在Gleeble-1500D热模拟试验机上,采用高温等温压缩试验,对Cu-2.0Ni-0.5Si-0.15Ag合金在应变速率为0.01~5s^-1变形温度为600~800℃、最大变形程度为60%条件下的流变应力行为进行了研究。分析了实验合金在高温变形时的流变应力和应变速率及变形温度之间的关系。并研究了在热压缩过程中组织的变化。结果表明:热模拟实验中,应变速率和变形温度的变化强烈地影响合金流变应力的大小,流变应力随变形温度升高而降低,随应变速率提高而增大。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。
The flow stress behavior of Cu-2.0Ni-0.5Si-0.15Ag alloy during hot compression deformation was studied by isothermal compression test at a Gleeble-1500D thermal-mechanical simulator at the temperature from 600℃ to 800℃ and at the strain rate from 0.01s^-1 to 5s^-1 under maxium strain of 60%. The relationship among the flow stress, strain rates and deformation temperatures was studied. The microstructure of the experimental alloy was studied in the process of hot-compression. The results show that the flow stress is controlled by both strain rate and deforming temperature, the flow stress decreases with the increase of deforming temperature, while increases with the increase of strain rate. Stress index n, stress scale parameter α, structural factor A, hot deformation activation energy Q, and constitutive equation were derived from the correlativity of flow stress, strain rate and temperature. Microstructure of the alloy strongly depends on deformation temperature.