The effect of heat treatment on the mechanical properties of Ti-6Al-4V alloy produced by consolidating a high impurity blended powder mixture using a combination of powder compact hot pressing and extrusion

摘要

In this study, a rapid powder consolidation method combining powder compact hot pressing and extrusion was utilized to consolidate relatively cheap, high impurity blended powder mixture Ti-6Al-4V alloy. The purpose of this work was to investigate whether a suitable microstructure deriving from a particular heat treatment balance out or compensate for the presence of high interstitial impurity contents. From mechanical property data attained, it was clear that annealing in high alpha-beta region gave a much better combination of mechanical properties: impact toughness (14 J), yield strength (878 MPa), ultimate tensile strength (1092 MPa), and ductility/plastic strain (6.2%) compared to as-extruded material despite the presence of 0.44 wt% oxygen. Therefore, it can be concluded that optimization of microstructures provides improvement to the fracture related properties and Ti-6Al-4V produced in this way is suitable for less demanding applications. For further enhancement in properties, utilization of low oxygen starting powders is vital.