Development and characterisation of low-cost powder metallurgy Ti–Cu–Fe alloys

Abstract

The high cost of Ti alloys is still a primary hindering factor for their wider adoption in different engineering sectors in which they would bring significant benefits. This study analysed the simultaneous addition of cheap alloying elements (i.e. Cu and Fe) aiming to quantify the properties of new low-cost ternary Ti–Cu–Fe alloys obtained via powder metallurgy. It is found that, the amount of alloying elements decreases the compressibility of the powder blends but similar relative density values to those of other powder metallurgy Ti alloys can be achieved. The addition of Cu and Fe leads to the creation of alloys with a lamellar microstructure whose features such as prior β grain size, morphology, interlamellar spacing, and formation of a eutectoid substructure, are determined by the specific chemistry of the alloy. Consequently, the deformation and failure of the sintered ternary Ti–xCu–xFe alloys is governed by the same mechanism but the strength, hardness, ductility, and strain hardening rate are alloy dependent.