电解液中Ca^(2+)、Mg^(2+)对ZAlSi12Cu2Mg1微弧氧化陶瓷膜表面形貌的影响

Effects of Ca^(2+) and Mg^(2+) in the electrolyte on the SEM images of the MAO coatings prepared on the ZAlSi12Cu2Mg1 alloy

在Al2O3陶瓷的烧结过程中,添加剂MgO和CaO起着极其重要的作用。本文主要研究在微弧氧化过程中,电解液中加入Ca2+、Mg2+后,ZAlSi12Cu2Mg1合金微弧氧化陶瓷膜表面形貌的变化。SEM结果表明:微弧氧化陶瓷层由大小不相等的表面具有放电气孔的颗粒组成,在基础电解液中加入Ca2+后,生成的陶瓷膜层与添加Mg2+的电解液中生成的陶瓷膜层相比,表面较平整、陶瓷颗粒形状比较均匀,且表面有大约2μm的树枝状晶体,但还没有完全生长。微弧氧化膜层表面有明显的热裂裂纹存在,且这些裂纹穿过放电气孔。膜层表面不均匀的分布有细小的浅色颗粒。

In the process of the sintering of the Al2O3 ceramics, additions of MgO and CaO play important roles. In this paper, the changes of the surface morphology of the MAC） coatings when adding Ca^2＋ , Mg^2＋ in the electrolyte on ZAlSi12Cu2Mg1 alloys were investigated. The QUANTA-400 Scanning Electron Microscope was employed to observe the surface morphology of the MAC） ceramic coatings. The result of the SEM showed that, the MAC） coatings were consisted of ceramic grains with discharge pores on it and their size were very different. Compared with the ceramic coatings oxided in the electrolyte with Mg^2＋ ,the surface of the coatings prepared in the electrolyte with Ca^2＋ were more smooth, the shape of the grains of the ceramic were uniformity, and there were some branch-shaped crystals, which sizes were about 2 μm, but they did not grow entirely, and there were obvious cracks in the coatings, and the cracks through the discharge pores. There were some pale-colored grains on the surface of the coatings.