Download or read book Pressureless Sintering of Boron Carbide Whisker Reinforced Alumina Matrix Composites written by Xuan Lin and published by . This book was released on 1995 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Suspension Processing and Pressureless Sintering of Silicon Carbide Whisker reinforced Alumina matrix Composites written by Hae-Weon Lee and published by . This book was released on 1990 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Suspension processing and pressureless sintering of silicon carbide whisker reinforced alumina matrix composites Ph D Universityof Florida written by Hae-Weon Lee and published by . This book was released on 1990 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Method for Preparing Configured Silicon Carbide Whisker reinforced Alumina Ceramic Articles written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A ceramic article of alumina reinforced with silicon carbide whiskers suitable for the fabrication into articles of complex geometry are provided by pressureless sintering and hot isostatic pressing steps. In accordance with the method of the invention a mixture of 5 to 10 vol. % silicon carbide whiskers 0.5 to 5 wt. % of a sintering aid such as yttria and the balance alumina powders is ball-milled and pressureless sintered in the desired configuration in the desired configuration an inert atmosphere at a temperature of about 1800.degree. C. to provide a self-supporting configured composite of a density of at least about 94% theoretical density. The composite is then hot isostatically pressed at a temperature and pressure adequate to provide configured articles of at least about 98% of theoretical density which is sufficient to provide the article with sufficient strength and fracture toughness for use in most structural applications such as gas turbine blades, cylinders, and other components of advanced heat engines.
Download or read book Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS)* at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dis semination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this jOint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volumes were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 40 (thesis year 1995) a total of 10,746 thesis titles from 19 Canadian and 144 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this impor tant annual reference work. While Volume 40 reports theses submitted in 1995, on occasion, certain uni versities do report theses submitted in previous years but not reported at the time.
Download or read book 20th Annual Conference on Composites Advanced Ceramics Materials and Structures A Volume 17 Issue 3 written by John B. Wachtman and published by John Wiley & Sons. This book was released on 2009-09-28 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is part of the Ceramic Engineering and Science Proceeding (CESP) series. This series contains a collection of papers dealing with issues in both traditional ceramics (i.e., glass, whitewares, refractories, and porcelain enamel) and advanced ceramics. Topics covered in the area of advanced ceramic include bioceramics, nanomaterials, composites, solid oxide fuel cells, mechanical properties and structural design, advanced ceramic coatings, ceramic armor, porous ceramics, and more.
Download or read book Ceramic Matrix Composites written by I M Low and published by Woodhead Publishing. This book was released on 2006-01-25 with total page 633 pages. Available in PDF, EPUB and Kindle. Book excerpt: The advent of engineering-designed polymer matrix composites in the late 1940s has provided an impetus for the emergence of sophisticated ceramic matrix composites. The development of CMCs is a promising means of achieving lightweight, structural materials combining high temperature strength with improved fracture toughness, damage tolerance and thermal shock resistance. Considerable research effort is being expended in the optimisation of ceramic matrix composite systems, with particular emphasis being placed on the establishment of reliable and cost-effective fabrication procedures. Ceramic matrix composites consists of a collection of chapters reviewing and describing the latest advances, challenges and future trends in the microstructure and property relationship of five areas of CMCs. Part one focuses on fibre, whisker and particulate-reinforced ceramic matrix composites, part two explores graded and layered ceramics, while the five chapters in part three cover nanostructured CMCs in some detail. Refractory and speciality ceramic composites are looked at in part four, with chapters on magnesia-spinel composite refractory materials, thermal shock of CMCs and superplastic CMCs. Finally, part four is dedicated to non-oxide ceramic composites. Ceramic matrix composites is a comprehensive evaluation of all aspects of the interdependence of processing, microstructure, properties and performance of each of the five categories of CMC, with chapters from experienced and established researchers. It will be essential for researchers and engineers in the field of ceramics and more widely, in the field of inorganic materials. Looks at the latest advances, challenges and future trends Compiled by experienced and established researchers in the field Essential for researchers and engineers
