处理时间对铝合金微弧氧化陶瓷膜特性的影响

为了研究恒定电流密度下铝合金微弧氧化陶瓷膜的特性随处理时间的变化规律,在工作电流密度设定为25 A/dm2时制备了处理时间分别为1、3、5、10、20、30 min的样品共6块,并采用光学显微镜、显微硬度计、表粗糙度测量仪和SEM等手段对氧化陶瓷膜的形成机理进行了研究.结果表明,陶瓷膜表面呈圆饼状结构,圆饼的中心存在一个放电通道;膜的厚度、表面粗糙度、圆饼和放电通道的直径随处理时间线性增加;陶瓷膜的显微硬度与处理时间密切相关.

Effect of treatment time on MAO coating characteristics of aluminum alloy

In order to study the microarc oxidation(MAO) coating characteristics of aluminium alloy at constant current density,six samples with different treating time of 1,3,5,10,20 and 30 min were fabricated at the constant current density of 25 A/dm2.The optical microscopy with a CCD camera,the microhardness tester,the surface roughness measurement tester and the scanning electron microscopy(SEM) were employed in studying the forming mechanism of the MAO coating.The results show that the surface morphology of MAO coatings is characterized by a pancake structure wherein the centre of each pancake exists a discharge channel;the coating thickness,surface roughness,as well as the diameters of the discharge channels and the pancakes increase linearly with the increasing treatment time;and the coating microhardness is closely relative to the treating time.