Structural evolution and mechanical properties of Ti-41Zr-7.3Al alloy during continuous cooling process

Abstract

The structural evolution and mechanical properties of Ti-41Zr-7.3Al alloy during continuous cooling process are investigated. X-ray diffraction (XRD) and transmission electron microscopy (TEM) are used to analyze the phase transformation and microstructure evolution, meanwhile, mechanical properties are obtained by tensile test. According to the results, the kinetics parameters of β→α phase transformation can play a decisive role for the microstructure and mechanical properties of titanium (Ti) alloys, and the quantitative relationship between the kinetics parameters and the strength of Ti-41Zr-7.3Al alloy has been established. Based on diffusion controlled growth mechanism of lamellar α phase and Hall–Petch relationship, the strength of Ti-41Zr-7.3Al alloy relies on the onset transition temperature during cooling T0, and cooling rate v has been deduced as σ=1102+1024[(T0−767)/ν]−1/4.