Friction Behavior of Molybdenum Disulfide/Polytetrafluoroethylene-Coated Cemented Carbide Fabricated with a Spray Technique in Dry Friction Conditions

Cemented carbide has a relatively high surface friction coefficient, which can result in increased wear and energy consumption during friction, ultimately impacting service life and efficiency. In order to improve the tribological properties of the traditionally cemented carbide, the MoS2 and PTFE (25 wt.%) mixed powders, which were blended with Polyamide-imide (PAI) as the adhesive, were sprayed on the carbide surface at 70 °C. Tests were used to measure the performance of MoS2/PTFE-coated carbide, such as surface micrographs and cross-section micrographs, surface roughness, adhesion strength between coatings and substrate, and surface microhardness. Sliding friction tests were performed to investigate the friction performance. The test results showed that the adhesion strength between the coatings and substrate was up to 36 N, the hardness was about 0.42 GPa, and the friction coefficient was reduced by about 70%. The lower shear strength of MoS2/PTFE coatings led to the reduction of friction and wear. The main wear mechanisms of MoS2/PTFE coatings were surface abrasion and coating flaking. The MoS2/PTFE coatings present a promising approach to enhance the friction performance of traditional cemented carbide.