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研究了挤压前后SiC颗粒增强Mg-3.6Zn-0.6Y-0.2Ca基复合材料组织和力学性能.结果 表明:随挤压速率或挤压温度的增加,再结晶晶粒的尺寸增加,体积分数则略有增加.随挤压速率的增加,动态析出相的尺寸增加,体积分数减小.当挤压温度设定为230℃时随挤压速率由0.01 mm/s增加到0.1 mm/s,或当挤压速率设定为0.1 mm/s时挤压温度由190℃增加到230℃,复合材料的屈服强度和抗拉强度降低,而伸长率则逐渐增加.在优化的挤压参数(190℃,0.1 mm/s)下,挤压态复合材料的屈服强度、抗拉强度和伸长率分别为312.0 MPa,347.3 MPa和6.6％;其中晶粒细化对强度提升的贡献高于热错配强化与析出强化.“,”The microstructures and mechanical properties of a newly developed Mg-3.6Zn-0.6Y-0.2Ca matrix composite containing SiC particle before and after extrusion were investigated.Results show that the grain sizes of the as-extruded composites decrease as compared to the as-homogenized composite before extrusion.With increasing the extrusion speed or extrusion temperature,the size of recrystallized grains increases while the volume fraction slightly increases.The size of dynamic precipitated phases increases and the volume fraction decreases with increasing the extrusion speed.With an increase in extrusion speed from 0.01 mm/s to 0.1 mm/s at 230 ℃ or extrusion temperature from 190 ℃ to 230 ℃ at 0.1 mm/s,the yield strength and ultimate tensile strength decrease while the elongation increases.The yield strength,ultimate tensile strength and elongation of composites extruded under optimized extrusion parameters (190 ℃,0.1 mm/s) are 312.0 MPa,347.3 MPa and 6.6％,respectively.The contribution of grain refinement strengthening to the strength increment is higher relative to the thermal expansion effect and precipitate strengthening.