Ti551钛合金热变形行为及热加工图研究OA

To investigate the hot deformation behavior of Ti551 titanium alloy,isothermal compression tests were conducted at temperatures ranging from 800℃to 950℃and strain rates between 0.01-1 s-1.Based on the true stress-true strain data,the hot deformation characteristics of Ti551 titanium al-loy were systematically analyzed.The results indicate that the flow stress of the Ti551 titanium alloy is highly sensitive to variations in temperature and strain rate.An Arrhenius-type constitutive model incor-porating strain compensation was established to describe the hot deformation behavior of the alloy,and the predictive capability of the model was evaluated.Furthermore,processing maps were constructed using the Prasad instability criterion,revealing the distribution characteristics of power dissipation effi-ciency and instability domains as functions of temperature and strain rate.The optimal hot processing window for the Ti551 titanium alloy was identified as the high-temperature and low-to-medium strain rate region,while potential flow instability regions were located in the low-temperature and high strain rate domain.In addition,the evolution of primary α-phase morphology and the variation in the α/β phase fraction under different deformation conditions were investigated.These results provide a theoret-ical basis for the design of hot working process parameters and the microstructure-property optimiza-tion of Ti551 titanium alloy.