Intensification of preferred orientation in the additive manufactured Ti-6Al-4V alloy after heat treatment

The ductility of laser powder bed fusion (LPBF) Ti-6Al-4V alloy is generally low because the microstructure is α′-martensite. Heat treatment is widely used to improve the microstructure and ductility, though the preferred orientation after heat treatment is undetermined to date. This study identified the influences of heat treatment temperature on the preferred orientation of LPBF Ti-6Al-4V. The results showed a weak { 112¯0 } α′ texture along the building direction in the as-built Ti-6Al-4V. After 750 °C heat treatment, α′-martensite was transformed to α + β phases. The { 112¯0 } α preferred orientation gradually intensified as the heat treatment temperature was increased, as shown by X-ray diffraction and electron backscatter diffraction. After 950 °C heat treatment, { 112¯0 } α was mostly aligned with the building direction.