Novel blue diode laser cladding for high-performance nickel-based coatings on copper substrates

The high reflectivity and excellent thermal conductivity exhibited by copper substrates pose considerable challenges for conventional laser cladding techniques aiming to achieve high-performance coatings on their surfaces. In this study, a novel blue diode laser cladding approach was proposed to prepare nickel-based coatings on copper substrates. Under the conditions of a preheating temperature of 200 °C and laser power of 1500 W, a Ni60A coating was successfully fabricated on the surface of pure copper, with metallurgical bonding achieved and no crack defects observed. The average microhardness of the coating ranges from 468 HV0.1 to 775 HV0.1, which is approximately 8.8–14.6 times greater than that of the copper substrate. Furthermore, the wear resistance of the coating is approximately 3.6–4.7 times higher than that of copper at 25 °C, and approximately 3.8–5.4 times higher at 300 °C. The performance of the coating exhibit gradient variations in the cladding direction. Consequently, the challenges posed by the high laser reflectivity and the need for a high preheating temperature of copper substrate have been effectively overcome through the utilization of a blue laser cladding, facilitating the industrial-scale preparation of large-area coatings on copper components.