电泳-电沉积制备镍-钴-氧化铝纳米复合镀层及其性能

摘要

Ni–Co–Al2O3 nanocomposite coating with a high content of Al2O3 was prepared as follows: a uniform Al2O3 film with an average particle size of 20 nm was electrophoretically deposited first on pure copper substrate, and then a Ni–Co alloy coating was electrodeposited on it. The micro-morphology and composition of the composite coating were analyzed using scanning electron microscopy and energy-dispersive spectroscopy. The influence of Al2O3content in coating on microhardness and wear resistance of the coating were studied. The results showed that Ni–Co–Al2O3 composite coatings with different Al2O3 contents can be obtained by controlling electrophoretic deposition time. The overall performance of Ni–Co–Al2O3composite coating is better than that of Ni–Co alloy coating and Ni–Al2O3 composite coating. The Ni–Co–Al2O3composite coating containing ca.30vol% Al2O3 obtained by electrophoretic deposition for 120 s features compact structure, high microhardness, and the best wear resistance.%先采用电泳沉积工艺在紫铜表面均匀沉积粒径为20 nm的Al2O3薄膜，然后通过电沉积在Al2O3沉积层表面得到Ni–Co合金，最终得到具有较高Al2O3含量的Ni–Co–Al2O3纳米复合镀层。采用扫描电镜和能谱仪分析了复合镀层的微观形貌和组成，并研究了镀层中Al2O3含量对镀层显微硬度和耐磨性的影响。结果表明，通过改变电泳沉积时间可制得Al2O3含量不同的Ni–Co–Al2O3复合镀层。Ni–Co–Al2O3复合镀层的综合性能优于Ni–Co合金镀层和Ni–Al2O3复合镀层。当复合镀层中纳米Al2O3粒子的体积分数约为30%(电泳沉积时间120 s)时，镀层组织致密，显微硬度较高，耐磨性最佳。