从不同浸泡时间拍摄的纯锌的光学图像如图 4 所示。所有样品在浸泡 168 小时后仍显示出金属光泽（图 4（a-f））。 随着浸泡时间的延长，样品表面部分被白色沉淀物覆盖（图 4（g 和 h）），这可能是由于浸泡过程中腐蚀产物的沉淀。 此外，表面没有表现出明显的变化，并且在浸泡过程中没有严重腐蚀的迹象。

Optical images of pure Zn taken from different immersion times are shown in Fig. 4. All samples still showed metallic luster after immersion up to 168 h (Fig. 4(a–f)). With the extension of immersion time, the sample surfaces were partially covered by whitish precipitates (Fig. 4(g and h)), which could be attributed to the precipitation of corrosion products during immersion. Besides, the surfaces did not exhibit significant changes and there was no sign of severe corrosion during the immersion.