Optimization Mechanism of Mechanical Properties in TC4 Titanium Alloy via Si/Y Co-doping

Titanium alloys, leveraging advantages such as high strength and low density, are widely applied in aerospace, automotive, medical, and other fields, but they face challenges including significant processing difficulty, performance degradation during long-term high-temperature service, and insufficient wear resistance. In the present work, the effects of Si and Y co-doping on the microstructure and mechanical properties of Ti-6Al-4V alloys were investigated. The experimental results showed that the addition of Si and Y promoted the formation of β-phase，facilitated the nucleation of yttrium oxides at dimples, and altered the tensile fracture mode. Mechanical property tests of the alloy show that Si-Y doping exerts a significant optimization effect on the strength and toughness of the Ti64 alloy. It not only increases the compressive strength from the original 528 MPa to 711 MPa, but also raises the elongation from 10.1% to 13.1%, which not only verifies the synergistic enhancement effect of this doping scheme on strength and toughness, but also provides key support for the regulation of alloy properties.