锡粉含量对无铬锌铝涂层性能的影响研究

Effect of Sn Powder Content on Properties of Chromium⁃Free Zinc⁃Aluminum Coatings

为进一步降低锌铝涂层的摩擦系数,在水性无铬锌铝涂层的基础上引入锡粉,通过对涂层的硬度、附着力、抗冲击性、耐盐雾、电化学性能、摩擦系数及微观形貌等方面进行评价分析,探究了不同用量的锡粉对涂层的力学性能、耐蚀性及摩擦学性能的影响。结果表明:锌铝涂层中引入锡粉能有效提升涂层的韧性,当其含量为5%~10%(质量分数)时,涂层的硬度不出现明显下降,且附着力和抗冲击性得到有效提升;锡粉的添加还能改善涂层的润滑性能,降低涂层的摩擦系数,当其含量为10%~20%(质量分数)时,螺纹摩擦系数以及支撑面摩擦系数均可降低至0.15以下;而且,锡粉的加入还可提升涂层的耐蚀性,中性盐雾试验和电化学测试结果均表明,当锡粉含量为10%(质量分数)时涂层的耐蚀性能相对更佳。

To further reduce the friction coefficient of zinc⁃aluminum coatings,tin(Sn)powder was introduced into waterborne chromium⁃free zinc⁃aluminum coatings.The coatings were evaluated and analyzed in terms of hardness,adhesion,impact resistance,salt spray resistance,electrochemical properties,friction coefficient and micro morphology.The impact of varying amounts of Sn powder on the mechanical proper⁃ties,corrosion resistance and tribological performance of the coatings was investigated.Results showed that the introduction of tin powder into zinc⁃aluminum coatings effectively enhanced the toughness of the coatings.When the added amount of Sn powder was 5%~10%(mass frac⁃tion,the same below),the hardness of the coatings did not decrease,and both adhesion and impact resistance were significantly improved;the addition of Sn powder was also found to improve the lubrication performance of the coating,reducing its friction coefficient.When the content of Sn powder reached 10%~20%,both the thread friction coefficient and the support surface friction coefficient were reduced to below 0.15.More importantly,the introduction of Sn powder was found to enhance the corrosion resistance of the coating.Results from neutral salt spray tests and electrochemical testing indicated that the coatings exhibited relatively better corrosion resistance when the Sn powder content was 10%.