Dynamic response of Ti-6.5Al–1Mo–1V–2Zr-0.1B alloy fabricated by wire arc additive manufacturing

Abstract

The metallic component parts fabricated by wire arc additive manufacturing (WAAM) usually present columnar grain structures along the build direction showing anisotropy in both microstructure and mechanical response. In this work, a thin-walled sample is made by the WAAM method using Ti-6.5Al–1Mo–1V–2Zr-0.1B wires, where 0.1 wt% B element is added into the near-α titanium alloy. The microstructure of the as-deposited sample exhibits an equiaxed prior-β grain structure. The dynamic response of the WAAM sample is studied systematically along both scanning direction (OY) and building direction (OZ). The sample exhibits a much low anisotropy in mechanical response at a strain rate of 3000 s−1 along the OY and OZ directions. The differences are less than 1% and 6% along the two directions for the average flow stress and the uniform plastic strain, respectively. A preferred orientation of <0001>α along the loading direction is found after the dynamic compression. The formation mechanism of the crystal preferred orientation is discussed.