Download or read book Boron Carbide Continuous Filaments written by A. Gatti and published by . This book was released on 1965 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this program was to develop and evaluate a process for producing continuous lengths of boron carbide filament having tensile strengths approaching 500,000 psi and elastic moduli close to that of bulk boron carbide (60-70 million psi) are being developed. Filaments were produced by depositing the reaction product of born trichloride, hydrogen and methane on a heated tungsten filamentary substrate which had a boron primer coat. Excess hydrogen was used as a carrier gas. Initial evaluation of the boron carbide filaments as a reinforcement for epoxy resins indicated that no wetting problem between the filament/resin existed, that the transfer of stresses to the filaments was efficient, and that the wet strength problem, which is characteristic of boron/epoxy composites, may not be as severe when boron carbide filaments are used. Characterization studies were performed on typical filament specimens, and the results indicated an amorphous structure with two prevailing surface morphologies, (1) granular or (2) nodular, depending on the mode of nucleation. The final apparatus evolved for the production of B4C filaments utilized a high mass flow gas system in a seven stage reactor which had a deposition zone twenty-one inches long.
Download or read book Boron Carbide Continuous Filaments Part Ii written by and published by . This book was released on 1966 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this program was to develop and evaluate a process for producing continuous lengths of boron carbide filament having tensile strengths approaching 500,000 psi and elastic moduli close to that of bulk boron carbide (60-70 million psi) are being developed. Filaments were produced by depositing the reaction product of born trichloride, hydrogen and methane on a heated tungsten filamentary substrate which had a boron primer coat. Excess hydrogen was used as a carrier gas. Initial evaluation of the boron carbide filaments as a reinforcement for epoxy resins indicated that no wetting problem between the filament/resin existed, that the transfer of stresses to the filaments was efficient, and that the wet strength problem, which is characteristic of boron/epoxy composites, may not be as severe when boron carbide filaments are used. Characterization studies were performed on typical filament specimens, and the results indicated an amorphous structure with two prevailing surface morphologies, (1) granular or (2) nodular, depending on the mode of nucleation. The final apparatus evolved for the production of B4C filaments utilized a high mass flow gas system in a seven stage reactor which had a deposition zone twenty-one inches long.
Download or read book Research on Structure Characterization of Continuous Filament Materials written by R. P. I. Adler and published by . This book was released on 1967 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Characterization studies of vapor deposited boron carbide, titanium diboride, and silicon carbide filaments were performed. Boron carbide, with maximum strengths of around 100,000 psi, contained large amounts of pyrolytic graphite. Titanium diboride had a coating of TiB2 on the substrate but only had maximum strengths of 140,000 psi. Silicon carbide, consisting primarily of a fine grained polycrystalline Beta-SiC coating on a W substrate, could be produced having 300,000 psi failure stresses but the highest strengths (385,000 psi) were achieved with a boron dopant. Thermal exposures of SiC filaments to temperatures in excess of 1000C for short periods of time in an inert argon atmosphere can reduce the failure strengths from over 300,000 psi to below 100,000 psi. (Author).
Download or read book A Study of Low Density High Strength High Modulus Filaments and Composites written by J. A. Alexander and published by . This book was released on 1966 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: This program has been concerned with the fabrication and testing of three types of advanced composite materials: (1) Metals reinforced with continuous filaments (2) Metals reinforced with single crystal whiskers (3) Multilaminar composites consisting of alternate layers of metal and ceramic. In order to fabricate the filament composites, continuous boron, and batch boron carbide, and silicon carbide filaments were synthesized at GTC. Electrodeposited nickel was reinforced by both 4 v/o tungsten wire and 20-30 v/a boron filament in aligned configuration. Tensile testing of these composites yielded tensile strengths in all cases that exceeded theoretical values. calculated by adding the volume-weighted tensile strengths of the components. This effect was most pronounced with the boron filament. Sapphire whisker composites of powder metallurgically produced Al-6Si_matrix and electrodeposited nickel were fabricated and tested. In all cases the whiskers were more or less randomly aligned. Contents up to 16 weight percent whiskers in Al-6Si strengthened the matrix. Approximately 10 weight percent of whiskers in electrodeposited nickel did not strengthen this matrix, although heat treatments did improve the as formed strength. Work was carried out on the techniques for depositing columbium films and alumina films to form alumina-columbium multilaminar composites. However no composite specimens were fabricated.
