在Gleeble-1500D热模拟试验机上,对Cu-2.0Ni-0.5Si-0.03P合金进行高温压缩实验,应变速率为0.01~5s^-1、变形温度为600~800℃,对其高温等温压缩流变应力行为进行了研究。研究结果表明:随变形温度升高,合金的流变应力下降,随应变速率提高,流变应力增大。在应变温度为750、800℃时,合金热压缩变形流变应力出现了明显的峰值应力,表现为连续动态再结晶特征。可采用Zener—Hollomon参数的双曲正弦函数来描述Cu-2.0Ni-0.5Si-0.03P合金高温变形时的流变应力行为。从流变应力、应变速率和温度的相关性,得出了该合金高温热压缩变形时的应力指数n,应力参数α,结构因子A,热变形激活能Q和流变应力方程。合金动态再结晶的显微组织强烈受到变形温度的影响。
High temperature compressive experiments of Cu-2.0Ni-0.5Si-0.03P alloy at 0.01-5s^-1 and 600-800℃ were performed on Gleeble-1500D thermal-mechanical simulator. The flow stress behavior of the alloy was studied. The results show that the flow stress decreases with the increase of deforming temperature, while increases with the increase of strain rate. When the deformation temperature is 750℃ and 800℃, the flow stress decreases after a peak value, showing continuous dynamic recrystallization. The flow stress of Cu-2.0Ni-0.5Si-0.03P alloy during high temperature deformation can be represented by a Zener-Hollomon parameter in exponential form. Stress index n,stress scale parameter a,structural factor A,hot deformation activation energy Q,and constitutive equation were derived from the correlativity of flow stress,strain rate and temperature. The microstructures was strongly depended on the deformation temperature.