Restoration of pure copper motor commutator for aviation by laser powder deposition

The deep grooves often appeared in the commutator of aircraft photoelectric radar motors due to the brush's wear, which resulted in decreased of electrical performance and commutation accuracy, affecting combat performance. Here, we present that the blue laser cladding could be used to repair the faulty part of the pure copper motor commutator. The microstructure, microhardness, wear resistance, and electrical conductivity results show that the surface of the coating was smooth and there were no pores, cracks, and other defects in the bonding interface. There was an apparent transition zone between the matrix and the cladding layer, and a good metallurgical bonding with the matrix was formed. Compared with the matrix, the average microhardness and wear resistance of the cladding layer were increased by 2.22 times and 2.37 times, better than the copper substrate, while the electrical conductivity of the repaired layer was still about 97.7% of that of the pure copper substrate. Our study demonstrates the potential of applying the optimum technological parameters of laser cladding repair to provide the theoretical and experimental basis for mass repair.