活塞阳极氧化表面气泡形成的机理及影响

Mechanism for Air-Bubble Formation on Anodized Aluminum Alloy Piston and the Effect of Air-Bubble on Piston Performance

对铝合金阳极氧化区气泡形成的机理、影响和防止措施进行了探讨。在氧化表面常产生并聚集大量气泡(气泡主要是阳极热量集中处形成的水蒸气气泡和氧离子形成的氧气气泡),导致电压较快地增大而易出现“打火”现象,严重影响活塞氧化膜的质量和厚度的均匀性。利用自制脉冲恒流电源等装置,对ZL109活塞顶面硬质阳极氧化过程中气泡的形成、生长进行了研究。结果表明,快速排除活塞顶面氧化过程中的气泡,可以有效地防止“打火”现象,提高氧化膜质量。

The air-bubble formation in the hard anodic oxidation of aluminum alloy (ZL109) pistol was studied using a pulse/galvanostat electric power supply device. The effect of the air-bubble on the performance of the piston made of the Al alloy was investigated. It was found that a great amount of vapor-bubble and oxygen-bubble was generated at the heat-concentration zones of the anodized Al alloy piston, which could greatly damage the quality and uniformity of the oxidation film owing to a sharp increase in the voltage and the accompanied sparking. It was feasible to get rid of the sparking phenomena in the anodizing process of the Al alloy piston by effectively exhausting the air-bubbles generated on the top surface of the piston, which could contribute to increase the quality of the oxidation layer.