铝合金微弧氧化脉冲宽度对陶瓷膜耐蚀性及能量消耗的影响

Effect of Pulse Width on Corrosion Resistance and Energy Consumption of Micro-Arc Oxidation Ceramic Coating of Aluminum Alloy

为了进一步明确脉冲宽度对铝合金微弧氧化陶瓷层耐蚀性及能量消耗的综合影响,在恒峰值电流控制模式下,以不同脉冲宽度在6061铝合金表面制备了微弧氧化陶瓷膜,采用扫描电镜观察陶瓷膜形貌,采用厚度仪及粗糙度仪测试陶瓷膜厚度及粗糙度,采用极化曲线分析陶瓷膜的耐蚀性及微弧氧化的能量消耗;研究了脉冲宽度对陶瓷膜厚度、耐蚀性能及能量消耗的影响。结果表明:随脉冲宽度的增加,阴阳极间电压增速变快,陶瓷膜厚度增加,微孔数量减少,微孔孔径增大,陶瓷层表面粗糙度增大;随脉冲宽度的增加,陶瓷层的耐蚀性能先增强后减弱,在脉冲宽度为80μs时为最好;随脉冲宽度的增加,阴阳极间的能量消耗近似成倍增加,单位厚度陶瓷膜所消耗的能量增幅较小。

Ceramic coatings were prepared on 6061 Al alloy substrate by micro-arc oxidation under different pulse width in constant peak current mode.The morphology of as-prepared micro-arc oxidation coatings was observed with a scanning electron microscope,while their thickness and surface roughness were measured with a hardness meter and a surface roughness meter.The corrosion resistance of the micro-arc oxidation coatings and the energy consumption for micro- arc oxidation were analyzed by electrochemical method.Furthermore,the effect of the pulse width on the thickness and corrosion resistance of the micro- arc oxidation ceramic coatings as well as the energy consumption for micro-arc oxidation was investigated.Results indicated that,along with the increase of the pulse width,the potential between the cathode and anode tended to rise more rapidly,and the thickness of the micro- arc oxidation coatings tended to increase.Furthermore,increased pulse width also led to decreased amount of the micro-pores and increased pore size and the surface roughness of the coatings.In the meantime,the corrosion resistance of the micro-arc oxidation coatings tended to rise initially and decrease later with increasing pulse width,and it reached the best at a pulse width of 80 μs.Moreover,with the increase of the pulse width,the energy consumption between the cathode and anode was nearly doubled,and the energy consumption per thickness of the ceramic coating tended to increase at lessened pace.