Microstructural Evolution and Property Response of SLM‐Fabricated Ti6Al4V–0.5Cu Alloy Under Different Annealing Temperatures

This work investigates the effects of different annealing schedules on the microstructure, mechanical properties, and corrosion resistance of Ti6Al4V and Ti6Al4V–0.5Cu alloys fabricated by selective laser melting (SLM). At the same annealing temperature, no significant differences were observed in the microstructural characteristics between the Ti6Al4V and Ti6Al4V–0.5Cu alloys. At annealing temperatures of 780, 980, and 1080 °C, both alloys exhibited similar microstructural evolution. Initially, at 780 °C, the microstructure was predominantly composed of α′/α martensite, which is similar to the corresponding as‐deposited microstructure. With increasing temperature to 980 °C, the microstructure transformed into a mixture of needle‐like α′/α and lath‐shaped β phases. Ultimately, at 1080 °C, a basket‐like α + β dual‐phase microstructure was formed. Both alloys exhibited superior mechanical performance after annealing at 780 and 980 °C. However, the Ti6Al4V–0.5Cu alloy experienced a significant reduction in tensile ductility when annealed at 1080 °C. The Ti6Al4V–0.5Cu alloy exhibited the best corrosion resistance after annealing at 980 °C. A comprehensive analysis indicates that annealing at 980 °C provides the optimal balance of hardness, tensile strength, ductility, and corrosion resistance for the SLM‐fabricated Ti6Al4V–0.5Cu alloy, representing the most effective heat treatment condition.