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将无压浸渗制备出的高体积分数SiCp/Al复合材料,通过高温反挤压方式成形杯形件.研究了在高温反挤压过程中复合材料的流变规律,利用扫描电镜(SEM)观察分析了高温反挤压参数对杯形件组织的影响.结果表明:在基体熔点以上,高体积分数SiCp/Al复合材料呈黏流体状态,颗粒与基体形成固-液混合体;高体积分数SiCp/Al复合材料高温反挤压变形后,基体仍保持连续,SiC颗粒在压力作用下发生转动、重排,部分颗粒破碎,颗粒分布均匀性较好;当变形温度较低、挤压速度较大时,颗粒易破碎,SiCp/Al复合材料杯形件内部颗粒尺寸不均匀,杯形件内角处颗粒尺寸较小;当变形温度较高、挤压速度较小时,杯形件内部颗粒尺寸均匀.
The high volume fraction SiCp / Al composites prepared by pressureless infiltration were molded into cup by high temperature reverse extrusion method.The rheological behavior of the composites during high temperature reverse extrusion process was studied by SEM, The effect of high-temperature anti-extrusion parameters on the cup structure was observed and analyzed.The results show that the SiCp / Al composites with high volume fraction are in a viscous fluid state above the melting point of the matrix and form a solid-liquid mixture with the matrix; the high volume fraction The SiCp / Al composites remain in continuous state after the high temperature reverse extrusion deformation. The SiC particles rotate and rearrange due to the pressure, and some of the particles are broken and the particle distribution is better. When the deformation temperature is lower and the extrusion speed is lower The particles are easily broken, the internal particle size of the SiCp / Al composite cup is not uniform, and the particle size at the inner corner of the cup is smaller; when the deformation temperature is higher and the extrusion speed is smaller, the internal particle size of the cup is even .