U.S.-Germany Cooperative Research on Stress-Induced Transformation and Crack Growth in Partially-Stabilized Zirconium Oxide-Based Ceramics

该奖项将支持陶瓷领域的合作研究 凯斯西储大学的亚瑟豪雅博士 和Rolf Steinbrech博士，Institut fur Reaktorwerkstoffe， KFA，Julich，德国。 该项目的目标是 应力诱发相变和裂纹扩展研究 氧化锆。 含氧化锆陶瓷中的相变增韧， 一直是科学和技术领域的热点 在过去的十年里，鉴于潜在的工业 这些材料在苛刻条件下的应用 疲劳和高温暴露。 的一个主要 在这一时期的研究结果一直是“抵抗- “tance-curve”（R-曲线）行为。在这个项目中，单调 低周疲劳、环境对自然裂纹的影响 室温下的行为和预开裂（“远场”） 将研究应力诱导的转变。断裂 力学测试将主要在Julich进行。 的 克利夫兰的工作将强调微观结构特征， 断裂力学试验样品的化和 试验后确定转换区， 豪雅博士的专长 此外，现场测试将 在缺乏的情况下， 微裂纹，使用低电压SEM，光学干涉， 和显微拉曼光谱。 该项目将受益于 两者之间过去成功合作的历史 研究人员和他们在骨折方面的互补专长 力学和微观结构表征。

This award will support collaborative research in ceramics between Dr. Arthur Heuer, Case Western Reserve University, and Dr. Rolf Steinbrech, Institut fur Reaktorwerkstoffe, KFA, Julich, Germany. The objective of the project is to investigate stress-induced transformation and crack growth in zirconia. Transformation toughening in zirconia-containing ceramics has been an area of intense scientific and technological interest during the past decade, in view of the potential industrial applications of these materials in demanding conditions of fatigue and high temperature exposure. One of the major findings during this period has been the importance of "resis- tance-curve" (R-curve) behavior. In this project, monotonic and low cycle fatigue, environmental effects on natural crack behavior at room temperature, and pre-cracking ("far-field") stress-induced transformation will be studied. The fracture mechanics testing will largely be conducted in Julich. The work in Cleveland will emphasize microstructural characteri- zation of the fracture mechanics test specimens and the determination of transformation zones after testing, both specialties of Dr. Heuer. In addition, in situ tests will be carried out involving transformation in the absence of microcracking, using low voltage SEM, optical interferometry, and micro-Raman spectroscopy. The project will benefit from the past history of successful collaboration between the two investigators and their complementary expertise in fracture mechanics and microstructural characterization.