIES OF SILICON CARBIDE WHISKER REINFORCED SILICON NITRIDE CERAMIC MATRIX COMPOSITES SILICON CARBIDE WHISKER REINFORCED SILICON NITRIDE written by STEPHEN DOUGLAS NUNN and published by . This book was released on 1991 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: MgAl\sb2Si\sb4O\sb6N\sb4$, and the matrix and reinforcing phases. The fracture toughness appeared to be controlled by the ability of cracks to propagate along the intergranular phase.

Download or read book Thermal Effects on the Mechanical Properties of SiC Fiber Reinforced Reaction Bonded Silicon Nitride Matrix SiC RBSN Composites written by R. T. Bhatt and published by . This book was released on 1988 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The elevated temperature four-point flexural strength and the room temperature tensile and flexural strength properties after thermal shock were measured for ceramic composites consisting of 30 vol % uniaxially aligned 142 microns diameter SiC fibers in a reaction bonded Si3N4 matrix. The elevated temperature strengths were measured after 15 min of exposure in air at temperatures to 1400 C. The thermal shock treatment was accomplished by heating the composite in air for 15 min at temperatures to 1200 C and then quenching in water at 25 C. The results indicate no significant loss in strength properties either at temperature or after thermal shock when compared with the strength data for composites in the as-fabricated condition. (jes).

Download or read book Mechanical Properties of SiC Fiber Reinforced Reaction Bonded Si3N4 Composites written by R. T. Bhatt and published by . This book was released on 1985 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The room temperature mechanical and physical properties of silicon carbide fiber-reinforced reaction-bonded silicon nitride composites (SiC/RBSN) have been evaluated. The composites contained similiar to 23 and similiar to 40 volume fraction of aligned 140 micron diameter chemically vapor deposited SiC fibers. Preliminary results for composites tensile and bend strengths and fracture strain indicate that the composites displayed excellent properties when compared with unreinforced RBSN of comparable porosity. Fiber volume fraction showed little influence on matrix first cracking strain did influence the stresses required for matrix first cracking and for ultimate composite fracture strength. It is suggested that by reducing matrix porosity and by increasing the volume fraction of the large diameter SiC fiber, it should be possible to further improve the composite stress at which the matrix first cracks. Keywords: Ceramic powders; Composite fabrication; Microstructure; Density; Axial bend and tensile; Strength; and Integrated shear strength.

Download or read book Oxidation Effects on the Mechanical Properties of SiC Fiber Reinforced Reaction bonded Silicon Nitride Matrix Composites written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-09 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: The room temperature mechanical properties of SiC fiber reinforced reaction bonded silicon nitride composites were measured after 100 hrs exposure at temperatures to 1400 C in nitrogen and oxygen environments. The composites consisted of approx. 30 vol percent uniaxially aligned 142 micron diameter SiC fibers in a reaction bonded Si3N4 matrix. The results indicate that composites heat treated in a nitrogen environment at temperatures to 1400 C showed deformation and fracture behavior equivalent to that of the as-fabricated composites. Also, the composites heat treated in an oxidizing environment beyond 400 C yielded significantly lower tensile strength values. Specifically in the temperature range from 600 to 1000 C, composites retained approx. 40 percent of their as-fabricated strength, and those heat treated in the temperatures from 1200 to 1400 C retained 70 percent. Nonetheless, for all oxygen heat treatment conditions, composite specimens displayed strain capability beyond the matrix fracture stress; a typical behavior of a tough composite. Bhatt, Ramakrishna T. Glenn Research Center RTOP 510-01-0A...

Download or read book Interfacial Properties of Silicon Carbide Fiber Reinforced Reaction formed Silicon Carbide Matrix Composites written by Paula Jeanne Holmes and published by . This book was released on 1995 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ceramic Matrix Composites written by Krishan K. Chawla and published by Springer Science & Business Media. This book was released on 2013-11-27 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: After an introductory chapter, the processing, microstructure, and properties of various ceramic materials, reinforcements, and their composites are described. A separate chapter is devoted to processing of ceramic reinforcements, with a special emphasis on fibers. Processing of ceramic matrix composites is the next chapter, which includes novel techniques such as sol-gel processing and ceramics from polymeric precursors. The next four chapters cover the subjects of interface region in ceramic composites, mechanical and physical properties, and the role of thermal stresses and the important subject of toughness enhancement. Laminated composites made of ceramics are described in a separate chapter. Finally, a chapter is devoted to various applications of ceramic matrix composites. Throughout the text, the underlying relationships between the components of the triad: processing, microstructure, and properties are brought out. An exhaustive list of references and suggested reading is provided.

Download or read book Effects of Interface Coating and Nitride Enhancing Additive on Properties of Hi Nicalon Sic Fiber Reinforced Reaction Bonded Silicon Nitride Composite written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-27 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Strong and tough Hi-Nicalon SiC fiber reinforced reaction-bonded silicon nitride matrix composites (SiC/ RBSN) have been fabricated by the fiber lay-up approach. Commercially available uncoated and PBN, PBN/Si-rich PBN, and BN/SiC coated SiC Hi-Nicalon fiber tows were used as reinforcement. The composites contained approximately 24 vol % of aligned 14 micron diameter SiC fibers in a porous RBSN matrix. Both one- and two-dimensional composites were characterized. The effects of interface coating composition, and the nitridation enhancing additive, NiO, on the room temperature physical, tensile, and interfacial shear strength properties of SiC/RBSN matrix composites were evaluated. Results indicate that for all three coated fibers, the thickness of the coatings decreased from the outer periphery to the interior of the tows, and that from 10 to 30 percent of the fibers were not covered with the interface coating. In the uncoated regions, chemical reaction between the NiO additive and the SiC fiber occurs causing degradation of tensile properties of the composites. Among the three interface coating combinations investigated, the BN/SiC coated Hi-Nicalon SiC fiber reinforced RBSN matrix composite showed the least amount of uncoated regions and reasonably uniform interface coating thickness. The matrix cracking stress in SiC/RBSN composites was predicted using a fracture mechanics based crack bridging model. Bhatt, Ramakrishana T. and Hull, David R. and Eldridge, Jeffrey I. and Babuder, Raymond Glenn Research Center NASA/TM-2000-210211, E-12330, NAS 1.15:210211

