Effect of electroless for 7075 aluminum alloy on microstructure and properties of Ni-P alloy coatings
ZHU Hui-yi1,2, MAO Jian-hui1, YIN Ling-peng1
1. School of Mechanical and Electrical Engineering, Quzhou College of Technology, Quzhou 324000, Zhejiang, China; 2. College of Mechanical and Vehicle Engineering, Chongqing University, Chongqing 400030, China
Abstract：Surface treatment directly affects mechanical properties and corrosion resistance of 7075 aluminum alloy. The base material used in the experiment was 7075-T6 aluminum alloy, the Ni-P coating with a certain thickness was fabricated by electroless nickel (EN) on the surface of smooth substrate surface, and the coating thicknesses were 3.64, 5.87 and 7.33 μm, respectively. The effect of characteristics and thickness of the coating on mechanical and corrosion properties of 7075-T6 aluminum alloy was analyzed using methods such as scanning electron microscope (SEM), X-ray diffraction (XRD), hardness test and electrochemical workstation. The experimental results showed that electroless nickel plating could form Ni-P layer on the surface of 7075 aluminum alloy, and the Ni-P coating was observed by SEM, which was tightly bonded to the substrate. The XRD analysis showed that the coating presented a microcrystalline morphology, and the coating showed good adhesion through observation by Rockwell-C indentation test. In terms of mechanical properties, the fatigue strength decreased slightly, and the elongation decreased more obviously, while the hardness, yield strength, tensile strength and elastic modulus were significantly improved. In terms of corrosion resistance, the Ni-P coating could significantly improve the corrosion resistance of the surface for 7075-T6 aluminum alloy by one order of magnitude, and the base material can be better protected.
祝惠一, 毛建辉, 尹凌鹏. 7075铝合金化学镀对镍磷合金镀膜组织和性能的影响[J]. 中国冶金, 2022, 32(1): 58-63.
ZHU Hui-yi, MAO Jian-hui, YIN Ling-peng. Effect of electroless for 7075 aluminum alloy on microstructure and properties of Ni-P alloy coatings[J]. China Metallurgy, 2022, 32(1): 58-63.
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