Effects of titanium concentration on microstructure and mechanical properties of high-purity vanadium alloys

Abstract

Effects of Ti concentration on microstructure and mechanical properties of high-purity V-4Cr-xTi alloys have been studied by means of scanning electron microscopy, transmission electron microscopy, Vickers hardness and tensile tests. Results show that precipitation occurs with 1 wt% Ti addition and above, whose diameter gradually increases as Ti concentration rises. Vickers hardness and tensile strength increase with increasing Ti concentration. Moreover, strengthening mechanisms consisting of solid solution strengthening (σSS), grain boundary strengthening (σGB), and precipitation strengthening (σP) are theoretically estimated. The strength contribution sequence is σSS > σGB > σP. Solid solution strengthening from Ti increases with increasing Ti concentration, and precipitation strengthening is not significantly dependent on Ti concentration. Additionally, 1 wt% Ti is probably sufficient to scavenge the interstitial impurities and provide comparable precipitation strengthening with V-4Cr-4Ti alloy.

Keywords

• High-purity vanadium alloy
• Ti concentration
• Precipitation
• Tensile properties
• Strengthening mechanisms