Fabrication of Microcolumn Arrays Using Through-Mask Electrochemical Micromachining on the 42CrMo Alloy Steel

Abstract

Studies have shown that surface texture can improve lubrication state and reduce friction and wear. The cold pressing process of micro-units can prepare surface textures at low cost, in large quantities, and with high efficiency, but the micro-pillar array mold required for the cold pressing process is difficult to prepare. In this study, the influence of mask electrochemical processing parameters on the height and height uniformity of the micropillar array was studied by orthogonal experiment on the 42CrMo alloy steel. Four main factors are designed in the orthogonal experiment, namely voltage, duty cycle, frequency, and mask spacing, and each factor is set to three levels. The results of the range analysis show that: voltage and duty cycle are positively correlated with the height of the microcolumn, but negatively correlated with uniformity, and when the duty cycle is 50%, the uniformity of the microcolumn decreases sharply; The height and uniformity of the microcolumns increase with the increase of mask spacing. The height of the microcolumn is positively correlated with the frequency, and the uniformity of the microcolumn first increases and then decreases with the increase of frequency. Therefore, in order to meet the height and uniformity requirements at the same time, the grey correlation analysis method was used to obtain the optimal processing parameters: 35 V (voltage), 30% (duty cycle), 300 um (spacing), and 5 kHz (frequency). The average height of the microcolumns prepared by this parameter is 57.632 um and the microcolumn has excellent high uniformity.