SiC颗粒增强镁基复合材料的制备与组织性能研究

目的 研究SiC体积分数对复合材料显微形貌、物相组成、拉伸性能、磨损性能和腐蚀性能的影响。方法 采用粉末冶金法制备SiC_p/AS81复合材料，采用相关仪器设备对不同SiC体积分数的SiC_p/AS81复合材料的显微形貌进行观察，对物相组成和组织性能进行分析。结果 随着SiC体积分数的增加，SiC增强镁基复合材料的平均晶粒尺寸逐渐减小。0.25%(体积分数，下同)–SiC_p/AS81和0.50%–SiC_p/AS81复合材料中的Si元素分布较为均匀，而在1.0%–SiC_p/AS81复合材料中可见较多的Si元素团聚。随着SiC体积分数的增加，复合材料的抗拉强度、屈服强度和断后伸长率先增大后减小，均在SiC体积分数为0.50%时取得最大值。在5～30 N载荷下，0.50%–SiC_p/AS81复合材料的耐磨性能要优于AS81复合材料的耐磨性能。复合材料按耐腐蚀性能从高至低顺序排列如下：0.50%–SiC_p/AS81>0.25%–SiC

Preparation and Microstructure & Properties of SiC Reinforced Magnesium Matrix Composites

The work aims to investigate the effect of SiC volume fraction on microstructure, phase composition, tensile properties, wear resistance, and corrosion resistance of composites. Powder metallurgy was used to prepare SiCp/AS81 composites. Relevant instruments and equipment were used to observe the microstructure of SiCp/AS81 composites with different SiC volume fractions, and the phase composition and microstructure properties were analyzed. The results showed that the average grain size of SiC reinforced magnesium matrix composites decreased with the increase of SiC volume fraction. The distribution of Si elements in 0.25% (volume fraction, the same below)-SiCp/AS81 and 0.50%-SiCp/AS81 composites was relatively uniform, and many Si element agglomeration could be seen in 1.0%-SiCp/AS81 composites. With the increase of SiC volume fraction, the tensile strength, yield strength and elongation after fracture of the composites first increased and then decreased, and the maximum value was obtained when the SiC volume fraction was 0.50%. Under 5-30 N load, the wear resistance of 0.50%-SiCp/AS81 composites was better than that of AS81 composites. The order of corrosion resistance of composites from high to low was:0.50%-SiCp/AS81>0.25%-SiCp/AS81>AS81>1.0%-SiCp/AS81. 0.50%-SiCp/AS81 composites have the best comprehensive properties, which is mainly related to the fine and uniform grains, less material defects and high compactness of the composites.