Al-Si合金Al_2O_3-ZrO_2微弧氧化涂层生长机理研究

Growth Mechanism of Al_2O_3-ZrO_2 Coating Prepared by Micro-arc Oxidation on Al-Si Alloy

为了解决Al2O3微弧氧化层不能满足Al-Si合金使用要求的问题,采用微弧氧化法在Al-Si合金表面制备了Al2O3-ZrO2复合膜层,通过SEM、XRD分析测试手段研究膜层的微观表面形貌、组织结构和相组成.结果显示:微弧氧化初期,陶瓷层生长速率较快且反应速率稳定,反应后期陶瓷层生长速率减缓;陶瓷层微观表面形貌比较均匀,有部分放电微孔和裂纹;陶瓷层与金属基体呈犬牙状交错结合;陶瓷层的主要相组成是t-ZrO2、α?Al2O3、m-ZrO2、γ?Al2O3,其中t-ZrO2为膜层主晶相.并根据实验结果研究了微弧氧化涂层的生长机理.

In order to solve the problem that the single AI2CI3 micro-arc oxlaauon coating can not fit the requirement of A1-Si alloy, the A12 O3-ZrO2 compound ceramic layer was produced on A1-Si alloy by micro -arc oxidation. The microstructure and composition of the coating were investigated by SEM and XRD. The results show that in initial stage of Micro arc oxidation, ceramic layer growth rate is rapidder and the reaction is stable,and in later stage, the growth rate becomes slow. The microscopic surface of ceramic laye is relatively uniform, with some partial discharge pores and cracks; ceramic layer and the metal substrate are hackly staggered combination. The coating phases consist t-AlzOs, a-A12Oa ,m-ZrO2,γ- ZrO2 ,of which t-ZrO2 is the main phase. The growth mechanism of microarc oxidation coating was analyzed by the experimental result.