摘要
应用 Ｓ Ｅ Ｍ、 Ｅ Ｄ Ｘ、 Ｘ Ｒ Ｄ 及 Ｘ Ｐ Ｓ 等技术研究了无水洗电镀锌钢板表面黑变膜形貌、组成与结构，并对黑变的原因进行了讨论。结果表明：黑变膜厚度约为７０ ｎｍ ，它由 Ｚｎ Ｏ、 Ｚｎ（ Ｏ Ｈ）２ 、 Ｚｎ５（ Ｃ Ｏ３）２（ Ｏ Ｈ）６ 或３ Ｚｎ（ Ｏ Ｈ）２· Ｚｎ Ｃ Ｏ３· Ｈ２ Ｏ 及微量 Ｐｂ Ｏ 组成，但膜表层的 Ｚｎ 是以 Ｚｎ Ｏ 形态存在，而膜内层则以非化学计量化合物 Ｚｎ Ｏ１ Ｘ 形态存在。黑变的原因主要是由于锌的阳极活性溶解作用和杂质 Ｐｂ 及其沉淀物的阴极去极化作用。另一方面，镀锌层表面的低ｐ Ｈ 值和 Ｐｂ 以溶解—再沉积的方式促进了锌层腐蚀的发生和发展。同时发现黑变显示的颜色是由镀锌板表面形成的腐蚀产物膜上产生的光的干涉现象所致。
The morphology, composition and structure of black tranished film on the surface of electrodeposited zinc steel sheet without water cleaning were investigated by means of SEM, EDX, XRD and XPS, and the formation of black tarnished film was also discussed. The experimental results demonstrated that black tamished film was about 70 nm thick, and it was composed of ZnO\, Zn(OH) 2、Zn 5(CO 3) 2(OH) 6) or 3Zn (OH) 2·ZnCO 3·H 2O ) and trace PbO. Zine existed as ZnO in the upper layer and as non-stoichimetric compound ZnO 1 X in the base layer of the black tarnished film. The black tarnished film of zinc deposit was caused by anodic activated dissolution of zinc and cathodic depolarization of Pb impurities and their sediments. On the other hands, the low pH value and dissolution-redeposition of Pb impurities on the surface of the deposit may accelerate the occurrence and development of corrosion of zinc. And it was found that the color shown was the effect of light interference of corrosion product film formed on the surface of the electrodeposited zinc steel sheet.
出处
《电镀与涂饰》
CAS
CSCD
1999年第3期5-10,共6页
Electroplating & Finishing
基金
国家"九五"重点科技攻关课题
