Effect of electropulsing on anisotropy in strength of laser metal deposited Ti−6Al−4V alloy

Abstract

The effect of electropulsing treatment on microstructure and mechanical strength of laser metal deposited Ti−6Al−4V alloy was investigated in order to eliminate the anisotropy in strength of laser metal deposited Ti−6Al−4V alloy by tensile tests, optical microscopy, scanning electron microscopy, electron back-scattered diffraction analyses and transmission electron microscopy. With increasing applied voltages from 0 to 130 V, the evolution of microstructure within columnar β grains followed the sequence of α′ martensite → colony α structure → basket-weave α structure. The electropulsing treated at 130 V weakened the texture of martensite within β grains. The as-built Ti−6Al−4V alloy showed an anisotropy in yield strength (6.2%). After processing at 130 V, the anisotropy in yield strength was reduced to 0.6%, which was attributed to the almost equivalent distribution of Schmid factor in the samples deformed along different orientations.