Mechanical Behaviour and Microstructural Evolution of Ti-6al-1mo-1v-2zr-2cr-1fe Alloy Subjected to Hot Compression Deformation

Abstract

A new titanium alloy with chemical composition of Ti-6Al-1Mo-1V-2Zr-2Cr-1Fe (wt.%) is designed and produced. The hot deformation behavior, microstructural evolution and texture evolution of the alloy after solution treatment are investigated in this paper. Firstly, the constitutive equation of solution-treated Ti-6Al-1Mo-1V-2Zr-2Cr-1Fe alloy with the consideration of strain compensation is obtained based on compressive test at the temperatures of 950-1100 °C and the strain rates of 0.01-10 s-1, which can be used to describe the flow behaviour at elevated temperatures. According to the corresponding constitutive equation, the flow stress of solution-treated alloy is accurately predicted, which is further verified by the experimental data. Furthermore, discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX) are observed in the microstructures of the deformed alloys, where deformation temperature and strain rate have a significant effect on DDRX and CDRX processes of solution-treated Ti-6Al-1Mo-1V-2Zr-2Cr-1Fe alloy. Moreover, plastic deformation and dynamic recrystallization have a comprehensive influence on the texture evolution of solution-treated Ti-6Al-1Mo-1V-2Zr-2Cr-1Fe alloy. ηbcc-fiber textures of {100}<001> and {110}<001>, εbcc-fiber texture of {112}<111> and ξbcc-fiber texture of {110}<112> are the main texture compositions of the deformed  samples, where all of the deformed samples exhibit a strong {100}<001> texture.

Keywords: Titanium alloy, Hot deformation, Constitutive equation, Microstructure, Dynamic recrystallization