Abstract—

Micro texturing with dimples is one of the most established methods for the enhancement of lubrication and tribological performance. In this work, a novel approach of through-mask electrochemical micromachining is instigated to fabricate high-aspect-ratio circular micro-dimples utilizing a low-cost photoresist (AZ-4903) as mask. Experiments were performed to understand the influence of the applied voltage along with the electrolyte type and concentration on the machining precision and surface characteristics of the generated micro array. The influence of three electrolytes has been studied and it has been experimentally established that 10% NaCl + 10% NaNO₃ is favorable during maximization of the depth of the generated micro-dimples to 39.03 µm whereas undercut is minimized to 15.15 µm by utilizing 20% NaNO₃. The surface quality of the generated micro-dimples has been found to be the finest, i.e. 0.062 µm, for the samples machined with 10% NaNO₃. Patterned arrays containing micro-dimples having maximum depths of 30 μm, 35 μm, and 40 μm were successfully fabricated over a stainless steel (SS304) substrate by using these electrolytes with considerable accuracy and repeatability. The experiments confirm possibility to obtain high-aspect-ratio micro-dimples with the least degree of undercut using this technique. Further, friction test results were analyzed to figure out the alterations in the frictional coefficient of the micro-dimples with different depths as well as with non-dimpled samples.

中文翻译：

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掩膜电化学微加工在微织构表面产生中的实验研究

摘要—

带凹痕的微纹理化是增强润滑性和摩擦学性能的最成熟的方法之一。在这项工作中，提出了一种通过掩模进行电化学微细加工的新方法，以利用低成本的光刻胶（AZ-4903）作为掩模来制造高纵横比的圆形微凹痕。进行实验以了解施加的电压以及电解质类型和浓度对所产生的微阵列的加工精度和表面特性的影响。已经研究了三种电解质的影响，并已通过实验确定，在将产生的微凹坑深度最大化至39.03 µm的过程中，最好使用10％NaCl + 10％NaNO _3，而通过利用20％的蚀蚀将底切最小化至15.15 µm硝酸钠₃。对于用10％NaNO ₃加工的样品，已发现产生的微凹坑的表面质量最好，即0.062 µm 。通过使用具有相当大的精度和可重复性的这些电解质，在不锈钢（SS304）基板上成功地制造了具有最大深度为30μm，35μm和40μm的微凹坑的图案化阵列。实验证实了使用该技术获得具有最低咬边度的高纵横比微凹痕的可能性。此外，分析了摩擦测试结果以找出不同深度的微凹痕以及非凹痕样品的摩擦系数的变化。