Influence of heat treatment on welding process of electron beam welded joint of Ti6Al4V parts manufactured via laser powder bed fusion

The present work was conducted to determine the effect of welding as-printed selective laser melting samples and fabricated samples welded with stress-relieved conditions. The research aimed to study the influence of heat treatment on welding parameters and weldability. Additive manufacturing by selective laser melting can achieve near-net shape and complex structure. It has been widely used in manufacturing aerospace components, in the automobile sector and other fields. Ti6Al4V is the most commonly used and researched alloy in additive-manufactured alloys. The microstructure of Ti-6Al-4V is diverse and consists of acicular martensite α’ phase with prior β grains. The results showed the formation of α-phase around the β grains in the heat-affected zone where the temperature reached above the T0 [<893°C], the β-phase recrystallization during the welding process. The primary α-phase develops and forms along the grain boundaries and was more prominent in the stress-relieved specimens. The microhardness decreases in the weld of stress relieved condition compared to weld as-printed condition.