Review of Ti-6Al-4 V alloy processing, microstructure, and mechanical properties from powder metallurgy to additive manufacturing for engineering applications

Ti-6Al-4 V, a dual-phase (α + β) titanium alloy, has been widely used in aerospace, marine, and biomedical industries due to its outstanding properties, including a high strength-to-weight ratio, corrosion resistance, and improved mechanical performance. Because of these advantages, this alloy attracts considerable research attention, especially in enhancing its processing methods, microstructure, and mechanical performance. This review focuses on the processing of Ti-6Al-4 V through conventional powder metallurgy techniques such as metal injection moulding, vacuum pressureless sintering, microwave sintering and spark plasma sintering. The influence of processing parameters on densification, microstructural evolution and mechanical properties is discussed. This review examines advanced manufacturing methods, particularly additive manufacturing techniques such as selective laser melting, electron beam melting, and direct energy deposition, which enable near-net-shape fabrication and improved microstructural control. The role of post-processing, particularly heat treatment, in modifying the microstructure and enhancing the alloy’s mechanical performance is also considered. Overall, this review summarises the relationship between the processing methods, densification, microstructure evolution, and mechanical performance of the Ti-6Al-4 V alloy, providing useful insights for the development and application of this alloy in high-performance engineering fields.