Segregation and Convection Studies in gamma-TiA1 Alloy Solidification

该建议用于工业上重要的TiAl合金铸件的评估。这种合金的一种工程形式，被称为y-TiAl，目前处于研究阶段，预计将在不久的将来被引入航空航天工程和其他尖端应用。该合金具有与Galn合金相似的两个属性，这被认为是导致熔体中偏析增强的原因：(1)元素密度的差异；(2)元素熔化温度的不同。TiAl和Galn的研究结果将有助于更好地理解热驱动和固驱动金属合金熔体中的偏析和流动物理。本研究的结果可以提供有用的实验结果，将刺激新的流体力学模型的发展，以及调整工业加工炉的设计。该合作研究项目解决了自然对流池中流体物理和化学偏析研究的基本问题，结合工业相关的垂直Bridgman结晶，包括冶金表征和拉伸测试，将提高对TiAl合金铸件制造要求的理解。该研究项目理论与实验相结合，将为航空航天工业和铝制造业提供有价值的研究成果。

9700206 Koster This proposal is for the assessment of industrially important TiAl alloy castings. One engineering form of that alloy, known as y-TiAl, currently in a research stage, is expected to be introduced in the near future to aerospace engineering and other cutting edge applications. That alloy has two attributes similar to the Galn, which are thought to contribute to the enhanced segregation in the melt: (1) the difference in density of the elements, and (2) the different melting temperatures of the elements. The research results from both TiAl and Galn will contribute to a better understanding of the physics of segregation and flow in thermally and solutally driven metallic alloy melts. The outcomes of this research could provide useful experimental results that will spur the development of new fluid mechanical models as well as adjusting designs for industrial processing furnaces. This collaborative research project addresses fundamental issues on fluid physics and chemical segregation study in the natural convection cell, combined with the industrially relevant vertical Bridgman crystallization, including metallurgical characterization and tensile testing, will improve the understanding of manufacturing requirements for TiAl alloy castings. The research project has a balance between theory and experiment, and will provide valuable findings for the aerospace industry as well as the aluminum manufacturing industry.