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镁合金由于密度小、比强度高、良好的导电和导热性而成为工业结构工程和运输工具中非常有应用前景的工程材料。但由于镁合金的耐磨性差,成为阻碍镁合金应用与汽车工业或其他工程部件中作为转动部件的一大障碍。为提高镁合金的表面耐磨性,各种表面处理技术应运而生。其中激光表面改性处理技术比较引人瞩目。为提高镁合金的表面耐磨性,采用激光熔覆纳米Al2O3颗粒的办法对ZM5镁合金进行了表面改性处理。激光改性是采用500 W脉冲Nd∶YAG熔化预置在ZM5表面的纳米三氧化二铝进行处理的。激光熔覆后,对改性层的显微结构进行了分析。同时对显微硬度与激光加工参数之间的关系以及耐磨性均进行了测试。改性层的显微硬度可以高达350 HV,而基材的显微硬度只有100 HV。激光改性处理层的耐磨性与基材相比也得到了显著的提高。
Due to its low density, high strength, good electrical conductivity and thermal conductivity, magnesium alloy has become a very promising engineering material in industrial structural engineering and transportation. However, due to the poor wear resistance of magnesium alloys, a barrier to the use of magnesium alloys and the automotive industry or other engineering components as a major obstacle to rotating parts. In order to improve the surface wear resistance of magnesium alloys, a variety of surface treatment techniques came into being. Among them laser surface modification technology is more attractive. In order to improve the surface wear resistance of magnesium alloy, laser cladding of nano-Al2O3 particles was used to modify the surface of ZM5 magnesium alloy. The laser modification is performed by using 500 W pulsed Nd: YAG melt pre-arranged on the surface of ZM5 nano-alumina. After laser cladding, the microstructure of modified layer was analyzed. At the same time, the relationship between microhardness and laser processing parameters and wear resistance were tested. The micro-hardness of the modified layer can be as high as 350 HV, while the micro-hardness of the substrate is only 100 HV. The wear resistance of the laser-modified layer has also been significantly improved over the substrate.