激光熔覆钴基合金涂层组织与性能

o61.2B26.2Si7.8Ta4.8 alloy coatings were prepared by laser cladding on the 45# medium steel. The microstructure and properties of the coatings obtained at different laser power were investigated by means of X-ray diffraction, scanning electron microscopy, electron probe micro-analyzer, Vickers hardness tester, frication wear testing machine. The results showed that the microstructure of the clad layer is featured with Co2B equiaxed dendrite distributing on the amorphous matrix. Because of changes of liquid composition and solidification parameters, crystallization phenomenon occurs in the edge zone of the clad layer, where Co2B and Co3B phases are formed. With increasing depth of the clad layer, Morphology of the Co2B changes from dendrite and columnar crystal. While the interface bonding zone consists of α'-(CoFe) phase dispersing on the α-(CoFe) matrix. With increasing laser power, average hardness value of the coating decreases due to increasing of amorphous phase content，as well as decreasing in content of Co2B intergranular precipitation at the edge zone, while wear resistance and anti-attrition property increase gradually.