高能超声场下熔体原位反应制备TiB2/Al-30Si复合材料及其耐磨性能

摘要

在高能超声场下利用熔体原位反应制备TiB2/Al−30Si复合材料；利用XRD、SEM及干磨损试验研究此复合材料的显微组织和磨损性能。结果表明：在高能超声场作用下，原位TiB2颗粒在铝基体中分布均匀，形貌为圆形或四边形，尺寸在0.1~1.5μm之间。初生硅的形貌为四边形，平均尺寸为10μm。随着高能超声功率的增加， Al−30Si基体合金及TiB2/Al−30Si复合材料的硬度明显提高；特别是当超声功率为1.2 kW时，复合材料的硬度达到412 MPa，是基体合金的1.3倍。复合材料的磨损性能得到明显提高，载荷的变化对复合材料的磨损量影响不大。%TiB2/Al−30Si composites were fabricated via in-situ melt reaction under high-energy ultrasonic field. The microstructure and wear properties of the composite were investigated by XRD, SEM and dry sliding testing. The results indicate that TiB2 reinforcement particles are uniformly distributed in the aluminum matrix under high-energy ultrasonic field. The morphology of the TiB2 particles is in circle-shape or quadrangle-shape, and the size of the particles is 0.1−1.5μm. The primary silicon particles are in quadrangle-shape and the average size of them is about 10μm. Hardness values of the Al−30Si matrix alloy and the TiB2/Al−30Si composites considerably increase as the high energy ultrasonic power increases. In particular, the maximum hardness value of the in-situ composites is about 1.3 times as high as that of the matrix alloy when the ultrasonic power is 1.2 kW, reaching 412 MPa. Meanwhile, the wear resistance of the in-situ TiB2/Al−30Si composites prepared under high-energy ultrasonic field is obviously improved and is insensitive to the applied loads of the dry sliding testing.