碳化硅颗粒增强铝基复合材料以其高比强度、高比模量、优良的导热性和摩擦磨损性能等特点，在航空航天、体育器材、汽车等领域具有广阔的应用前景。本文采用复合铸造法制备SiCp/6066Al复合材料，利用金相显微镜(OM)和扫描电镜（SEM）分析了SiC颗粒的表面形貌和复合材料的显微组织，利用X-射线衍射仪（XRD）分析了复合材料的相结构，利用布氏硬度计测试了复合材料的硬度，研究了SiC颗粒表面处理工艺和搅拌工艺参数对复合材料的显微组织和硬度的影响规律，并通过正交实验对搅拌工艺参数进行了优化。获得的主要结果如下： （1）经过酸洗+高温氧化处理的SiC颗粒表面附有非晶态的SiO2膜，其棱角明显钝化；经过碱洗+氟酸盐处理的SiC颗粒表面变得粗糙，并有少量K2ZrF6盐析出；经过碱洗+酸洗处理的SiC颗粒表面洁净，其棱角稍有钝化。 （2）SiC颗粒的表面处理方法对其在基体中的分散性和复合材料的硬度有较大影响。经碱洗+氟酸盐处理的SiC的分散性最好，复合材料的硬度最大；未经任何处理的原始态SiC的分散性最差，复合材料的硬度最小。 （3）在同等条件下，搅拌温度为620℃或搅拌速度为600r/min时，颗粒分布比较均匀，温度或速度过低，颗粒难以分散，团聚现象严重，过高则颗粒难以进入熔体或熔体吸气严重；本实验条件下，随着搅拌时间的延长，颗粒的分散性不断提高。搅拌温度、搅拌速度、搅拌时间对复合材料硬度的影响表现出与显微组织类似的规律。 （4）正交实验结果表明，在620℃、600r/min、45min条件下，复合材料的气孔率最低，约为3.9%。 （5）复合材料中SiC颗粒与基体的界面结合强度适中，拉伸断口中既有SiC颗粒的拔出，也有SiC颗粒的断裂，基体表现为韧性断裂。

SiC Particle reinforced aluminum matrix composites are widely used in aerospace, sports equipment, automotive and other industrial fields because of their high specific strength, specific modulus, good thermal conductivity and wear resistance. In this paper, the SiC/6066Al composites were prepared by composite casting. The surface morphology of SiC particles, microstructures and phase structure of the composites were analysed by OM, SEM, XRD. Using Brinell hardness tester measured the hardness of the composites, the effects of SiC particles surface treatment and stirring parameters on the microstructures and hardness of composites were studied, and the stirring parameters were optimized by orthogonal experiment. The main results obtained are as follows： (1) After pickling and high temperature oxidation treatment, the surface of SiC particles have amorphous SiO2 film, the edges and corners were passive; after treatment, the surface of SiC particles becomes rough, and some K2ZrF6 salt precipitation; after alkaline cleaning and pickling treatment, the surface of SiC particles becomes clean, the edges were passive a little. (2) The surface treatment of SiC particles have a greater impact on its distribution in the matrix and hardness of the composites. SiC treated by alkaline cleaning and fluoride salts have a best distribution, the hardness of composites reach maximum; the original state SiC without any treatment have a worst distribution, the hardness of composites reach minimum. (3) Under the same conditions, when stirring temperature is 620℃ or the stirring speed is 600r/min, particles distribute uniform, if temperature or speed is too low, particles are difficult to disperse, agglomeration serious, too high, particles are difficult to enter the melt or melt suck Gas serious; at the experimental conditions, with the stirring time grows, the dispersion of particles increasing. Stirring temperature, stirring speed and stirring time on the hardness of composites showed a similar pattern to microstructure. (4) Orthogonal experimental results show that : in 620℃, 600r/min, 45min conditions, composites get the lowest porosity which is about 3.9%. (5) The interfacial bond strength between SiC particles and the matrix is moderate, the main fracture mode of composites are the fracture of SiC particles, debonding of SiC/Al interfacial, matrix ductile fracture.