为了获得具有更好耐腐蚀性能的机械镀镀层，将锌粉和钛粉按照质量比15∶11混合，采用机械镀的方式在钢铁件表面制备Zn-Ti复合镀层。施镀时用氟化氢铵作为钛粉的活化剂；硫酸亚锡引导沉积并作为锌粉颗粒及钛粉颗粒间的连接填充材料；EDTA、乌洛托品和OP-10螯合沉积形成镀层。以金相显微镜(OM)、扫描电子显微镜(SEM)观察分析镀层的形貌及组织结构，划线划格检验镀层无翘起和脱落，利用电化学方法和中性盐雾试验检测镀层的电化学性能和腐蚀状况。结果显示：机械镀Zn-Ti复合镀层覆盖完整，镀层表面粗糙。镀层与基体结合牢固，镀层中颗粒间结合良好。锌粉及钛粉成镶嵌堆叠状，金属锡主要在镀层和基体间、各颗粒之间起连接作用，复合镀层的自腐蚀电位Em为-1 096 mV，镀锌层自腐蚀电位为-1 240 mV。极化电阻复合镀层为7.07 Ω·cm2，镀锌层为5.11 Ω·cm2。盐雾试验720 h，复合镀层红锈面积约为镀锌层的15%。镀层内金属颗粒之间以机械结合，镀层与基体及金属颗粒之间能够明显观察到金属锡界限，镀层没有合金过渡存在，致密的镀层有利于耐腐蚀能力的提高。在盐雾试验中复合镀层相较镀锌层有更少的白锈和红锈，完整紧实的白锈能够减缓基体腐蚀。
In order to obtain mechanical plating with better corrosion resistance, zinc powder and titanium powder were mixed in a mass ratio of 15∶11 to make the Zn-Ti composite coating on the surface of the steel body by mechanical plating.Ammonium bifluoride was used as the activator of titanium powder particles; stannous sulfate guided the deposition and acted as the filling material on the connection between zinc powder particles and titanium powder particles; EDTA, urotropine and OP-10 were used for chelating deposition to form a plating layer.Metallographic microscope(OM), scanning electron microscope(SEM)were used to analyze the morphology and microstructure of the coating.Scribing the coating to check whether the coating was warped or peeled.Electrochemical method and neutral salt spray test were used to detect the electrochemical performance and corrosion status of the coating.Results showed that the Zn-Ti composite coating had complete coverage, the surface was rough.The coating firmly adhered to the substrate well.The particles in the coating combined well.Zinc powder and titanium powder were inlaid and stacked.Metal tin mainly connected between the coating and the substrate and among the particles.The self-corrosion potential Em of the composite coating was-1 096 mV, and that of the zinc coating was-1 240 mV.The polarization resistance of the composite coating was 7.07 Ω·cm2, and that of the galvanized layer was 5.11 Ω·cm2.In the salt spray test of 720 h, the red rust area of the composite coating was about 15% of the zinc coating.The metal particles of the coating were mechanically bonded.The metal tin boundary was clearly observed between the coating and the substrate and among the metal particles.There was no alloy transition of the coating, and the dense plating particles were conducive to the improvement of corrosion resistance.In the salt spray experiment, the composite coating had less white rust and red rust than the zinc coating, and intact and compact white rust can slow substrate corrosion.
