High-strength and low-modulus β-type Si-containing titanium alloy, preparation method therefor and use thereof

A preparation method for a P Si-containing titanium alloy, comprising the steps of:

• (1) preparing alloy components with, in atomic percentage, 60-70% of Ti, 10-20% of Nb, 5-15% of Zr, 1-10% of Ta and 1-5% of Si and using sponge titanium, sponge zirconium, a tantalum-niobium alloy and silicon as raw materials;
• (2) smelting the alloy components prepared in step (1) to obtain a solidified ingot;
• (3) subjecting the solidified ingot obtained in step (2) to plastic deformation with a deformation temperature of 800-900° C. and a deformation rate of 60-80%, and water-quenched to room temperature to obtain a plasticly deformed ingot, wherein the plastic deformation in the step (3) adopts any one of hot rolling, hot forging, and hot extrusion;
• (4) heating the plasticly deformed ingot in step (3) to a recrystallization temperature of 900° C., maintaining the recrystallization temperature for 1-4 hr to obtain a recrystallized ingot, and carrying out an annealing treatment and air-cooling on the recrystallized ingot to room temperature to obtain the β Si-containing titanium alloy.