Properties of Yttria-tetragonal Zirconia Polycrystal (Y-TZP) Materials After Long-term Exposure to Elevated Temperatures. Final Report PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Properties of Yttria-tetragonal Zirconia Polycrystal (Y-TZP) Materials After Long-term Exposure to Elevated Temperatures. Final Report PDF full book. Access full book title Properties of Yttria-tetragonal Zirconia Polycrystal (Y-TZP) Materials After Long-term Exposure to Elevated Temperatures. Final Report by . Download full books in PDF and EPUB format.
Author: Publisher: ISBN: Category : Languages : en Pages : 25
Book Description
Seven commercially available yttria-tetragonal zirconia polycrystal (Y-TZP) materials were evaluated. Room temperature properties were measured before and after heat treatments at 1000C. Microstructure and phase stability were also examined. In all but one case, the Y-TZPs showed very little change in room temperature properties after long times at this temperature. Results show that pressure-assisted processing greatly improves the strength by reducing porosity and keeping the grain size extremely fine, but this reduces the toughness because finer grains are more difficult to transform. In addition, a small amount of cubic zirconia appears to enhance the toughness of fine-grained Y-TZP while maintaining good strength. During processing, a small amount of cubic zirconia is formed and allowed to grow. This creates regions poor in yttria which can transform spontaneously in the presence of a crack-tip stress field.
Author: Publisher: ISBN: Category : Languages : en Pages : 25
Book Description
Seven commercially available yttria-tetragonal zirconia polycrystal (Y-TZP) materials were evaluated. Room temperature properties were measured before and after heat treatments at 1000C. Microstructure and phase stability were also examined. In all but one case, the Y-TZPs showed very little change in room temperature properties after long times at this temperature. Results show that pressure-assisted processing greatly improves the strength by reducing porosity and keeping the grain size extremely fine, but this reduces the toughness because finer grains are more difficult to transform. In addition, a small amount of cubic zirconia appears to enhance the toughness of fine-grained Y-TZP while maintaining good strength. During processing, a small amount of cubic zirconia is formed and allowed to grow. This creates regions poor in yttria which can transform spontaneously in the presence of a crack-tip stress field.
Author: Jeffrey J. Swab Publisher: ISBN: Category : Languages : en Pages : 28
Book Description
Due to an unusual combination of high strength and toughness, tetragonal zirconia polycrystal (TZP) materials are candidates for use in advanced heat engines. The properties of these materials stem from the stress-assisted transformation of metastable tetragonal zirconia particles. However, after long times at elevated temperatures, this class of materials is susceptible to properties degradation due to the undesirable transformation of tetragonal zirconia to monoclinic zirconia upon cooling. Accordingly, a task was initiated to examine the extent and magnitude of this phenomenon's effect on the properties. Seven commercially available yttria-tetragonal polycrystal (Y-TZP) materials were evaluated. Room temperature properties were measured before and after heat treatments at 1000 C. Microstructure and phase stability were also examined. In all but one case, the Y-TZPs showed very little change in room temperature properties after long times at this temperature. Keywords: Ceramic materials, Zirconia, Zirconium compounds, Heat engines, Mechanical properties, High temperature, High strength. (jes).
Author: Advisory Committee on Technology and Society Publisher: National Academies Press ISBN: 9780309037860 Category : Social Science Languages : en Pages : 1298
Book Description
Cities and Their Vital Systems asks basic questions about the longevity, utility, and nature of urban infrastructures; analyzes how they grow, interact, and change; and asks how, when, and at what cost they should be replaced. Among the topics discussed are problems arising from increasing air travel and airport congestion; the adequacy of water supplies and waste treatment; the impact of new technologies on construction; urban real estate values; and the field of "telematics," the combination of computers and telecommunications that makes money machines and national newspapers possible.
Author: Publisher: ISBN: Category : Languages : en Pages : 19
Book Description
A commercially available tetragonal zirconia polycrystal ceramic was examined for potential use in advanced engines. Room temperature strength and toughness were determined, as well as the static fatigue life between 800 deg C and 1200 deg C. All of these properties were determined before and after a 100 hour exposure at 1000 deg C. The room temperature flexure strength was 1838 MPa before exposure and it decreased 23% after exposure. The toughness did not change with the exposure. Static fatigue testing revealed that fracture below 1100 deg C was due to the cracks created during machining. At 1100 deg C and higher slow crack growth became the dominant failure mechanism. Overall, the high temperature static fatigue life is better than yttria tetragonal zirconia polycrystal materials without Alumina but it still does not meet the strength at temperature requirements for use in advanced engines.
Author: Mel M. Schwartz Publisher: McGraw-Hill Companies ISBN: Category : Science Languages : en Pages : 584
Book Description
Aims to bridge the gap between the technical and commercial literature available on structural ceramics, by presenting coverage of processing techniques, classes of ceramics, current mechanical property data, materials manufacture and parts fabrication and assembly methods.
Author: 
Author: 
Author: Jeffrey J. Swab
Author: 
Author: 
Author: Advisory Committee on Technology and Society
Author: 
Author: 
Author: 
Author: Mel M. Schwartz
Author: