镁合金表面微结构阵列的电化学微加工

研究了镁合金的约束刻蚀微加工方法. 通过对电解过程中电极表面氢离子浓度变化以及刻蚀体系对镁合金的腐蚀速率的测量与分析, 对一些可能有刻蚀作用的刻蚀体系进行了研究. 选用亚硝酸钠作为产生刻蚀剂(硝酸)的前驱体、氢氧化钠作为捕捉剂、少量硅酸钠作为缓蚀剂的约束刻蚀体系, 使用具有规整三维微立方体点阵结构的模板, 在金属镁表面加工出具有与模板互补特性的点阵微结构, 复制加工的分辨率为亚微米级. 并对刻蚀过程机理进行了探讨与分析.

Electrochemical Micromachining Microstructure Lattice on Magnesium Alloy Surface

Micromachining of magnesium alloy by confined etchant layer technique (CELT) was investigated. The variation of hydrogen ion concentration on the electrode surface during the electrochemical process was explored for some thermodynamically available“etchant-scavenger”systems, and their corrosion rate to magnesium alloy was measured. An effective electrochemistry“etching-scavenging”system was selected. Using NaNO2 as precursor for electrochemically generating etchant HNO3, NaOH as scavenger, and small amount of Na2SiO3 as inhibitor, 3-D microstructure lattice on a mold was replicated onto the magnesium alloy surface. The microstructures processed were approximately the negative copy of the ones on the mold. Sub-micrometer scale resolution was reached. The result suggested that CELT could be applied to machine the 3-D microstructure on magnesium alloy surface, which had potential to be used for the fabrication of micro electromechanical systems (MEMS).