An experimental study on synthesizing submicron MoSi2-based coatings using electrothermal explosion ultra-high speed spraying method

The MoSi2-based coatings were synthesized on the surface of the low carbon steel substrate using electrothermal explosion ultra-high speed spraying method. Microstructure, phase structure, elements distribution and microhardness of the coatings were characterized by SEM, XRD, EDS and Vickers hardness tester, respectively. It is found that MoSi2 coating and MoSi2 + MoB2 multiphase coating were in-situ formed. The coatings have compact microstructure, submicron-grain and high hardness. The bonding of coating-substrate is metallurgical one. The hardness and microstructure of the MoSi2 coating were improved by boron alloying. The average and highest hardness of the MoSi2 coating are 1340 HV0.2 and 1390 HV0.2, respectively, and that of MoSi2 + MoB2 multiphase coating are 1650 HV0.2 and 1785 HV0.2, respectively.