Design and application of friction pair surface modification coating for remanufacturing

Friction, wear, and contact fatigue are the main causes of energy loss, material waste, and equipment failure. The aim of remanufacturing is to repair and modify the damaged equipment surface, and the surface coating is the major material that allows the remanufactured parts to be used in a new round of operation. Thus, the design and preparation of surface coatings are very important to repair, strengthen, or modify the friction pairs, in order to ensure long-term operation of the remanufactured parts. Recently, a lot of research on designing and preparing friction pair surface modification coatings has been conducted by the National Key Laboratory for Remanufacturing (NKLR). The research conducted achieved the following goals: the mechanism of micro/nano multilayer surface modification coatings with long-term efficacy life was revealed, and the corresponding design considerations and preparation methods of nanocrystalline micro tribological coatings were innovatively developed. A series of new “two-step” processes to prepare sulfide solid lubricating coatings were developed. The competitive failure mechanism of the surface coating in simultaneous wear and fatigue conditions was revealed, and some composite coatings with dual properties of wear resistance and fatigue resistance were prepared. Based on the stress distribution of friction surface contact areas and the piezoelectric effect, a failure warning intelligent coating is designed and developed. These coatings have been successfully applied to critical friction components, such as the spindle of large centrifugal compressors, engine cylinder piston components, and driver gear pairs.