Effect of Vanadium Contents on Microstructure and Mechanical Properties of Ti-6Al-xV Components Produced by Wire plus Arc Additive Manufacturing

Wire + Arc Additive Manufacturing (WAAM) is an advanced manufacturing technology by inexpensive Gas Tungsten Arc Welding (GTAW) technology. Key microstructural features of the as-built WAAM alloy include large columnar beta grains, grain boundary alpha colonies, and Heat Affected Zone (HAZ) banding, which generally leads to low ductility and anisotropy. In this study, Ti-6Al-xV (x = 0, 2, 4) alloys were prepared by WAAM, the effects of vanadium content on the microstructure, tensile properties and impact toughness were investigated. Irregular-shaped, plate-like features without columnar grains and HAZ banding were obtained in Ti-6Al alloy. Columnar grains were observed in Ti-6Al-2V alloy, and the grain size was further enlarged to more than ten millimeters by 4 mass% vanadium addition. With the increasing of vanadium content, a monotonic increase in yield strength and ultimate tensile strength can be observed, while the fracture strain and impact toughness changed in the opposite trend Ti-6Al and Ti-6Al-2V alloy exhibited better matching of strength, ductility and impact toughness compared with Ti-6Al-4V alloy.

Automated summary

The study investigated the effects of vanadium content on the microstructure, tensile properties and impact toughness of Ti-6Al-xV alloys prepared by Wire + Arc Additive Manufacturing (WAAM). Ti-6Al and Ti-6Al-2V alloys exhibited better matching of strength, ductility and impact toughness compared with Ti-6Al-4V alloy, with a monotonic increase in yield strength and ultimate tensile strength observed with increasing vanadium content.