Thermomechanical Consolidation of Ti/Al/Cr Composite (Composition: Ti-47Al-2Cr (at %)) Powders

Abstract

The present study aims to develop a process to make ultrafine grained (UFG) Ti-47Al-2Cr (at %) alloy using elemental Ti, Al and Cr powders. The process involves mechanical milling of a mixture of the elemental powders to produce a Ti/Al/Cr composite powder, compaction of the milled powder, and consolidation of the powder compact using hot isostatic pressing (HIP) or powder compact forging. This paper is to give an overview of microstructure and the mechanical properties of the alloy samples obtained using the above processing technique. Inhomogeneous microstructures with high amounts of (α2) Ti3Al phase, along with, elemental Ti, were observed in some samples. An attempt has been made to explain the formation of (α2) Ti3Al, and elemental Ti, in the alloy and the processing conditions appropriate for the specific alloy are also discussed.