Study of Microstructure and Phase of Plasma Sprayed Cr3C2-NiCr Coating before and after the Sparking Plasma Sintering

Plasma sprayed chromium carbide coating has poor adhesion strength and wear-resistance, sparking plasma sintering(SPS) process can change the coating microstructure and improve its performance. The microstructure and phase of plasma sprayed Cr3C2-NiCr coating before and after the sparking plasma sintering were studied in this paper. The results show that the microstructure of plasma sprayed Cr3C2-NiCr coating after SPS become more compact and most of the pores and micro-cracks disappear. Some new oxides appear after SPS process. Hard Chromium carbides and oxides phase distribute in the NiCr-based solid solution to improve the wear resistance of the coating. Obvious crack at the interface has disappeared. The coating and the substrate form a good metallurgical bond.