激光辅助低压冷喷涂 CNTs/Cu 复合涂层工艺研究

In order to meet the needs of repair and surface modification of copper contacts in high voltage switchgears, carbon nanotubes (CNTs)/Cu composite coating is prepared on the surface of Cu substrate by laser^-assisted low pressure cold spraying with CNTs as reinforcing phase and Cu as bonding phase. First, the surface of CNTs is metallized by electroless^-plating of copper to improve the density of CNTs and the interfacial bonding between CNTs and Cu. Then, the spraying distance, scanning speed, and laser irradiation power are optimized. Finally, the microstructure of the composite coating is analyzed by energy dispersion spectroscopy (EDS) and scanning electron microscope (SEM). The results show that the interfacial bonding between the coating and the substrate is the best when the spraying distance is 15 mm. With the increase of scanning speed, the internal of the coating has relatively good compactness and coating/interface bonding state, and the surface of the coating is smooth. With the increase of laser irradiation power, the thickness and width of the coating first increase and then decrease, and the coating thickness reaches the maximum at 800 W. Due to the softening effect of laser heating and the protective effect of copper films on the surface of CNTs, CNTs can be evenly dispersed in the composite coating and maintain the structural integrity.