论文部分内容阅读
将工业纯铁分别在510℃的Zn-11%Al、Zn-11%Al-1.5%Mg、Zn-11%Al-3%Mg和Zn-11%Al-4.5%Mg合金熔池中进行不同时间的热浸镀,使用X射线衍射仪、扫描电子显微镜、能谱仪等仪器设备,研究Mg含量对Zn-11%Al合金镀层凝固组织和镀层中Fe-Al合金层生长的影响.结果表明:Zn-11%Al合金镀层凝固组织由富Al相和Zn/Al二元共晶组成;随着Zn-11%Al-x%Mg合金中Mg含量的增加,合金镀层的凝固组织中逐渐出现Zn/Al/Mg Zn2三元共晶、块状Mg Zn2相和Al/Mg Zn2二元共晶.四种合金镀层中合金层主要由Fe2Al5Znx和Fe Al3Znx相组成,合金层的厚度随浸镀时间的增加而增加,Mg含量的增加使Fe-Al合金层生长速率指数和生长速率降低.在Zn-11%Al合金镀层中Fe-Al合金层形成的初期,可形成致密稳定的Fe-Al化合物层;热浸镀120 s后,扩散通道的移动使Fe-Al化合物层失稳破裂.Zn-11%Al-x%Mg合金中Mg元素可明显推迟液Zn进入镀层中Fe-Al合金层的时间,使Fe-Al合金层更加稳定和致密.
Industrial pure iron was varied in Zn-11% Al, Zn-11% Al-1.5% Mg, Zn-11% Al-3% Mg and Zn-11% Al-4.5% Mg alloy baths at 510 ° C The effects of Mg content on the solidification microstructure and the growth of Fe-Al alloy layer in Zn-11% Al alloy coating were studied by X-ray diffractometry, scanning electron microscopy, energy dispersive spectrometer and so on.The results show that : The solidification microstructure of Zn-11% Al alloy coating consists of Al-rich phase and Zn / Al binary eutectic. With the increase of Mg content in Zn-11% Al-x% Mg alloy, the solidification microstructure of alloy coating gradually appears Zn / Al / Mg Zn2 ternary eutectic, bulk Mg Zn2 phase and Al / Mg Zn2 binary eutectic alloy layer of the four alloy coating mainly composed of Fe2Al5Znx and FeAl3Znx phase, the thickness of the alloy layer with the immersion time , And the increase of Mg content decreased the growth rate and the growth rate of Fe-Al alloy layer.In the initial stage of the formation of Fe-Al alloy layer in Zn-11% Al alloy coating, a dense and stable Fe-Al compound Layer. After 120 s hot-dip plating, the movement of the diffusion channel destabilizes the Fe-Al compound layer, and the Mg element in Zn-11% Al-x% Mg alloy obviously delays the entry of liquid Zn into the Fe-Al alloy layer Time, make Fe-Al alloy layer more stable and dense.