用挤压铸造法制备了SiC/Al双连续相复合材料，研究了工艺参数和SiC泡沫增强体对基体凝固组织的影响，以及复合材料的凝固机制。结果表明，工艺参数对复合参数材料凝固组织有重要的影响。正压加压制备的复合材料组织比反压加压均匀，提高复合压力可以细化基体的组织，但效果不明显。随着SiC泡沫增强体预热温度的降低，基体中α－Al柱状枝晶晶粒逐渐减小。SiC泡沫增强体对基体的晶粒尺寸没有明显的影响，但是改变了晶粒的形态。泡沫孔内的α-Al初晶表现为粗大的柱状晶，其方向垂直于泡沫增强体的筋。泡沫孔的尺寸越小，越容易形成枝晶组织，枝晶的方向性越强。SiC/Al双连续相复合材料基体凝固时，α－Al首先在泡沫筋的附近形核，然后逐渐向泡沫孔的中心长大。α－Al枝晶形成轮廓以后，中心富硅区发生共晶反应，形成筋表面的共晶硅。
SiC/Al co-continuous composites were fabricated by squeeze casting method, and the effect of SiC foam and process parameters on their solidification, the mechanism of solidification were investigated. The results show the process parameters play important roles in the solidification of composites. The microstructure of composites fabricated by positive squeeze is more uniform than that of composites made by inverse squeeze. The grain of composites is becoming smaller with the increase of squeeze casting pressure, but the change is not obvious. And the grains of composites is also bigger with the enhance of preheat temperature of SiC foam reinforcement. The size of grain is not obviously change, but the morphology of grain is different when the reinforcement is joined into the matrix alloy. The column dendrite that is perpendicular to the strut of SiC foam is easily got when the aperture of reinforcement is smaller. When SiC／Al composites start to solidify, the primary column dendrite α－Al is gotten near the strut of SiC foam, firstly. Then column dendrite α－Al is present after α－Al is growing into the central of aperture. At last, the eutectic silicon appears at the central of aperture where different column dendrite α－Al gathers before the eutectic reaction occurs at the surface of strut.
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