YANG Xi ^{1, 2}, MA Wen ^{1, 2}, HAN Jipeng ³, HUANG Wei ^{1, 2}, LI Yingjie ^{1, 2}, YANG Ting ^{1, 2},
ZHANG Jingxin ^{1, 2}, LIU Ying ^{1, 2}

(1. Inner Mongolia University of Technology, Hohhot 010051, Inner Mongolia, China; 2. Inner Mongolia Key Laboratory of Thin Film and Coatings, Hohhot 010051, Inner Mongolia, China; 3. Inner Mongolia Boiler and Pressure Vessel Inspection and Research Institute, Hohhot 010020, Inner Mongolia, China)

Abstract: Amorphous alloys are solid materials far from equilibrium and disordered in structure. Their atoms do not have long-range order, and there are no defects such as grain boundaries and segregation of crystal materials. They exhibit homogeneity and uniform structure, so they have high hardness, excellent wear and corrosion resistance. An amorphous coating of elemental composition Fe_51.1Cr_18.1Mo_30.8 was prepared by high velocity oxygen fuel spraying (HVOF). X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), micro-hardness tester and abrasive wear tester were used to study the microstructure, structural characteristics, elemental composition, microhardness and wear resistance of the coating. The results show that the coating has a low porosity (about 1.2%), an amorphous phase content of 94.8%, and a hardness of 1159 HV_0.2, which is much higher than the 316L stainless steel substrate. The coating also has better wear resistance than 316L stainless steel substrate. Characteristic temperature characterization and thermal stability analysis were performed by differential scanning calorimeter (DSC). The results show that the coating has good thermal stability. The passivation behavior of amorphous coatings in different media was analyzed by electrochemical workstation and compared with stainless steel. The results show that compared with stainless steel, the amorphous coating has the characteristics of wide passivation interval and strong resistance to breakage of passivation film.

Key words: HVOF; amorphous coating; wear and corrosion resistance; passivation