Tribological properties of laser in situ textured ductile cast iron deposited with composite coating

This study systematically explores the friction and wear reduction mechanism under the synergistic effect of composite coating and composite micro-texture on ductile cast iron. The preparation process of the composite coating is optimized by using polytetrafluoroethylene (PTFE) as the base material and nano-alumina as the reinforcing agent. The composite micro-texture is efficiently fabricated by using a picosecond laser. Dry friction experiments show that the coating effectively improves the anti-friction performance of the ductile cast iron surface, and the added nano-alumina significantly enhances the wear resistance of the coating. The laser processing increases the hardness of the ductile cast iron surface, and the fabricated micro-texture can effectively store the coating and capture wear particles, the fabricated micro-texture can also slowly release the coating during subsequent friction processes, ensuring a low coefficient of friction (COF) and wear over a long friction time. Compared with the original samples, the average COF and wear mass of ductile cast iron with composite coating and composite micro-texture are decreased by 77% and 93.8%, respectively.