Research on Hot Deformation Behavior of Ti-5Al-5Mo-5V-1Cr-1Fe Titanium Alloy with Basket-Weave Microstructure

Abstract

The hot deformation behavior of Ti-5Al-5Mo-5V-1Cr-1Fe titanium alloy with basket-weave microstructure was studied by the thermal compression experiment conducted at temperatures ranging from 1073 K to 1193 K and strain rates from 0.001 s⁻¹ to 1 s⁻¹. The results indicate that the stable flow state of the stress–strain curve of Ti-5Al-5Mo-5V-1Cr-1Fe alloy is rapidly reached within a small strain range (< 0.1). The majority of flow curves exhibit horizontal plateaus, which is attributed to the rapid equilibrium between dislocation accumulation and annihilation. Within the experimental parameters, the constitutive equation at ε = 0.3, thermal activation energy of 346.017 KJ mol⁻¹ and the strain rate sensitivity exponents between 0.25 and 0.4 for basket-weave microstructureTi-5Al-5Mo-5V-1Cr-1Fe titanium alloy with basket-weave microstructure were calculated. During hot deformation, there are phase transformations and several softening mechanisms, including lamellar spheroidization, dynamic recrystallization, dynamic recovery and their interactions. The β transition structures are cut by a large number of interleaved α lamellar structures, and the α lamellar structures are participated in coordinated deformation, which promotes the enhancement of strength and plasticity of Ti-5Al-5Mo-5V-1Cr-1Fe alloy. The model and microstructure analysis in this research can provide data reference for material selection and processing optimization of aircraft structural parts with high impact toughness and strength.