极间柔性多孔物充填型活动掩膜电解加工微坑技术

Active through-mask electrochemical machining with its interelectrode gap filled with flexible porous material

针对常规掩膜电解加工极难在非平面工件上高效制取表面织构的难题,在设计开发出进液、排液、导流等功能结构合为一体的特殊工具阴极的基础上,本文提出一种极间柔性多孔物充填型活动掩膜电解加工微坑技术,数值仿真并优化设计了极间流场,试验分析了掩膜厚度、极间电压、压紧力、脉冲参数等核心工艺参数对微坑几何特征及其分布特性的影响.基于优选工艺条件,分别在不锈钢平面与圆柱面上加工出几何特征尺寸分布较均匀的微坑阵列.极间柔性多孔物充填型活动掩膜电解加工对平面与曲面工件均能展现出较强的表面织构制备能力和适应性.

It has been one of issues that conventional through-mask electrochemical machining is very hard to fabricate surface texture efficiently on the non-planar workpiece. To solve this problem, a modified active through-mask electrochemical machining process （active TM-ECM） with its interelectrode gap filled with flexible porous material was proposed on the basis of development of a special tool cathode. The newly developed tool cathode allows for inlet and distributing of electrolyte as well as discharging of solution. The flow field within the interelectrode was analyzed and optimized numerically, and the effects of key process parameters including mask thickness, flexible porous layer thickness, clamping force and pulsed current parameter on the geometric profiles and their distributing characteristics of the machined microdimple were investigated experimentally. The arrays of microdimples with a fairly good distribution of geometric dimensions were successfully machined on both the stainless steel planar substrate and cylindrical workpiece by using the optimal process conditions. It is showed that the modified active TM-EMM process exhibits favorable machinability and applicability to produce microdimples on the planar and non-planar surfaces.