电源模式对ADC12高硅铝合金微弧氧化膜层组织与性能的影响

Effects of Power Supply Modes on the Microstructure and Properties of Micro-arc Oxidation Coatings Formed on ADC12 High Silicon Aluminum Alloy

目的探究三种电源模式对ADC12高硅铝合金微弧氧化膜层性能的影响,从中选择对其微弧氧化膜层性能较优的电源模式。方法在三种不同电源模式(交流电源、单极性脉冲电源和双极性脉冲电源)的条件下,应用微弧氧化(MAO)技术在ADC12高硅铝合金表面制备了陶瓷膜层,并采用扫描电镜(SEM)、X射线衍射仪(XRD)、显微硬度计、摩擦磨损试验机等手段表征ADC12铝合金微弧氧化膜层的显微组织与性能。结果三种电源模式下微弧氧化膜层中都存在α-Al2O3、γ-Al2O3和Al9Si等物相;双脉冲模式下制备的微弧氧化膜层的致密性最好,厚度为15μm,硬度达到719 HV,摩擦系数为1.2左右,膜层与基体开始脱落的载荷为25.8 N。交流模式下制备的微弧氧化膜层膜厚较低,厚度为9μm,硬度达到698 HV,摩擦系数为1.35左右,膜层与基体开始脱落的载荷为19.5 N。单极性模式下制备的微弧氧化膜层厚度为17μm,但硬度为706 HV,摩擦系数为1.35左右,膜层与基体开始脱落的载荷为13.09 N。结论通过三种电源模式的比较,ADC12高硅铝合金在双极性脉冲电源模式下制得膜层的综合性能较好。

The work aims to study the effects of three power modes on the performance of micro arc oxidation coating on ADC12 high silicon aluminum alloy,so as to select the power mode leading to the better performance of micro arc oxidation coating.Under three different power supply modes(AC power supply,unipolar pulse power supply and bipolar pulse power supply),ceramic coatings were prepared on the surface of ADC12 high silicon aluminum alloy by micro arc oxidation(MAO)technology.The microstructure and properties of micro arc oxidation coating on ADC12 aluminum alloy were characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD),microhardness tester and friction and wear tester.α-Al2O3,γ-Al2O3 and Al9Si phases existed in the micro arc oxidation coating under three power supply modes.The micro arc oxidation coating prepared under double pulse mode had the best compactness,with a thickness of 15μm,a hardness of 719 HV,a friction coefficient of about 1.2,and a load leading to falling of coating and substrate of 25.8 N.The MAO coating prepared under the AC power supply had the lowest thickness of 9μm,a hardness of 698 HV,a friction coefficient of about 1.35,and a load leading to falling of coating and substrate of 15.9 N.The MAO coating under the unipolar mode had a thickness of 17μm,a hardness of 706 HV,a friction coefficient of about 1.35,and a load leading to falling of coating and substrate of 13.09 N.Through the comparison of three power supply modes,the comprehensive performance of the coating on ADC12 high silicon aluminum alloy under bipolar pulse power supply mode is better.