脉冲电流宽度对镁合金微弧氧化过程的影响

发布时间：2018-11-08 20:52

【摘要】：为了揭示脉冲电流宽度对AZ31B镁合金微弧氧化过程的影响规律,利用示波器记录电流波形,借助涡流测厚仪测量陶瓷层厚度,采用扫描电子显微镜观察陶瓷层表面和截面形貌,根据电压变化曲线计算微弧氧化过程能量消耗。结果表明,随着脉宽由15μs增至90μs,起弧时间由358 s缩短至25 s,起弧电压先降低后升高并在脉宽30μs时达到最小值183 V;陶瓷层表面放电微孔孔径增大,微孔数量减少,陶瓷层厚度增加但致密度下降;起弧过程能量消耗随脉宽增大先降低后升高,并在脉宽为30μs时达到最小值3.9 k J;陶瓷层生长过程能量消耗随脉宽增大近似成倍增加;单位厚度陶瓷层的生长能耗先降低后平稳增长,同样在脉宽30μs时达到最小值10.2 kJ。
[Abstract]:In order to reveal the influence of pulse current width on the process of micro-arc oxidation of AZ31B magnesium alloy, the current waveform was recorded by oscilloscope, the thickness of ceramic layer was measured by means of eddy current gauge, and the surface and cross-section morphology of ceramic layer was observed by scanning electron microscope. The energy consumption of the micro-arc oxidation process is calculated according to the voltage variation curve. The results show that with the pulse width increasing from 15 渭 s to 90 渭 s, the starting time is shortened from 358 s to 25 s, the starting voltage decreases first and then increases, and reaches the minimum 183V when the pulse width is 30 渭 s. The discharge pore diameter of ceramic layer increases, the number of micropores decreases, the thickness of ceramic layer increases but the density decreases, and the energy consumption decreases first and then increases with the increase of pulse width, and the minimum value is 3.9 kJ when the pulse width is 30 渭 s. The energy consumption of ceramic layer increases approximately with the increase of pulse width, and the energy consumption of ceramic layer per unit thickness decreases first and then increases steadily, and reaches a minimum of 10.2 kJ. at pulse width of 30 渭 s.
【作者单位】：西安理工大学;
【基金】：国家自然科学基金资助(51071121) “十二五”国家科技支撑计划资助(2011BAE22B05)
【分类号】：TG174.4

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