镁合金微弧氧化的负载模型及仿真分析

Equivalent Load Model and Simulation Analysis of Micro-Arc Oxidation of Magnesium Alloy

为了确定镁合金微弧氧化负载对电源形式及参数的要求,基于电化学和电弧物理理论,对单极性和双极性脉冲输出方式下的负载波形进行分析,建立了负载等效电路模型。微弧氧化负载呈现极强的电容性,其负载模型可简化为1个电容和2个电阻等效的一阶RC系统。通过构造电阻可调的强制放电回路,用matlab软件对负载波形曲线进行参数拟合,对等效电路简化模型参数进行了定量分析。所得模型中电容和电阻的数值与计算机仿真结果相符。

The load waveforms for micro-arc oxidation(MAO) of magnesium alloy under single and double polarity pulse output modes were analyzed based on electrochemical and arc physical theories so as to determine the requirements for the output modes and electric parameters of power supply in MAO process.The equivalent circuit model of the MAO load was established.Moreover,The parameters of the simplified equivalent ringing circuit(RC) model were quantitatively analyzed by fitting the load waveform curves with Matlab software while the signal data were collected under a new pulse output mode of power supply with a forced and adjustable discharge loop.Results indicate that the load waveforms for micro-arc oxidation of Mg alloys are highly capacitive,and corresponding electric circuit model can be simplified as a first-order RC system with one capacitance and two resistances.Besides,the capacitance and resistance based on as-established model well conform to relevant computed simulation results.