Wear Mechanism of Iron-based Alloy Coating by Arc Spraying

The arc spraying technique was adopted to prepare three types of iron-based coatings including 08Mn2Si, 4Cr13, and 65Mn. Meanwhile, the metallurgical microscope and scanning electron microscope (SEM) were used to analyze the microstructure of these coatings. Besides, a DPT-5 dye penetrant was painted on the surface of the coatings to simulate the oil fluid, so as to observe its penetration in the pore structures. The MMU-5G end-face high-temperature wear tester was used to carry out wear-resistance tests on these coatings and give comparison with grey cast irons. The experimental results showed that the 4Cr13 coating exhibited the best wear resistance under oil batch lubrication condition. According to the study of these coating structures, it was discovered that three coatings presented topology-like structures due to the accumulation of flat particles on the matrices. Meanwhile, it was found that zonal oxides were mixed in particles with some unmolten particles, pores, and cracks. Besides, the larger pores were mutually connected by gap-like pores. The existence of FeO in the coating and the pore structures keep oil in acted antifriction effects.