Enhanced Strength and Corrosion Resistance of Ti‐13Nb‐12Ta‐10Zr‐4Sn Alloy by Aging Treatment

This work investigates the effect of aging treatment on the mechanical properties and corrosion resistance of Ti‐13Nb‐12Ta‐10Zr‐4Sn (TNTZS) alloy prepared by vacuum arc melting. The as‐cast TNTZS alloy was solution‐treated and aged at 450°C (HT450) and 550°C (HT550). Microstructural characterization revealed significant changes in the phase proportion (in vol%), which transformed from 64% β, 19% α, and 17% α″ in as‐cast condition to 54% β, 13% α, and 33% α″ for HT450 and 55% β, 25% α, and 20% α″ for HT550, respectively. The tensile strength and yield strength increased from 608 and 424 MPa in as‐cast condition to 1192 and 1180 MPa for HT450 and 921 and 819 MPa for HT550, respectively. The strengthening effect is mainly attributed to the increase in martensite α″ phase after aging treatment. HT550 exhibited excellent corrosion resistance, with a reduced corrosion current density and increased passive film resistance. The improved corrosion resistance is owing to the denser lattice structure of β and the formation of a thicker and denser passivation film with smaller interatomic spacing. This work provides a reference for developing high‐strength and corrosion‐resistant titanium alloys.