Study on the structure and performance of low-pressure cold sprayed Zn-Al-n(Cu-Ni) coatings on power steel structures

Aiming at the problems of high porosity and insufficient abrasion resistance of traditional hot-dip galvanizing layers, this study proposes a Zn-Al-Cu-Ni composite coating system based on low-pressure cold spraying technology. Through the introduction of Cu-Ni reinforced phase and Al2O3 ceramic reinforced phase, the synergistic optimization of the microstructure, mechanical properties and corrosion protection mechanism of the coating was systematically investigated. optimization. The composition of the coating was characterized, and the comprehensive performance of the coating was evaluated by microhardness test, friction and wear test, and acetate fog test. The results show that the dendritic structure of Cu-Ni alloy can significantly improve the coating density through mechanical interlocking and local solid solution effect. The microhardness of the zinc-aluminum-based coating containing 30 wt% Cu-Ni reaches 71.39 HV0.05, the coefficient of friction decreases to the friction coefficient was reduced to 0.445, and the wear mechanism was changed from adhesive wear to abrasive-fatigue composite mode. The salt spray test showed that the coating did not show base red rust during the 216 h corrosion cycle, and the corrosion product generation rate was 83.3% lower than that of conventional zinc-rich coatings. The corrosion product generation rate was 83.3% lower than that of conventional zinc-rich coatings. The study confirms that the low pressure cold spraying technology can effectively inhibit the oxidation of the material and thermal damage of the substrate through the low temperature solid state deposition characteristics. The constructed multi-phase composite coating has both mechanical strengthening and long-lasting corrosion protection functions, which provides a new solution for the whole life cycle protection of electric power steel structural components.