Microstructures and Properties of Nickel-Aluminum-Bronze Coating by Laser Wire Additive Manufacturing

This study investigates the microstructure, mechanical properties, and corrosion resistance of nickel-aluminum bronze (NAB) coatings fabricated on Q235 steel using laser fused wire additive manufacturing (LFWAM). The coatings were characterized using X-ray diffraction (XRD), electron backscatter diffraction (EBSD), and electrochemical analysis. The main phases identified in the NAB coating are α-phase Cu, κⅠ-phase AlFe₃, and κⅡ-phase AlNi. The microstructure is fine, dense, and uniform, with an average microhardness of 259 HV0.2. The average coefficient of friction and wear rate are 0.317 and 1.694 × 10-6g/(N·m), respectively. Corrosion tests show a corrosion potential of -0.21 V and a corrosion current density of 6.201 × 10-7A/cm². The solid solution of Al and Ni in the coating enhances strength through solid solution strengthening. Grain refinement from Al and the formation of a dense oxide layer, along with the presence of the Ni-rich κⅡ-phase, significantly improve the coating’s strength, wear resistance, and corrosion resistance, contributing to its excellent overall performance.