Effects of hot extrusion on the microstructure and properties of Ti-6A1-4V titanium alloy

Experiments were performed to investigate the effect of extrusion ratio and temperature on the microstructure, texture and mechanical properties of Ti-6A1-4V titanium alloy. When the extrusion temperature is in the range of 150 to 350℃ above the phase transition temperature (T~) and the extrusion ratio (A) is in the range of 25 to 85, dynamic recrystallization has completed and there is a uniform Widmanst~tten structure in the extruded section. Increasing the extrusion ratio and decreasing the extrusion temperature can refine grains in the extruded section. When the extrusion ratio is low at 25, the texture strength is weak and random distributed. With the extrusion ratio increasing, the texture strengthens and is inclined to evolve into the (1219) fiber texture. The perfect (1219) fiber texture is achieved when the extrusion ratio is 85. The comprehensive performance of the extruded section obtained under different extrusion conditions is stable because of the combined effect of texture and grain refinement, the difference in strength is less than 35 MPa, and the differences in elongation and necking rate are all less than 3%.