Effect of heat treatment on room temperature tensile properties and fracture toughness of a new near beta titanium alloy-Ti-B19

摘要

Ti-B19 alloy is a new near beta Titanjum alloy that underdeveloped by Northwest Institute for Nonferrous Metal Research. It belongs to Ti-Al-Mo-V-Cr-Zr alloy system. Its beta stable coefficient is 1.38, and its beta / alpha beta transformation temperature is 780 deg C- 790 deg C. The effect of heat treatment temperature on room temperature (RT) tensile properties and fracture toughness of Ti-B19 alloy was investigated in the present paper. The results indicated that the microstructure and fracture toughness is strongly dependent on the heat treatment temperature. The fracture toughness is increased with the solution treatment and aging treatment temperature increase, and the size of needle-like alpha _s (second alpha phase) also growing with the aging temperature increase. When the solution treatment temperature is above to the beta / alpha + beta transformation temperature, the tensile properties are not changed greatly with the solution treatment temperature, except the area reduction. At the same solution treatment condition, the tensile strength decreased greatly and the area reduction increased with the aging temperature increase, but the elongation changing is not very greatly.