等离子束表面冶金铜铝金属间化合物涂层的研究

利用铜铝有一定互溶性并可生成金属间化合物的特点，采用等离子束表面冶金技术，以纯铝为基材，纯铜粉末为冶金原料，在铝表面制得了冶金结合良好的复合金属间化合物冶金层。借助OM、SEM、EDAX及XRD对试样显微组织进行分析，并测试了其显微硬度。结果表明：等离子束表面冶金快速凝固过程中，形成了Al2Cu金属间化合物及α（Al）固溶体。铜铝金属间化合物冶金层的组织具有快速凝固组织特征，冶金层底部为逆热流方向长大的粗大枝晶，上部为细小枝晶和大胞晶均匀分布。冶金层与基体间具有良好的冶金结合。冶金层的最高硬度为260HV，较铝基材的硬度（74．5HV）有显著提高。

Study on Cu-Al Inter-metallic Compound Coating by Plasma Beam Surface Metallurgy

In the paper,an inter-metallic compound coating bonded well is successfully deposited on the sur- face of Al by plasma beam surface metallurgy on the basis of good mutual solubility of Cu and Al.The com- mercially pure Al is used as a substrate and the pure Cu powders are metallurgical material for the plasma beam surface metallurgical process.Microstructure and micro-hardness properties of the metallurgical coat- ing are studied with the help of OM,SEM,EDAX and XRD.The results show that during rapid freezing of the plasma beam surface metallurgical process,inter-metallic compound of Al_2Cu and Al solid solution are separated out from the liquid.Optical microscope observation demonstrated that the microstructures of the inter-metallic compound coating are rapid,non-equilibrium freezing structures:the bottom of the metallur- gical coating is coarse dendrite microstructure against the heat and in the upper area is nearly uniform fine dendrite and cellular.The coating has high micro-hardness of 260HV,which greatly improved the surface hardness of the Al(74.5HV).