2021表面工程国际会议(第8届) (ICSE 2021)

   With the aim of remanufacturing high-value parts of shield tunneling machines (e.g. sealing track), Fe-based composite coatings were prepared by collaborative modification with Nano-TiC and Nano-CeO₂ by laser cladding. The cladding composite powder with micro-nano structure was prepared by mechanical milling, and the microstructure, phase composition, microhardness and wear properties of the Fe-based coatings were studies. The results show that the Nano-TiC can effectively eliminate the defects such as cracks and holes and promote the transformation of columnar dendritic to petal-like dendritic. The size, morphology and agglomeration degree of TiC phase in coatings were significantly affected by the Nano-TiC content. With the addition of Nano-TiC (from 5% to 15%), the hardness of modified coatings decreases gradually and the wear volume decreases first and then increases (lowest for 10%Nano-TiC). Based on the above research, the influence of the content of nano-CeO₂ was further studied. The agglomeration degree of Nano-TiC and the wear assistance of the coatings are significantly affected by the content of Nano-CeO₂. Compared with the Fe55 coating, the wear volume of Fe55+10%Nano-TiC+1%Nano-CeO₂ coating is decreased by about 49%. Moreover, the Fe-based coating is abrasive wear and fatigue wear by observing the wear surface morphology. This paper provides experimental guidance for application of the Fe55 coating in wear environment.