R. Panza-Giosa, Goodrich Landing Gear, Oakville, ON, Canada; D. Embury, X. Wang, McMaster University, Hamilton, ON, Canada; Z. Wang, University of Toronto, Toronto, ON, Canada

Summary: Mechanical properties of heat treated Ti-5Al-5V-5Mo-3Cr, an attempt to define critical properties of various microstructural features The properties and microstructure of Ti-5Al-5V-5Mo-3Cr were characterized under various stress states after the following heat treatments: 1) beta anneal and air cool; 2) solution heat treatment in the alpha-beta range; 3) solution heat treatment and ageing in the alpha-beta range. For each condition, the damage mechanisms and final fracture modes were evaluated and rationalized on the basis of microstructural features. The true fracture stresses for the various conditions are compared. Beta annealed material exhibits intense localized slip deformation leading to early crack formation and fracture. This mechanism is explained in relation to the presence of fine metastable phase precipitates resulting from the air cool step. Grain size dependence of the yield stress is described in terms of the Hall-Petch relationship. Authors: Roque Panza-Giosa – Manager, Materials and Process Technology, Goodrich Landing Gear, Oakville, Canada Dr. David Embury - Distinguished Professor, McMaster University, Hamilton, Canada Dr. Zhirui Wang - Professor Materials Science and Engineering, University of Toronto, Toronto, Canada Dr. Xian Wang - Associate Researcher, McMaster University, Hamilton, Canada