Investigation on the microstructure and mechanical properties of gum metal TNTZO titanium alloy prepared by selective laser melting

Abstract

In this study, a high-dense multi-functional gum metal Ti36Nb2Ta2.7Zr0.3O (mass%, TNTZO) alloy was successfully produced using selective laser melting (SLM). The as-built components exhibited epitaxially grown β grains with a slight deviation from the building direction, resulting in a cubic-like texture where (001)β was oriented along the building direction. Additionally, nanoscale ω precipitates were found embedded in the β matrix. The uniaxial tensile tests revealed that the as-built TNTZO alloy had repeatable strength with a yield strength of 756 MPa. Dislocation slip was the dominant mechanism responsible for the deformation of the as-built TNTZO alloy, with no phase transformation or deformation twin observed. The interaction between the ω variants with the dislocations during plastic deformation led to the formation of “ω-free channels” due to the different orientation relationship of ω variants with β matrix. The post-mortem analysis revealed that ductile fracture is the dominant fracture mode.