Download or read book High Temperature Tensile Properties of Fiber Reinforced Reaction Bonded Silicon Nitride written by DA. Jablonski and published by . This book was released on 1990 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: A testing technique has been developed for measuring the tensile properties of ceramic matrix composite laminates at temperatures up to 1500°C in air. Using this technique, the tensile properties of unidirectional silicon carbide (SiC) fiber reinforced reaction bonded silicon nitride (SiC/RBSN) composite specimens were measured at 25, 1300, and 1500°C. The composite consists of nearly 30 vol % of aligned 142 μm, chemically vapor deposited SiC fibers (Textron SCS-6). The specimens used were straight section flat specimens with bonded end tabs. A specially designed gripping system was used to minimize bending moment and assured that failure always occurred in the gage section. The specimen extension was measured using a high-temperature capacitive extensometer.

Download or read book Fiber Reinforced Ceramic Composites written by K.S. Mazdiyasni and published by William Andrew. This book was released on 1990-12-31 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides the first comprehensive treatment of continuous and discontinuous ceramic fiber and whisker reinforced ceramic composites, written by 29 authorities in the field.

Download or read book Influence of Interfacial Shear Strength on the Mechanical Properties of SiC Fiber Reinforced Reaction Bonded Silicon Nitride Matrix Composites written by and published by . This book was released on 1990 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The influence of fiber/matrix interface microstructure and interfacial shear strength on the mechanical properties of a fiber-reinforced ceramic composite has been evaluated. The composite consisted of about 30 vol % uniaxially aligned 142 micron diameter SiC fibers (Textron SCS-6) in a reaction- bonded Si3N4 matrix (SiC/RBSN). The interface microstructure was varied by controlling the composite fabrication conditions and by heat treating the composite in an oxidizing environment. Interfacial shear strength was determined by the matrix crack spacing method. The results of microstructural examination indicate that the carbon-rich coating provided with the as-produced SiC fibers was stable in composites fabricated at 1200 C in a nitrogen or in a nitrogen plus 4 percent hydrogen mixture for 40 hr. However this coating degraded in composites fabricated at 1350 C in N2 + 4%H2 for 40 and 72 hr and also in composites heat treated in an oxidizing environment at 600 C for 100 hr after fabrication at 1200 C in a nitrogen. It was determined that degradation occurred by carbon removal which in turn had a strong influence on interfacial shear strength and other mechanical properties. Specifically, as the carbon coating was removed, the composite interfacial shear strength, primary elastic modulus, first matrix cracking stress, and ultimate tensile strength decreased, but the first matrix cracking strain remained nearly the same. Keywords: Ceramic matrix composites; Interfacial shear strength; Mechanical properties.

Download or read book Effects of Fiber Content on Mechanical Properties of CVD SiC Fiber Reinforced Strontium Aluminosilicate Glass Ceramic Composites written by Narottam P. Bansal and published by . This book was released on 1996 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Temperature Ceramic Matrix Composites written by Walter Krenkel and published by Wiley-VCH. This book was released on 2001 with total page 1044 pages. Available in PDF, EPUB and Kindle. Book excerpt: The extreme high temperature stability and damage tolerance of materials and components required for space, terrestrial, energetic and many other applications can only be achieved by ceramic materials. All over the world research is going on to develop ceramics with quasiductile behaviour. The materials with the highest potential for high temperature applications are fibre reinforced ceramic matrix composites (CMC). The international conference HT-CMC 4 in Munich will continue the tradition of its successful predecessor meetings held in Bordeaux (France, 1993), Santa Barbara (USA, 1995) and Osaka (Japan, 1998). This conference series has been recognized as the central meeting event in high temperature CMC science and technology and demonstrates the great interest in research and development on reinforced ceramics. The Proceedings of this conference will therefore be a valuable reference for every materials scientist or engineer involved in this field of high-tech materials development.

Download or read book Mechanical behavior of a SiC fiber Si3N4 composite written by Jeffrey J. Swab and published by . This book was released on 1990 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examines mechanical properties of a silicon carbide fiber/silicon nitride matrix composite.

Download or read book High Temperature Mechanical Behaviour of Ceramic Composites written by Karl Jakus and published by Elsevier. This book was released on 1995-06-28 with total page 569 pages. Available in PDF, EPUB and Kindle. Book excerpt: High Temperature Mechanical Behavior of Ceramic Composites provides an up-to-date comprehensive coverage of the mechanical behavior of ceramic matrix composites at elevated temperatures. Topics include both short-term behavior (strength, fracture toughness and R-curve behavior) and long-term behavior (creep, creep-fatigue, delayed failure and lifetime). Emphasis is on a review of fundamentals and on the mechanics and mechanisms underlying properties. This is the first time that complete information of elevated temperature behavior of ceramic composites has ever been compacted together in a single volume. Of particular importance is that each chapter, written by internationally recognized experts, includes a substantial review component enabling the new material to be put in proper perspective. Shanti Nair is Associate Professor at the Department of Mechanical Engineering at the University of Massachusetts at Amherst. Karl Jakus is Professor at the University of Massachusetts at Amherst.