Hot Compressive Deformation Behavior of TIMETAL® 54M Alloy

Ti-5Al-4V-0.75Mo-0.5Fe alloy (Ti-54M) is a new alloy developed at TIMET. This alloy exhibits superior machinability in most of machining conditions and strength comparable to that of Ti-6Al-4V. Preliminary tests indicated that compressive flow stresses of the alloy were 20~50% lower than that of mill-annealed Ti-6Al-4V under similar test conditions, which is believed to be one of contributors to its superior machinability. In this work, hot compression tests have been performed isothermally using cylindrical samples on Ti-54M with equi-axed (α-β) microstructure, within a temperature range of 1450ºF -1750ºF and a strain rate of 0.001/s - 1/s. The apparent differences in flow curves obtained were analyzed.  Ti-6Al-4V and Ti-6Al-4V ELI were also included in the investigation.  Dependence of flow stress to temperature, strain rate and alloy composition will be presented and discussed.