2099合金热变形加工图研究

Processing Map of 2099 Alloy Deformed at High Temperature

采用Gleeble-1500热模拟试验机对2099合金进行等温热压缩试验，研究了基于动态材料模型的加工图，分析了该合金在变形温度为300～500℃，应变速率为O．001～10S。范围内安全区和失稳区的组织特征，并对其热加工工艺进行优化。结果表明，2099合金的加工失稳区主要位于300～420℃，0．001～0．02S-1和300～500℃，0．562～10S-1范围内。失稳区组织出现了局部流变、局部剪切、局部流变＋局部剪切等特征；安全区组织以动态回复、动态回复＋动态再结晶为主要特征。合金热加工工艺优化为：真应变〈1．1时，工艺参数为380～420℃，0．025～1S-1；真应变〉3．4时，工艺参数为420～500℃，0．001～0．562S-1。

A processing map based on dynamic material modeling of 2099 alloy was investigated by isothermal compression tests on a Gleeble-1500 machine. Microstructure characteristics of safety areas and instability areas in the temperature range of 300-500 ℃, strain rate of 0.001-10 s-1 of 2099 alloy were analyzed. And the optimized processing parameters were also proposed. Results show that the instability areas of 2099 mainly locate in the regions of300-420 ℃, 0.001-0.O2 s-1 and 300-500 ℃, 0.562-10 s-1. Microstructure in the instability areas displays local plastic deformation, local adiabatic shear and local plastic deformation ＋ local adiabatic shear. The main deformation mechanisms in safety areas are dynamic recovery and dynamic recovery ＋ dynamic recrystallization. The optimized processing parameters can be summarized as that when the true strain is less than 1.1, the processing parameters are 380～420 ℃ and 0.O25-1 s-1 when the true strain is over 3.4, the processing parameters are 420～500 ℃, 0.001-0.562 s-1.