The Contents Effect of Primary Α Phase and Secondary Α Phase on Microstructures Evolution and Mechanical Properties of Ti-5al-5mo-5v-1cr-1fe Alloy

Abstract

The contents effect of primary α phase (αp) and secondary α phase (αs) on the microstructures evolution and mechanical properties of as-forged Ti-5Al-5Mo-5V-1Cr-1Fe alloy were investigated. The results showed that the contents of αp phase in alloys after four different heat treatment regimes were 32.8%, 34.3%, 33.3% and 46.0%, respectively, and the contents of αs phase were 4.8%, 8.7%, 13.6% and 12.6%, respectively. The highest elongation was reached when the contents of αp phase and αs phase were 32.8% and 4.8%, respectively, and the highest strengths were obtained when the contents of αp phase and αs phase were 33.3% and 13.6%, respectively. The promotion or inhibition on dynamic recrystallization in αp phase and αs phase with the increasing of contents of αp phase and αs phase, which dominated the morphologies and sizes of αp phase and αs phase. The coexistence of αp phase and αs phase with different sizes caused by dynamic recrystallization, which affected the elongation of the alloy and the dispersion strengthening effect of αs phase. The textures evolution of αp phase and αs phase were dominated by the contents of αp phase and αs phase. Compared with the αp phase, the variation of contents of the αs phase had greater effect on microstructures evolution and mechanical properties of the alloy.

Keywords: As-forged Ti-5Al-5Mo-5V-1Cr-1Fe alloy, The content of primary α phase, The content of secondary α phase, Microstructures evolution, Mechanical properties