Tensile and Compression Testing of Single-Crystal Gamma Ti-55.5 Al

Abstract

ABSTRACTThe orientation and temperature dependence of the flow strength of γ-TiAl is being measured to promote a fundamental understanding of the deformation mechanisms that are active in this alloy. High quality single crystals of γ- Ti-55.5 Al have been grown using an optical float zone furnace, which allows for crystal seeding and provides a containerless growth environment. These crystals have been oriented using back reflection Laue and TEM and cut into microsample tensile specimens by electric discharge machining. The microsample testing technique developed at Johns Hopkins [1] is being utilized to measure the orientation, temperature and tension/compression dependence of the flow strength of TiAl. An outline of the microsample testing techniques that have been developed for this study and preliminary results follow in this paper.