Download or read book Technical Abstract Bulletin written by Defense Documentation Center (U.S.) and published by . This book was released on 1967 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Methods of Producing Continuous Boron Carbide Fibers written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods of producing continuous boron carbide fibers. The method comprises reacting a continuous carbon fiber material and a boron oxide gas within a temperature range of from approximately 1400.degree. C. to approximately 2200.degree. C. Continuous boron carbide fibers, continuous fibers comprising boron carbide, and articles including at least a boron carbide coating are also disclosed.
Download or read book Study of the Growth Parameters Involved in Synthesizing Boron Carbide Filaments written by A. Gatti and published by . This book was released on 1965 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Synthesis of Boron Carbide Filaments written by A. Gatti and published by . This book was released on 1964 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Composites written by George Lubin and published by Springer Science & Business Media. This book was released on 2013-11-27 with total page 788 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of advanced composites, tion. Forecasts indicate that the potential spanning a brief period from inception to usage in automobiles in the early 1990's will application of only 15 to 20 years, epitomizes amount to millions of pounds of advanced the rapidity with which a generation's change composites. in the state-of-the-art can take place. This is in We find ourselves in a peculiar position. marked contrast to past history, in which it The hardware capability is progressing so has usually required 25 years or more of rapidly that the knowledge and familiarity of research before a new structural material was the designer can hardly keep pace. We have an technologically ready. obligation now not just to mature this ad In the mid-1950's the U.S. Air Force identi vanced technology and its applications, but fied the promise for early application of a new also to communicate the state-of-the-art to the class of materials-advanced composites designer in a form in which it can be applied and established its feasibility by the fabrication readily to practical structures. I believe that of raw fiber with exceptional strength- and this book, Handbook of Composites, will modulus-to-weight ratios. The practical fabrica clearly provide a portion of this missing link.
Download or read book SURFACE FINISHES FOR BORON FILAMENTS written by Ralph L. Hough and published by . This book was released on 1966 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Boron filaments were surface finished with inorganic thin films to provide improved adhesion to organic resins and to provide improved high temperature oxidation resistance in boron filament reinforced plastic composites. Surfacing materials included aluminum, titanium, silicon carbide, titanium nitride, titanium diboride, nickel and boron-carbon. These materials, with the exception of boron-carbon were selected because the oxidation products are more resistant to moisture than boron oxides normally occurring on boron filaments. The finishes were applied to the boron filaments by a continuous vapordeposition glow discharge process. Of the finishes examened, those of silicon carbide, silicon and titanium nitride exhibited superior oxidation resistance and greatly improved resin bondability over uncoated boron. (Author).
Download or read book Summary of the Eleventh Meeting of the Refractory Composites Working Group written by Darrell R. James and published by . This book was released on 1966 with total page 1496 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interfacial Stability of Silicon Carbide Coated Boron Filament Reinforced Metals written by M. Basche and published by . This book was released on 1969 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The degradation of boron filament reinforced aluminum composites at temperatures over 400 C severely limits this material to relatively low-temperature applications. In order to extend the elevated temperature usefulness of such composites boron filament was coated with a diffusion and oxidation inhibiting coating of ?-silicon carbide. The coating was applied by thermally decomposing a halogenated silane compound on the surface of previously prepared boron filaments. Electron microprobe analysis showed that the boron had diffused part way through the silicon carbide layer during the deposition process at approximately 1200 C. The ultimate tensile strengths of the coated fibers, however, were found to be approximately the same as the uncoated fibers, namely, 450,000 to 550,000 psi.
Download or read book Torsional Modulus of Boron and Silicon Carbide Filaments written by James M. Dillahunty and published by . This book was released on 1970 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of High Modulus High Strength Filament Materials by Deposition Techniques written by L. G. Davies and published by . This book was released on 1964 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of the Growth Parameters Involved in Synthesizing Boron Carbide Filaments written by A. Gatti and published by . This book was released on 1965 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Boron Carbide written by Kolan Madhav Reddy and published by . This book was released on 2020-04-04 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Boron carbide is a superhard and lightweight ceramic material. As a result of these characteristics, it used as a protective component in bulletproof vests, tank armour and also has many other industrial applications (eg: tooling, abrasives). Research on boron carbide remains active given a long-standing challenge to understand its complex failure behavior in extreme environments owing to its unique microstructure and mechanical properties, where many current efforts are underway to improve its behavior through microstructure alteration via additives that form secondary phases, chemical doping, and altering the chemical composition of the boron-to-carbon ratio in the crystal structure. This book covers some of the key challenges involving boron carbide that are currently being studied by many materials scientists and ceramists. The authors who are active in this research field have prepared the chapters for this book and specific topics covered highlight the state-of-the art research in structure, processing, properties and applications. The organization of the book is designed to provide an easy understanding for students and professionals interested in advanced material for novel applications.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1980 with total page 730 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
