关键词: 微弧氧化；双极性脉冲电源；氧化膜；LY12铝合金

Abstract:

Experimental studies on micro arc oxidation (MAO) machining LY12 aluminum alloy were carried out using bipolar square pulse power source designed by ourselves, and comparison studies on the film thickness and hardness of the oxidation ceramic film were performed,which was formed with different pulse mode produced by different power source pulse, such as square pulse, positive and negative alternation square pulse, and positive sine wave. Compared with the films formed with positive square pulse power and positive sine wave power source, it is found that the thickness of ceramic film generated with the bipolar square pulse power source is thicker, and the bonding between oxidation film and matrix is compact and strong, and film hardness is higher. Experiments show the bipolar square pulse power supply has better film characteristics. Moreover, the working mechanism on the oxidation of the negative pulse was analyzed.

Key words: micro arc oxidation (MAO), bipolar pulse power source, oxidation film, LY12 aluminum alloy