Microstructures of W-17Co coating produced by plasma melt sprayingⅡ

W-17Co metallic ceramic coating was produced by plasma melt spraying(PMS) on low carbon steel Q235.Metallurgical bonded coating had been obtained.Microstructures,phases and compositions of the coating were analyzed with optical microscope,scanning electron microscope,transmission electron microscope,and energy dispersive spectroscope.The results showed that microstructures of PMS coating were very complicated,and distributed in different regions in the coating.The surface layer consisted mainly of cross-shaped primary carbide Fe₃W₃C,herring bone structure(γ-Fe+Fe₃W₃C),black belt around the herring bone structure,and the matrix.The middle layer consisted mainly of coarsened primary carbide dendrite Fe₃W₃C and interdendrite eutectoid(γ-Fe+Fe₃W₃C or FeW₃C).And structures in the bottom layer were fine,and consisted mainly of WC,primary Fe₃W₃C carbide and eutectoid(γ-Fe+Fe₃W₃C or FeW₃C).