U.S.-Korea Cooperative Research on Properties, Transforma- tion Characteristics and Shape Memory Behavior of Grain Re- fined Copper-Zinc-Aluminum Alloys

该提案要求允许伊利诺伊大学冶金学教授C.M.Wayman博士与韩国先进科学技术研究所精密金属研究实验室主任Myung-Chul Shin博士开展为期24个月的合作研究计划，研究细化铜锌铝合金的性能、相变特征和形状记忆行为。这些合金通常是黄铜，按重量计算，铜的含量约为70%，铝的含量为2-8%。它们展示了形状记忆效应，通过形状记忆效应，在较低温度下变形的合金在加热到较高温度时完全恢复其初始未变形形状。这项研究将涉及应用细化技术，如掺锆，以减小晶粒度，从而提高成形性和抗疲劳性能。将使用透射电子显微镜和分析电子显微镜来检查颗粒内和晶界上可能含有丰富的锆的第二相颗粒，而颗粒的化学成分将通过分析电子显微镜微观分析来确定。颗粒的凝聚度、应变场和其他机械方面将使用透射电子显微镜来确定。宏观方面的研究将包括表征合金的晶粒度与疲劳，转变温度，以及形状记忆的程度，在细化的晶粒合金。这项研究之所以重要，是因为形状记忆合金在控制、紧固件、电子系统、医疗假肢、致动器以及交通、计算机、机械、农业、能源、建筑和其他制造集团的其他设备中的应用具有广泛的兴趣。该项目与美韩合作科学计划的目标相关，该计划旨在通过交流科学信息、想法、技能和技术以及通过在互利问题上的合作来提高美国和韩国科学家和工程师之间的合作水平。美国和韩国的合作者都是备受尊敬的科学家，在该提案领域拥有丰富的研究经验和富有成效的出版记录。

This proposal requests funds to permit Dr. C. M. Wayman, Professor of Metallurgy, University of Illinois, to pursue with Dr. Myung-Chul Shin, Head, Precision Metals Research Laboratory, Korea Advanced Institute of Science and Technology, for a period of 24 months, a program of cooperative research on the properties, transformation characteristics, and shape memory behavior of grain-refined copper-zinc-aluminum alloys. These alloys are typically brasses, containing about 70% copper, by weight, and 2-8% aluminum. They demonstrate the shape memory effect through which an alloy deformed at some lower temperature completely recovers its initial undeformed shape upon heating to a higher temperature. The research will involve the application of grain refinement techniques such as zirconium doping to reduce grain size so as to improve formability and resistance to fatigue. Transmission and analytical electron microscopy will be used to examine presumably zirconium-rich second phase particles within the grains and along grain boundaries, while the chemical composition of the particles will be determined by analytical electron microscopy microanalysis. The degree of coherency, strain fields, and other mechanical aspects of the particles will be determined using transmission electron microscopy. Macroscopic aspects of the research will include characterization of the alloys in terms of grain size versus fatigue, transformation temperatures, and the extent of shape memory in the grain refined alloys. This research is important because of the broad range of interest in the applications of shape memory alloys to controls, fasteners, electronic systems, medical prosthetics, actuators, and other devices for transportation, computers, machinery, agriculture, energy, building, and other manufacturing groups. This project is relevant to the objectives of the U.S.-Korea Cooperative Science Program which seeks to increase the level of cooperation between U.S. and Korean scientists and engineers through the exchange of scientific information, ideas, skills, and techniques and through collaboration on problems of mutual benefit. The U.S. and Korean collaborators are highly respected scientists with extensive research experience and productive publication records in the field of the proposal.