The Design of Hot-Isostatic Pressing Schemes for Ti-5Al-5Mo-5V-3Cr and their Effects on Microstructure and Fatigue Properties

The design of hot-isostatic pressing schemes for Ti-5Al-5Mo-5V-3Cr and their effects on microstructure and fatigue properties Nataliya Perevoshchikova, Christopher Hutchinson, Xinhua Wu Department of Materials Engineering , Monash University, Melbourne, Australia Manufacturing of Ti structural components via powder processing requires consideration of powder quality, processing technology and processing condition. This paper provides an overview on net shape HIPping (hot-isostatic pressing) of Ti-5Al-5Mo-5V-3Cr (Ti-5553) powders for load bearing components. The design and effects of different thermomechanical HIPping schemes on mechanical properties of powder HIPped Ti-alloys will be reported and discussed. The volume fraction of phase in the alloy at the HIPping temperature plays a key role on the bonding mechanism of powder particles. A higher volume fraction of phase at the HIPping temperature appears to lead to more extensive recrystallisation at powder boundaries and is correlated with improved resistance to fatigue of the HIPped material. This is demonstrated by microstructure and mechanical properties of Ti-5553 powders HIPed under a range of conditions. Computation thermodynamics was used to calculate the volume fraction of phase in Ti-5553 at different temperatures and experiments have been carried to HIP the material at selected temperatures/conditions in order to demonstrate the effect of phase volume fraction on the recrystallization of power particle boundaries. The resulting fatigue properties have been compared with cast and wrought material.