Effect of annealing temperature on microstructure and mechanical properties of a Ti-18Zr-12.5Nb-2Sn (at.%) alloy

Abstract

In this study, the effect of annealing temperature on microstructure and mechanical properties of a Ti-18Zr-12.5Nb-2Sn (at.%) alloy was investigated by using optical microscopy (OM), X-ray diffraction (XRD) measurement and tensile test. The cold-rolled plate was annealed at temperatures between 773 K and 1173 K. Recrystallization occurred in the specimen annealed at 873 K. Grain size increased from 8 mu m to 80 mu m with increasing temperature from 873 K to 1173 K. The ultimate tensile strength decreased from 1590 MPa to 806 MPa with increasing annealing temperature from 773 K to 973 K, and then showed similar value in the specimens annealed at temperatures from 973 K to 1173 K. The fracture strain increased from 3.8% to 41.0% with increasing annealing temperature from 773 K to 1173 K due to the recovery and recrystallization. The recovery strain increased with increasing of annealing temperature attributed to the evolution of recrystallization texture.