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鉴于铝合金的广泛应用价值及其因质软而在应用方面受到的限制 ,应用激光材料表面复合化方法对铝合金材料表面进行强化处理 ,具体为利用Nd∶YAG脉冲激光采用纳米级和微米级SiC粉对铝合金表面进行复合化处理。通过对实验结果观察和分析表明 ,纳米级SiC粉形成激光铝合金表面复合化涂层比微米级SiC粉所形成复合化涂层组织均匀、致密、缺陷少、涂层与基材间结合状态好并显著提高了铝合金表面的显微硬度。分析原因在于微米级SiC粉在激光熔池内发生沉降 ,而纳米级SiC粉可在激光熔池内形成较均匀分布 ,这是重力作用受粉颗粒大小影响显著的结果。从而可以看出 ,SiC颗粒形状、大小及其在涂层中的分布状态直接影响涂层组织特征、涂层与基材间的结合状态 ;把形状规则、颗粒细小、在涂层中能够形成均匀分布的SiC粉作为涂层复合物有利于形成组织特征均匀、缺陷少、与基材结合状态好的复合涂层。
In view of the wide application value of aluminum alloy and its application in the soft due to its limitation, the surface of the aluminum alloy material is strengthened by the surface composite method of the laser material, in particular, the use of Nd: YAG pulsed laser with nano-and micro-scale SiC powder composite treatment of aluminum alloy surface. Through the observation and analysis of the experimental results, it is shown that the composite coating formed by nano-sized SiC powder on the surface of the laser aluminum alloy composite is more uniform and dense than the micron-sized SiC powder, the defects are few and the bonding state between the coating and the substrate is good And significantly increase the microhardness of the aluminum alloy surface. The reason for the analysis is that the micrometer-sized SiC powder settles in the laser pool while the nanometer SiC powder forms a more uniform distribution in the laser pool, which is a significant effect of gravitation on the particle size. It can be seen, SiC particle shape, size and distribution in the coating state directly affect the coating tissue characteristics, the coating and substrate bonding state; the shape of the rules, small particles in the coating to form a uniform The distribution of SiC powder as a coating composite is conducive to the formation of a composite structure with uniform microstructure, less defects and good bonding with the substrate.