Effect of Vacuum Heat Treatment on the Microstructure and Tribological Property of Ti–6Al–4V Alloy with Cu Coating

The effect of vacuum heat treatment on the interface microstructure and tribological property of Cu‐coated Ti–6Al–4V alloy is investigated herein. After the vacuum heat treatment process, a diffusion layer is formed at the interface between the Cu coating and the Ti–6Al–4V substrate. The formed intermetallic compounds at the interface between the Ti–6Al–4V substrate and Cu coating are CuTi₂, CuTi, Cu₄Ti₃, and β‐Cu₄Ti. The activation energy of intermetallic compound growth in the diffusion zone of Cu‐coated Ti–6Al–4V is 126.0 kJ mol⁻¹, and the pre‐exponential factor is 0.1 m² s⁻¹. The tribological properties of the Cu‐coated Ti–6Al–4V alloy are best when subjected to diffusion treatment at 700 °C for 300 min, with weight loss reduced by 58.2% compared to the Ti–6Al–4V alloy. The wear resistance of the Ti–6Al–4V alloy can be enhanced by Cu coating and vacuum diffusion heat treatment, and the formation of the Cu–Ti intermetallic compound contributes to this improvement. These findings offer new insights for further advancements in the tribological properties of titanium alloys.