AZ61 magnesium alloy metal matrix composites (MMCs) with different weight percentages (0, 1 and 2) of micro-silicon carbide particles (SiCp) were fabricated using stir casting method. Effects of SiCp on the microstructural distributions, mechanical and fatigue properties, and fracture surfaces have been investigated. The microstructural observations of as-cast MMCs unveil the existence of primary α-Mg phase and the presence of large amount of β-Mg₁₇Al₁₂ secondary phase at grain boundary. The specimens are subjected to homogenization heat treatment at 410 °C for 24 h; the β-Mg₁₇Al₁₂ phases are significantly dissolved in the matrix grain boundaries which enhance the ductility and decrease the hardness compared with the as-cast materials. The addition of SiCp reinforcement led to improved yield strength (YS) and ultimate tensile strength (UTS) of AZ61/SiCp composite compared to the unreinforced alloy. The maximum values of YS and UTS have been attained at AZ61/1wt%SiCp composites. The enhancement of YS and UTS was due to the presence of a uniformly distributed reinforced SiCp, which depends on grain refinement of the matrix and strong interfacial bonding between the matrix and reinforcement. In the case of fatigue test results, the addition of SiCp reduced the fatigue life and strength of AZ61 alloy composite. However, addition of 1wt%SiCp showed good mechanical and fatigue properties compared to pure AZ61 magnesium alloy and AZ61/2wt%SiCp composite. Furthermore, the effects of addition of SiCp on the mechanical and fatigue properties of the composite were confirmed by using the scanning electron microscope observation of fracture surfaces.

采用搅拌铸造法制备了具有不同重量百分比（0、1、2）的微碳化硅颗粒（SiCp）的AZ61镁合金金属基复合材料（MMCs）。已经研究了SiCp对显微组织分布，机械和疲劳性能以及断裂表面的影响。铸态金属基复合材料的微观结构观测揭示初生α-Mg相的存在和大量β-Mg系的存在₁₇的Al ₁₂二次相在晶界。将样品在410°C下进行均质化热处理24 h；的β-Mg系₁₇的Al ₁₂与铸态材料相比，相明显溶解在基体晶界中，从而提高了延展性并降低了硬度。与未增强的合金相比，添加SiCp增强材料可改善AZ61 / SiCp复合材料的屈服强度（YS）和极限拉伸强度（UTS）。在AZ61 / 1wt％SiCp复合材料上，YS和UTS达到最大值。YS和UTS的提高归因于存在均匀分布的增强SiCp，这取决于基体的晶粒细化以及基体与增强体之间的牢固界面结合。就疲劳测试结果而言，添加SiCp会降低AZ61合金复合材料的疲劳寿命和强度。然而，与纯AZ61镁合金和AZ61 / 2wt％SiCp复合材料相比，添加1wt％SiCp显示出良好的机械性能和疲劳性能。此外，通过使用扫描电子显微镜观察断裂表面，证实了SiCp的添加对复合材料的机械性能和疲劳性能的影响。