Download or read book Field Assisted Sintering of Refractory Carbide Ceramics and Fiber Reinforced Ceramic Matrix Composites written by Sean Gephart and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The sintering behaviors of silicon carbide (SiC) and boron carbide (B4C) based materials were investigated using an emerging sintering technology known as field assisted sintering technology (FAST), also known as spark plasma sintering (SPS) and pulse electric current sintering (PECS). Sintering by FAST utilizes high density electric current, uniaxial pressure, and relatively high heating rate compared to conventional sintering techniques.This effort investigated issues of scaling from laboratory FAST system (25 ton capacity) to industrial FAST system (250 ton capacity), as well as exploring the difference in sintering behavior of single phase B4C and SiC using FAST and conventional sintering techniques including hot-pressing (HP) and pressure-less sintering (PL). Materials were analyzed for mechanical and bulk properties, including characterization of density, hardness, fracture toughness, fracture (bend) strength, elastic modulus and microstructure. A parallel investigation was conducted in the development of ceramic matrix composites (CMC) using SiC powder impregnation of fiber compacts followed by FAST sintering.The FAST technique was used to sinter several B4C and SiC materials to near theoretical density. Preliminary efforts established optimized sintering temperatures using the smaller 25 ton laboratory unit, targeting a sample size of 40 mm diameter and 8 mm thickness. Then the same B4C and SiC materials were sintered by the larger 250 ton industrial FAST system, a HP system, and PL sintering system with a targeted dense material geometry of 4x4x0.315 inches3 (101.6x101.6x8 mm3). The resulting samples were studied to determine if the sintering dynamics and/or the resulting material properties were influenced by the sintering technique employed. This study determined that FAST sintered ceramic materials resulted in consistently higher averaged values for mechanical properties as well as smaller grain size when compared to conventionally sintered materials. While FAST sintered materials showed higher average values, in general they also showed consistently larger variation in the scattered data and consequently larger standard deviation for the resulting material properties. In addition, dynamic impact testing (V50 test) was conducted on the resulting materials and it was determined that there was no discernable correlation between observed mechanical properties of the ceramic materials and the resulting dynamic testing.Another study was conducted on the sintering of SiC and carbon fiber reinforced SiC ceramic matrix composites (CMC) using FAST. There has been much interest recently in fabricating high strength, low porosity SiC CMC's for high temperature structural applications, but the current methods of production, namely chemical vapor infiltration (CVI), melt infiltration (MI), and polymer infiltration and pyrolysis (PIP), are considered time consuming and involve material related shortcomings associated with their respective methodologies. In this study, SiC CMC's were produced using the 25 ton laboratory unit with a target sample size of 40 mm diameter and 3 mm thickness, as well as on the larger 250 ton industrial FAST system targeting a sample size of 101.6x101.6x3 mm3 to investigate issues associated with scaling. Several sintering conditions were explored including: pressure of 35-65 MPa, temperature of 1700-1900°C, and heating rates between 50-400°C/min. The SiC fibers used in this study were coated using chemical vapor deposition (CVD) with boron nitride (BN) and pyrolytic carbon to act as a barrier layer and preserve the integrity of the fibers during sintering. Then the barrier coating was coated by an outer layer of SiC to enhance the bonding between the fibers and the SiC matrix. Microstructures of the sintered samples were examined by FE-SEM. Mechanical properties including flexural strength-deflection and stress-strain were characterized using 4-point bend testing. Tensile testing was performed on the larger 101.6x101.6x3 mm samples. The microstructures of samples sintered using the 25 ton laboratory FAST system showed a reduction in porosity and good adhesion between the fiber-fiber and fiber-matrix interface. The microstructures of samples sintered on the 250 ton industrial FAST system showed a reduction in porosity, but there was visible reaction of the fiber and fiber coatings with the surrounding matrix. Additionally, there was significant radial cracking of the fibers visible in the microstructures.There is gap in the understanding of sintering behavior between laboratory and industrial scale FAST systems. The vast majority of publications on FAST sintering have been primarily focused on small sample geometries (20 mm diameter, less than 3 mm thick). A study was coordinated to investigate the thermal properties during heating and cooling using a 250 ton industrial FAST system at 900°C using B4C and SiC materials inside the graphite die assembly. The thermal properties were then compared to the resulting material properties of the identically sintered B4C and SiC to approximately 94% relative density, at a temperature of 1950°C, pressure