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.
