The effects of V content on the microstructure and mechanical properties of hot rolled TiZr based alloys

摘要

The effects of V content (0-7 wt.%) on the structure and mechanical properties of TiZrAlV alloys were investigated. The phase composition changes as alpha' -> alpha' + (alpha" + beta) -> a" + beta -> beta + (a") -> beta with increased V content from 0 wt.% to 7 wt.%. Specifically, the single beta phase that is impossible to achieve in Ti-V binary alloys was obtained in the TiZrAlV alloy with an increased V content of 7 wt.%. The microstructure of alloys with <1 wt.% V was characterized by martensite filling the original beta grains. Dynamic recrystallization occurred in alloys with >3 wt.% V. With increased V content, the recrystallization volume fraction increased, and changes in the elastic modulus and yield strength exhibited an antiparabolic trend. The alloy with 3 wt.% V had the minimum average elastic modulus (68 GPa) and an average yield strength (690 MPa). With increased V content, the trend of elongation was the reverse of the yield strength. However, the trend of tensile strength remarkably differed from that of the yield strength. The alloy with 3 wt.% V had favorable comprehensive properties: a maximum average elongation (12.7%) and a high average tensile strength (1358 MPa). The strengthening and toughening mechanisms of TiZrAlV alloys were also discussed. (c) 2015 Elsevier B.V. All rights reserved.