材料期刊网

The surface properties of ZM5 Mg-base alloy were modified by laser cladding with Al+Y powder. Laser cladding was carried out with a 5 kW continuous wave CO2 laser by melting the preplaced powder mixture of Al and Y. Following laser cladding, the cladding zone was characterized by a detailed microstructural observation and phase analysis. Moreover, the microhardness and element distribution were evaluated in detail. The surface modified layer consists of Mg-17 Al-12 and Al-4 MgY phases, while alpha-Mg and Mg-17 Al-12 in the substrate. The microhardness of the cladding zone was significantly enhanced as high as HV122 - 180 as compared to HV60 - 80 of the substrate region. The maximal hardness about HV224 is in the interface due to the formation of intermetallic Mg-17 Al-12 phase. The microstructure is refined and Mg diffuses into the cladding material which leads to the formation of Mg-17 Al-12.