30%SiCp/2024A1复合材料的热变形行为及加工图

Hot deformation behavior and processing map of 30%SiC_P/2024A1 composite

采用Gleeble-1500热模拟试验机，对30%SiCp/2024A1复合材料在温度为350～500℃、应变速率为0.01～10 s-1条件下进行热压缩试验，研究该合金的热变形行为与热加工特征，建立热变形本构方程和加工图。结果表明，30%SiCp/2024A1复合材料的流变应力随温度升高而降低，随应变速率增大而升高，说明该复合材料是1个正应变速率敏感的材料，其热压缩变形时的流变应力可采用Zener-Hollomon参数的双曲正弦形式来描述，在实验条件下平均热变形激活能Q为334.368 kJ/mol。热加工图表明30%SiCp/2024Al复合材料最适合加工的条件是变形温度为500℃，应变速率为0.01

In order to explore the compressive properties of aluminium-based composite reinforced with middle content SiC particles, the thermal compaction testing on 30%SiCp/2024A1 composite was carried out in the temperature range of 350～500 ℃ and the strain rate range of 0.01～10 s-1 on Gleeble-1500 hot-simulation machine; the hot deformation behavior and hot workability of the composite were studied, and the constitutive equation and processing map of the composite were also established. The results show that the flow stress decreases with increasing deformation temperature at a constant strain rate, and increases with increasing strain rate at constant temperature, indicating that the composite is a positive strain rate sensitive material. The flow stress behavior of 30%SiCp/2024A1composite during hot compression deformation can be represented by a Zener-Hollomon parameter in the hyperbolic sine form and the activation energy for hot deformation Q is 334.368 kJ/mol in the present experimental condition. The processing map established at the true strain of 0.5 shows that the deformation temperature of 500 ℃ and deformation rate of 0.01 s-1 are the best hot deformation condition.