Microstructure and performance of the SiC/Stainless steel composite coating produced by Nd:YAG laser cladding

SiC reinforced iron matrix composite coatings have been successfully produced by using a 2 kW Nd: YAG laser on a 40Cr steel substrate and microstructure analysis and performance testing of the coatings are carried out. There are two forms of SiC used in the experiment: particle and fiber. By adjusting the adding content of SiCp and SiCf, the evolution of SiC of different forms during laser cladding, the existing forms of SiC in cladding layers and its affection on hardness of cladding layers are studied. The results show that during laser cladding, different forms of SiC are decompounded partially. With the increasing of the SiC adding content, the quantity of un-melt SiC is increased and the hardness of cladding layers is improved. Comparing the hardnesses of SiC particle reinforced coating and the SiC fiber reinforced coating, the reinforcing effecting of SiC fiber is higher. The main reasons of hardness remarkable improvement are disperse reinforcement of un-melt SiC and propitiation FeSiC, and solution reinforcement of decompounded Si, C.