无铵助镀剂热浸Zn-0.05% Al合金浴的镀层性能研究

Study on Performance of Ammonium-free Flux of Zn-0.05% Al Alloy Hot-dip Galvanizing

用SEM、EDS、电化学和全浸试验检等方法对比分析了传统氯化锌铵助镀剂和无铵助镀剂两种助镀工艺对镀层性能的影响,以探讨无铵助镀工艺对镀层性能的影响及其作用机理。结果表明;在无铵助镀条件下,镀层厚度与传统助镀条件的相差不大,但得到的合金层组织更为致密,各相层间无明显分界线和裂纹,在一定程度上抑制了脆性相ζ层的生长,有利于塑性相δ层的生长;在提高镀层的黏附性的同时也提高了镀层的耐腐蚀性,其耐腐蚀性能较传统氯化锌铵助镀提高1倍左右。

The influences of traditional plating agent and ammonium-free plating agent on the performance of coating were studied using SEM and EDS. Then the function and action mechanism of the ammonium-free plating process was discussed. The results show that under the condation of ammonium-free plating process, the thickness of the zinc coating is almost the same with the traditional plating agent＇s, but the phase structure of ammonium-free plating process is denser, and the bounds of the four phases is breezing with no cracks; Ammonium-free plating agents can retrain the growth of the brittle phase ζ and accelerate the growth of plastic phase δ. The adhesion of the coating with ammonium-free fluxing process is increased significantly, and so the corrosion-resisting properties of zinc coating which is double higher than that of the traditional plating process.