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研究了两种不同初始组织(魏氏组织、马氏体组织)Ti-6Al-4V合金在温度区间为700~750℃,应变速率为10~(-3)~1s~(-1)之间的高温变形行为。结果表明:初始组织对Ti-6Al-4V合金高温变形行为有着重要影响,初始魏氏组织Ti-6Al-4V合金主要发生了绝热剪切变形,在试样内部形成了绝热剪切带,绝热剪切带的密度随着温度上升和应变速率下降而减小;α′马氏体组织Ti-6Al-4V合金主要发生了稳态变形,在试样内形成了晶粒尺寸在亚微米级甚至纳米级的超细晶组织,晶粒尺寸和组织均匀性随着温度升高和应变速率减小而增大。α′马氏体组织的晶粒细化机制主要是连续动态再结晶,α′/α+β相变过程为再结晶的发生提供了重要的驱动力。
Ti-6Al-4V alloy with two different initial microstructures (Westend tissue and martensite) was studied at a temperature range of 700-750 ℃ and a strain rate of 10 -3 to 1 s -1 The high temperature deformation behavior. The results show that the initial microstructure has an important influence on the high-temperature deformation behavior of Ti-6Al-4V alloy. The initial W-shaped Ti-6Al-4V alloy mainly undergoes adiabatic shear deformation and adiabatic shear band, adiabatic shear band The density of the cutting zone decreases with the increase of temperature and the decrease of the strain rate. Steady deformation occurs mainly in the α ’martensite Ti-6Al-4V alloy, and the grain size in the sample is submicron or even nanometer Grade ultra-fine grain structure, the grain size and the uniformity of the structure increase with increasing temperature and decreasing strain rate. The grain refinement mechanism of α ’martensite is mainly continuous dynamic recrystallization. The α’ / α + β phase transformation provides an important driving force for the recrystallization.