The effect of LPBF scanning angles on the forming quality, wear resistance, and corrosion resistance of the molten layer in CuSn12Ni2 wind turbine bearing bushings
摘要
To enhance the wear resistance and corrosion resistance of 42CrMo bearing steel and extend the service life of sliding bearing bushings in wind turbine gearboxes, this study used Laser Powder Bed Fusion (LPBF) technology to prepare a CuSn12Ni2 molten layer on the surface of 42CrMo bearing steel. Preliminary melting process parameters were determined through orthogonal experiments, and a Greenwood-Tripp (G-T) contact model was established for load analysis. Electrochemical corrosion tests were conducted in a 3.5% sodium chloride (NaCl) solution. Four laser scanning angles (0°, 45°, 67°, and 90°) were tested to analyze the density, microstructure, hardness, friction wear, and corrosion resistance of the molten layers. Results showed that as the scanning angle increased, the overall melting quality first improved and then declined, with 67° proving optimal for achieving high density, high hardness, and minimal porosity. Under a 40 N load, the sample at 67° exhibited the best relative wear resistance (1.35), with abrasive and oxidative wear as the main mechanisms. In the NaCl solution, the 67° sample showed fine and sparse corrosion pits. Its high density and uniformly distributed Sn and Ni elements formed a continuous passive film that effectively blocked Cl− ion penetration. Polarization curves and Bode plots confirmed the corrosion resistance order: 67° > 45° > 90° > 0°. Comprehensive analysis indicated that the 67° scanning angle significantly improved the coating’s performance by optimizing track overlap, reducing defects, and promoting uniform microstructure formation. This research provides theoretical guidance and process references for applying LPBF technology to manufacture wind power sliding bearing bushings in low-speed, heavy-load, and corrosive environments.