Study on wear resistance of HVOF metal ceramic composite coating

Abstract:

In order to improve wear resistance of the key wearable parts of deep drilling tools, high velocity oxygen fuel spray (HVOF) technology was used to prepare WC-10Co4Cr coating on 35CrMo steel substrate. The scanning electron microscope (SEM), X-ray energy dispersive spectrometer (EDS), X-ray diffractometer (XRD), micro-hardness tester, Vickers hardness tester and friction and wear tester were used to analyze the microstructure, mechanical properties and friction and wear behavior of the coating. The results showed that the WC-10Co4Cr coating prepared by HVOF technology had a dense microstructure and excellent mechanical properties. The porosity of the coating was 1.3±0.1%, with the microhardness of 1392 ± 45 HV0.3, and the fracture toughness of 7.11 ± 0.10 MPa·m1/2. Compared with 35CrMo steel substrate, the coating has more excellent wear resistance, and with the increase of sliding speed, the friction coefficient of WC-10Co4Cr coating decreases and the wear rate increases; The wear failure mechanism of coating mainly includes abrasive wear, adhesive wear and fatigue wear.

Key words:deep drilling; high velocity oxygen fuel (HVOF); WC-10Co4Cr coating; tribological property; wear mechanism