Tensile properties of gas tungsten arc weldments in commercially pure titanium,Ti–6Al–4V and Ti–15V–3Al–3Sn–3Cr alloys at different strain rates

Abstract

The influence of microstructure and strain rate on the mechanical behaviour of three titanium alloys having applications in aerospace, namely, commercially pure titanium (α phase), Ti–6Al–4V (α + β phases) and Ti– 15V–3Cr–3Sn–3Al (β phase) is investigated for both the parent metals and their gas tungsten arc weldments. The results indicate that the tensile strengths of the three as received titanium alloys and their weldments increase with increasing strain rate. However, their elongations decrease with increasing strain rate. The as received Ti–6Al–4V alloy and its weldment, with a mixed α and β phase microstructure, have the maximum strength and microhardness. Commercial purity titanium metal and its weldment exhibit the minimum strength and microhardness. The tough Ti–15V–3Cr–3Sn–3Al alloy and its weldment, having a fully β phase microstructure, appear to have optimum strength and microhardness. The tensile properties of all three titanium alloy weldments are inferior to those of the as received metals.