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为了研发高性能颗粒增强铝基复合材料,采用Gleeble-3800热模拟试验机,研究了粉末冶金15%SiC_p/2009A1复合材料在变形温度为370~520℃、应变速率为0.01~10.00 s-1条件下的高温变形特性。结果表明,当变形速率一定时,该复合材料的流变应力随变形温度升高而降低;当变形温度一定时,复合材料的流变应力随应变速率增大而提高。采用动态材料模型建立了15%SiC_p/2009A1复合材料的热加工图。热加工图表明,在较高应变速率区域(2.00~10.00 s~(-1)),出现流变失稳,有少量颗粒—基体界面开裂和SiC颗粒本身破碎。该复合材料的动态再结晶区域位于加工图的较低应变速率区域(<1.00 s~(-1)),功率耗散率值较为适中,为0.24~0.35,此时材料具有良好的塑性,适合进行热加工变形。综合加工图以及微观组织观察结果,获得了复合材料热变形的最佳工艺参数:变形温度为450~490℃、应变速率为0.01~0.10 s~(-1)。
In order to develop high-performance particle reinforced aluminum matrix composites, using the Gleeble-3800 thermal simulator, the effects of the deformation temperature of 370 ~ 520 ℃ and the strain rate of 0.01 ~ 10.00 s-1 on the 15% SiCp / Under the high temperature deformation characteristics. The results show that when the deformation rate is constant, the flow stress of the composites decreases with the increase of the deformation temperature. When the deformation temperature is constant, the flow stress of the composites increases with the strain rate increasing. A hot working diagram of 15% SiC_p / 2009A1 composites was established by using dynamic material model. Hot working maps show that at higher strain rates (2.00-10.00 s -1), flow instability occurs, with a small amount of particle-matrix interface cracking and breaking of SiC particles themselves. The dynamic recrystallization region of the composite is located in the lower strain rate region (<1.00 s -1) of the working map, and the power dissipation rate is moderate, ranging from 0.24 to 0.35. In this case, the material has good ductility and is suitable for Thermal deformation. The results show that the optimum technological parameters of the thermal deformation of the composite material are as follows: the deformation temperature is 450 ~ 490 ℃ and the strain rate is 0.01 ~ 0.10 s ~ (-1).