of 45 MPa, 10 minute hold, and heated at a rate of 100°C/min. The study determined that at 900°C there were significant thermal gradients within the system for the examined materials, and that these gradients correlated well with the material property difference of the samples sintered at higher temperatures where the gradients are presumably larger due to an increase in radiative heat loss. The observed temperatures throughout the graphite were significantly different between B4C and SiC. These temperatures also correlated well with the material properties of the sintered products which showed more substantial variation for B4C when compared to SiC which was overall less affected by thermal gradients. This was attributed to the intrinsic thermal conductivity difference between the two subject materials which was manifested as thermal gradients throughout the material and graphite die assembly. Additionally, both the observed temperature gradients throughout the graphite die assembly and the difference in temperature reading between the optical pyrometer and thermocouples were significantly larger for the 250 ton FAST system than previous publications have demonstrated experimentally or via modeling of smaller laboratory scale systems. The findings from this work showed that relative to conventional sintering methods, the FAST process demonstrated comparable or improved material and mechanical properties with a significantly shorter processing cycle. However, the results demonstrated on the 25 ton laboratory scale unit were significantly different compared to results for the same materials sintered using the 250 ton industrial scale unit. The temperature gradients observed on the 250 ton FAST unit were significantly larger than previous reports on smaller FAST units. This result showed future efforts to scale up the FAST sintering process while maintaining similar results will require careful attention to minimizing temperature gradients. This could potentially be achieved by reducing radiative heat loss during processing and/or optimizing the graphite die design and implementing heat spreaders in specific locations dependent on the host material's thermal and electrical properties as well as the sample geometry.
Download or read book The Investigation of Pressureless Sintered Boron Carbide silicon Carbide Composites written by Zhengfei Chen and published by . This book was released on 2006 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aluminum Nitride silicon Carbide Whisker Composites written by and published by . This book was released on 1990 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aluminum nitride -- silicon carbide whisker composites with up to 20 vol % whiskers were fabricated by pressureless sintering (1750°--1800°C) and by hot-pressing (1700°--1800°C). Silicon carbide whiskers were found to degrade depending on the type of protective powder bed used during sintering. Whiskers were found to degraded in high oxygen containing samples by reaction with sintering additives. Whisker degradation was also due to the formation of silicon carbide -- aluminum nitride solid solution. No whisker degradation was observed in hot-pressed samples. For these samples Young's modulus and fracture toughness were measured. A 33% increase in the fracture toughness was measured by the indentation technique for a 20 vol % whisker composite. Operative toughening mechanisms were investigated using scanning electron microscopy. Crack deflection and whisker bridging were the dominant mechanisms. It was also shown that load transfer from matrix to whiskers can be a contributing factor to toughening. 88 refs., 34 figs., 11 tabs.
Download or read book Mechanical Properties of Boron Carbide Particle Reinforced Aluminum Matrix Composites written by Emre Can Yürüker and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 16th Annual Conference on Composites and Advanced Ceramic Materials Part 1 of 2 Volume 13 Issue 7 8 written by John B. Wachtman and published by John Wiley & Sons. This book was released on 2009-09-28 with total page 581 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is part of the Ceramic Engineering and Science Proceeding (CESP) series. This series contains a collection of papers dealing with issues in both traditional ceramics (i.e., glass, whitewares, refractories, and porcelain enamel) and advanced ceramics. Topics covered in the area of advanced ceramic include bioceramics, nanomaterials, composites, solid oxide fuel cells, mechanical properties and structural design, advanced ceramic coatings, ceramic armor, porous ceramics, and more.
Download or read book A Material Characterization of a Silicon Carbide Whisker Reinforced Aluminum Metal matrix Composite with an Emphasis on Cyclic Bending written by Sean Michael Fleming and published by . This book was released on 1993 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of an Aluminum Oxide silicon Carbide Whisker Reinforced Ceramic matrix Composite written by Carlos F. Alonzo and published by . This book was released on 1997 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book R curve Behavior for Silicon Carbide Whisker Reinforced Aluminum Oxide Composites written by Christophe Mangin and published by . This book was released on 1990 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
