Zr-1.0Ti-0.35Nb 合金热变形行为研究

The harsh environment with strong acid, high oxidability and irradiation raises urgent demand for advanced structural materials used for reprocessing dissolver of spent nuclear fuels. In this paper, hot compression behavior of a Zr-1.0Ti-0.35Nb alloy was investigated at the strain rate of 0.01, 0.1, 1 s^-1 and in the temperature range of 670-750 °C. Microstructural evolution during the hot compression was analyzed. The results reveal that the strain rate and deformation temperature both significantly affect the hot deformation behavior of Zr-1.0Ti-0.35Nb alloy. Flow stress increases with the accelerated strain rate and decreases with the elevated temperature. Beyond peak stress, the flow curve exhibits apparent dynamic recrystallization characteristics. Elevated deformation temperature favors dynamic recrystallization and grain growth. An Arrhenius-type constitutive model was established based on the obtained peak stress values, in which the activation energy is calculated as 225.8 kJ/mol, suggesting a Ti-induced elevation of activation energy and the hardening index is 5.62. A correlation coefficient of 0.97427 and average relative error of 6.15% are obtained between the experimental and predicted values, demonstrating sound applicability of the constitutive model that is expected to guide processing optimization for the new Zr-1.0Ti-0.35Nb alloy.