铝元素对锌镀层耐蚀性的影响

研究了用复合电沉积法制备的锌铝镀层在微酸性腐蚀介质中的耐蚀参力。失重法，电化学性能试验证明：镀液中的氢氧化铝也能改善镀层的耐蚀性，但不如铝粉的作用显著。电子探针和等离子光谱显示含氢氧化铝和含铝粉镀层中的铝呈均匀分布状态，但前者铝的含量为５０ｐｐｍ，后者相对较多０．１５％。Ｘ－射线衍射法揭示溶液中的氢氧化铝能使镀层的结晶细致，晶面择优取向程度增加。当镀液中含有铝粉时，所得镀层的结构则成为层状，且结晶

The Effect of Aluminium Element on Corrosion Resistance of Electrodeposited Zinc Coating

The effect of aluminium element on corrosion-resistant electrodeposited Zinc coating has been investigated in this paper. It is discovered that Al(OH)3 colloid in electrolyte can improve corrosion resistance of the coating, but is not as effective as aluminium particles through the experiments on the weight loss method and the electrochemical test.EPMA and ICP tests showed Al element in coatings containing Al(OH)3 and Al particles are uniformly scattered, but in the former test the aluminium content is 50ppm, while in the latter 0. 15% (w/w). X-ray diffraction testified that Al (OH)3 colloid could make the crystal grains of the coating finer with higher degree of the preferred orientation. The crystal structure of coating obtained from the solution containing Al particles became stratified with much finer in crystallization and preferred orientation. Therefore, Al (OH)3 colloid and Al particles are able to increase degree of the preferred orientation of crystal planes, resulting in improvement of the corrosion resistance of coatings.