Preparation, microstructure and properties of Ti-6Al-4V rods by powder compact extrusion of powder mixture

Abstract

Ti-6Al-4V (wt%) alloy rods were prepared successfully using a low-cost method that combines mixing elemental and master alloy powders and powder compact extrusion. The microstructure and mechanical properties of the rods and the effects of extrusion temperature on them were investigated. The results showed that the microstructure and mechanical properties of the extruded rods were strongly affected by the extrusion temperature. With increasing extrusion temperature from 1200°C to 1300°C and keeping the powder compact holding time unchanged at 2 minutes, the fraction of undissolved V rich particles in the microstructure of the extruded rod decreased substantially to zero, the level of composition homogenization increased dramatically to the highest level, and the UTS and elongation of the extruded rods increased significantly from 886MPa and 1.2% to 1300MPa and 7.1%, respectively. The tensile properties of the Ti-6Al-4V alloy rods produced by powder compact extrusion of the powder mixture are comparable to those of Ti-6Al-4V alloy produced by ingot metallurgy and thermomechanical processing.