Study on the microstructure and properties of Ti6Al4V lattice structure formed by selective laser melting

This study employed selective laser melting technology to fabricate four lattice structures (body centered cubic, body centered cubic with simple cubic, face centered cubic, and face centered cubic with simple cubic) of Ti6Al4V, and systematically compared their porosity, phase composition, microstructure, and properties. The research results showed that the actual porosity of all structures was lower than the theoretical design value. All structures primarily consisted of acicular α′ martensite with a small amount of residual β phase. The Body centered cubic structure exhibited the shortest acicular flat noodles and the most uniform microstructure; the Body centered cubic with simple cubic structure had hole defects at the nodes. The Face centered cubic with simple cubic structure exhibited the highest tensile strength, while the Body centered cubic structure had the lowest tensile strength; the Face centered cubic with simple cubic structure had the best compressive properties. The addition of the simple cubic structure suppressed excessive bending of the oblique struts and promoted a partial transition from bending to tensile dominant mechanism, thereby improving the ductility and collapse resistance of the structure; the addition of the simple cubic structure significantly enhanced the impact resistance of the formed parts.