电参数对LY12铝合金微弧氧化成膜影响规律的研究

Research on Effect law of Electric Parameters on Properties of Micro-Arc Oxidation Coatings on LY12 Aluminum Alloy

自制了大功率微弧氧化脉冲电源,利用该电源对LY12铝合金进行了微弧氧化加工实验,并采用膜层测厚仪、显微硬度仪、扫描电子显微镜(SEM)和X射线衍射仪(XRD)等设备检测生成膜层的厚度、形貌和相结构,进而研究电源的正脉冲幅值、频率、正脉冲的占空比等参数对生成膜层性能的影响规律。结果表明:随着正脉冲幅值的增大,氧化膜的厚度和硬度增大,表面粗糙度值先增大后减小,γ￣Al2O3的衍射峰逐渐降低,α￣Al2O3的衍射峰逐渐增强;增大正脉冲的占空比,使氧化膜的厚度、表面粗糙度值及硬度均增大;频率达到500 Hz时,膜层厚度达到最大。

Experimental studies on micro-arc oxidation machining LY12 aluminum alloy were carried out using bipolar square pulse power source designed by ourselves. The effect law of electric parameters, such as the positive pulse aplitude,frequency, the posilive pulse duty, on properties of micro-arc oxidation coatings is studied by thickness test, micro-hardness test, SEM, XRD. The results show that the coating＇s thickness, hardness, and the content of γ-AlO3 increase and the content of α-AlO3 decrease, surface roughness increase at firs and then increasing, with the positive pulse amplitude decrease. With the positive pulse duty cycle increasing, the coating＇s thickness, roughness and hardness increases. When the frequency is 500 Hz, the coating＇s thickness is maximum.