Hydrophobicity and Wear Resistance of Textured Carbon Fiber/Polytetrafluoroethylene Composite Coatings

In the process of unconventional oil and gas resources exploitation, bit balling and life of polycrystalline diamond compact (PDC) bit. PDC bits are common problems to be solved. Polytetrafluoroethylene (PTFE) coating is suitable for PDC bit steel, but we need to use surface technology to further improve the hydrophobic and tribological properties of PTFE coating. In this study, carbon fiber (CF)-modified PTEF composite coating was prepared on 35CrMo steel substrate by one-step spraying method and was then laser textured. The effects of CF with different mass fractions (10, 20, 30%) of 200 μm texture diameter and 100 μm spacing on the contact angle, friction coefficient and wear rate of the composite coating were studied. When the mass fraction of CF is 30%, the hydrophobic property of the coating is the strongest. When the mass fraction of CF is 20%, the coating has good tribological properties under certain hydrophobicity. The research content of this paper has certain guiding significance for solving the problem of PDC bit balling and the service durability of composite modification layer.