Laser cladding remanufacturing of aircraft landing gear based on 30CrMnSiNi2A steel

Abstract

Remanufacturing landing gear is of great importance due to its vital function for the aircraft. The 30CrMnSiNi2A steel surface is remanufactured through laser cladding based on the actual service environment of landing gear. Six Ni-based wolfram carbide (WC) composite coatings with different proportions are prepared during the experiment. The microstructure, phase composition, microhardness, wear and corrosive resistance of the coatings are analyzed considering actual working conditions. Results show that the remanufactured coating well bonds with the substrate metallurgically without cracks and pores on the surface, except for the coating with 25 wt% WC content. The wear and corrosive resistance of the repaired coating greatly improve compared with those of substrate. It suggests that corrosive resistance for coating and substrate is different especially in a salt spray environment. The coating that is well-bonded with the substrate and has a compact structure can be obtained when the WC content is 20 wt%. In this case, the coating is characterized by an optimal hardness, wear and corrosive resistance. The coating microhardness is 542HV0.2. The weight loss of coating only accounts for 25.92 % of that of the substrate under dry friction. The electrochemical corrosion rate is 0.0025 mm/a, accounting for 1.37 % of that of the substrate. The surface of coating exhibits a good performance under a salt spray environment for 1000 h. This experiment aims to realize the remanufacturing of landing gear and hence provide a reference in its practical application.