Cu-Ni-Ti合金高温热变形行为及热加工图

High temperature deformation behavior and hot processing map of Cu-Ni-Ti alloy

采用MMS-100热力模拟机对Cu-Ni-Ti合金进行了温度为700~850℃、变形速率为0.01~10 s-1的等温压缩试验。研究表明,流变应力随应变程度增加快速上升至极限值后逐渐转变为平缓曲线,随温度增加而降低,随应变速率增加而上升。基于应力与变形速率和应变温度之间的关系,构建了Cu-Ni-Ti合金的本构方程和热加工图。得到了Cu-Ni-Ti合金较优热加工工艺:温度为840~850℃,应变速率为0.1~1 s^(-1)。较优工艺条件下,组织为动态回复、再结晶的晶粒,失稳区组织多为细长的纤维组织。

The Cu-Ni-Ti alloy was subjected to isothermal compression tests at temperatures ranging from 700 to 850℃with deformation rates ranging from 0.01 to 10 s-1 using MMS-100 thermal simulator.The results showed that with the increase of strain,the flow stress rapidly rose to the limit value and then gradually turned into an easy curve.The flow stress decreased with the increase of temperature and increased with the increase of strain rate.Based on the relationship between stress,deformation rate and strain temperature,the constitutive equation and hot processing map of Cu-Ni-Ti alloy were constructed.The optimal processing conditions of Cu-Ni-Ti alloys were in the range of temperature 840~850℃and strain rate 0.1~1 s^(-1).Under the optimal process conditions,the microstructure was an equiaxed crystal with dynamic recovery and recrystallization grain,and slender fibrous structure could be mostly found in the instability zone.