Ceramic Coating of WC-Co-NiCrAl/Laser-Remelting Microstructure and Corrosion Characteristics

Ceramic coating of WC/Co-NiCrAl(TC-1) coating was formed by plasma spraying technology on 1045 steel surface.Ceramic coating of WC-Co-NiCrAl/laser-remelting(TC-2) was formed by laser-remelting of the plasma spraying coating.Using nano-SiC powder material as the coating stuff,laser was also employed to remelt the plasma spraying coating,and the composite ceramic coating of WC/Co-NiCrAl/nano-SiC was formed(TC-3).The microstructures of three kind of composite ceramic coating were investigated using X-ray diffraction and scanning electron microscopy.Also,corrosion behavior of the coatings was studied.The results show that TC-1 ceramic coating consists of WC,W2C,W6C2.54,W,Co and CoO;TC-2 ceramic coatings are WC,W2C,CoC and W;TC-3 ceramic coatings are SiC,Si2W,WC,W and CoO.Lamella structure characteristic of plasma-sprayed coatings were eliminated after the laserremelting.TC-2 and TC-3 ceramic coatings have higher dense and better corrosion resistance than plasma sprayed TC-1 coating.