Process and Performance of β-SiCp/Al Prepared by Bottom-Vacuum Pressureless Infiltration

摘要:

采用底部真空无压浸渗新工艺制备了β-SiCp/Al 复合材料。SiC预制体在1373 K高温氧化及被熔融铝浸渗时加入Si、Mg合金元素。通过金相显微镜及SEM表征了复合材料的表面和断口形貌。结果表明，SiC颗粒在基体铝中分布均匀，SiC预制体浸渗完全。XRD分析表明，复合材料中的主晶相为SiC和Al，存在Mg2Si，MgAl2O4 界面产物，没有出现Al4C3脆性相。复合材料的力学性能研究表明，复合材料的磨损机制为磨粒磨损和黏着磨损；随着SiC体积分数的增加，复合材料的磨损率下降，硬度上升

Abstract:

A composite material β-SiCp/Al was fabricated by a novel manufacturing process of bottom-vacuum pressureless infiltration. The β-SiC perform was oxidized at 1373 K and the infiltration in molten Al with the addition of Si and Mg. To evaluate the microstructure and the fractograph of the prepared composites, metallographic and scanning electron microscopes (SEM) were applied. The results reveal that SiC particles can be distributed in the aluminum matrix uniformly, the SiC preform can be completely infiltrated by the molten aluminum. X-ray diffraction (XRD) shows that the main crystalline phases in the composites are β-SiC and Al. There exist Mg2Si, MgAl2O4 interface products, brittle phases such as Al4C3 are not formed within the interface zone. Mechanical properties of the β-SiCp/Al composites were investigated by the wear and friction, Brinell hardness tests. The results prove that the wear mechanisms of the composites are abrasive and adhesive wear. With the increased of SiC volume fraction the wear rate of the composite decreases while the hardness increases