Wear mechanism of a laser cladded Fe-based self-lubricating composite coating for protecting counter-abrasive parts

Abstract

Under specific requirements, wear must be limited to certain parts. In this study, self-lubricating coatings were prepared by laser cladding to improve the service life of wear parts (current material is Cu-based materials) in a tire mold. Five novel alloy powders (C1: FeCrNiMo, C2: FeCrNiMo+10 wt%Ni/MoS2, C3: FeCrNiMo+20 wt%Ni/MoS2, C4: FeCrNiMo+20 wt%Ni/MoS2 + 10 wt%nano-Cu, and C5: FeCrNiMo+20 wt%Ni/MoS2 + 10 wt% micro-Cu) were designed. Moreover, the hardness, phase composition, and microstructure of the coating were studied. A friction and wear study under simulated vulcanization conditions with the tire mold 40Cr nitrided layer (counter-abrasive parts) was carried out. Friction coefficients of the C1, C2, and C3 cladding layers were above 0.5, and caused the wear of the 40Cr nitrided layer. The C4 and C5 cladding layers did not cause wear of the 40Cr nitrided layer in the entire friction process, and the wear resistance of was higher than that of the Cu-based wear-resistant plate used in the original design. Soft metal Cu in the coatings could synergize with CrxSy to generate a complete lubricating film to protect the wear parts from wear. This study provides a laser cladding Fe-based self-lubricating composite coating that can effectively protect abrasive parts.