某新型粉末高温合金热压缩变形特性的研究

Study on the Hot Compressive Deformation of a New P/M Superalloy

采用Gleeble-1500热模拟机研究了某新型粉末合金在变形温度为1070～1170℃、应变速率为5×10-4s-1～2×10-1s-1的热压缩塑性变形行为,分析了合金流变应力、应变速率、变形温度之间的关系。结果表明,该合金的真应力-应变曲线在高应变速率下(ε≥2×10-2s-1),呈现出典型的动态再结晶特征,低应变速率下(ε≤2×10-3s-1),呈现动态回复特征;热塑性变形流变行为可用包含Arrhenius项的Z参数描述;随着变形温度的提高,该合金的应变速率敏感指数值变化很小。

The flow stress features of a new type P/M superalloy during platic deformation at elevated temperature were studied by the isothermal compression test using gleeble-1500 hot simulator.The compression test was performed in the temperature range from 1070℃ to 1170℃ and in the strain rate range 5×10^(-4) s^(-1) to 2×10^(-1) s^(-1).The experiments result show that curves of true stress(σ)-true strain (ε) at the higer strain rate (≥2×10^(-2) s^(-1)) are the type of the dynamic recrystallization and are the type of the dynamic recovery at the lower stain rate (≥2×10^(-3)s^(-1)).The flow behavior can be well described by zener-hollomon parameter including the arrhenius term.The strain rate sensitivity exponent increases little with increasing deformation temperature.