Achieving fully-equiaxed fine β-grains in titanium alloy produced by additive manufacturing

The achievement of fine equiaxed beta grain with conventional intragranular (alpha -Ti+beta-Ti) microstructure in additive manufacturing titanium alloy remains a big challenge. We conquer this challenge by synergistically controlling beta-grains during both solidification and subsequent thermal-cycles of laser directed energy deposition (DED), and a solution + quenching heat-treatment. Both the strength and plasticity of heat-treated Ti6A14V3Ni0.05B are superior to those reported new DED titanium alloy and comparable to that of DEDTi6Al4V, because of the fine-equiaxed beta-grains with intragranular Ti+beta-To microstructure. These findings provide new insight into the grain structure control and the composition design of AM titanium alloy.

Automated summary

The achievement of fine equiaxed beta grain with conventional intragranular microstructure in additive manufacturing titanium alloy remains a big challenge. We conquer this challenge by synergistically controlling beta-grains during both solidification and subsequent thermal-cycles of laser directed energy deposition (DED), and a solution + quenching heat-treatment. These findings provide new insight into the grain structure control and the composition design of AM titanium alloy.