LY12铝合金微弧氧化的尺寸变化规律

研究了ＬＹ１２铝合金微弧氧化过程中工件尺寸变化规律，并初步分析了氧化膜生长机理。氧化膜经过一段时间的线性增长后，生长速度逐渐降低。氧化初始阶段向外生长为主，氧化膜达到一定厚度后，工件外部尺寸不再增加，而逐渐转向基体内部生长。氧化膜分为疏松层和致密层两层结构，致密层最终可占到总膜厚的７５％以上，打磨掉表面疏松层后，工件基本上能保持原始尺寸。

SIZE CHANGE OF LY12 ALUMINUM ALLOY IN PROCESS OF MICROARC OXIDATION

The regularity of size change of samples in process of microarc oxidation of LY12 aluminum alloy was studied, and the formation mechanism of the oxidation film was simply discussed. The growth rate of film decreases gradually after some time with linear growth. The oxidation mainly takes place on the external surface in the initial stage and the geometry size of samples increases, but after this stage, when the oxide film with a certain thickness is formed, the process of oxidation shifts onto substrate. The total thickness of the film continuously increases, but the geometry size of samples would merely change. The oxide film contains loose layer and compact layer, the compact layer can finally be more than 75% of total thickness of film. After the loose layer of surface is ground off, the sample would nearly maintain the same size as the original one.