Fabrication of array of micro circular impressions using different electrolytes by maskless electrochemical micromachining

S Kunar,B Bhattacharyya,E Rajkeerthi,K Mandal

doi:10.1051/mfreview/2020012

Abstract

Maskless electrochemical micromachining (EMM) is a prominent technique for producing the array of micro circular impressions. A method for producing the array of micro circular impressions on stainless steel workpiece applying maskless electrochemical micromachining process is presented. The experimental setup consists of maskless EMM cell, electrode holding devices, electrical connections of electrodes and constricted vertical cross flow electrolyte system to carry out the experimental investigation. One non-conductive masked patterned tool can produce more than twenty six textured samples with high quality. A mathematical model is developed to estimate theoretically the radial overcut and machining depth of the generated array of micro circular impressions by this process and corroborate the experimental results. This study provides an elementary perceptive about maskless EMM process based on the effects of EMM process variables i.e. pulse frequency and duty ratio on surface characteristics including overcut and machining depth for NaCl, NaNO3 and NaNO3 + NaCl electrolytes. From the experimental investigation, it is observed that the combined effect of lower duty ratio and higher frequency generates the best array of micro circular impressions using the mixed electrolyte of NaNO3 + NaCl with mean radial overcut of 23.31 µm and mean machining depth of 14.1 µm.

Highlights

Maskless electrochemical micromachining (EMM) process is a prominent advanced micromachining technique for many advanced applications involving microsurface texturing containing array of micro circular impressions in the manufacturing of ultra-precision parts
A simple and unique texturing method of maskless EMM has been presented for the production of high quality array of micro circular impressions
The following conclusions have been summarized from experimental investigations: – Maskless EMM is an alternative technique for the generation of multiple high quality arrays of micro circular impressions economically

Summary

Introduction

Maskless EMM process is a prominent advanced micromachining technique for many advanced applications involving microsurface texturing containing array of micro circular impressions in the manufacturing of ultra-precision parts. The influence of inter electrode gap, applied voltage and flow rate is investigated on textured characteristics i.e. machining depth, overcut and surface roughness (Ra) using six types of masked patterned tools during maskless micro-electrochemical texturing process [16]. Maskless EMM is a significant alternative method due to its important benefits such as no heat affected zone, high machining rate, good surface finish, machinability of intricate shapes regardless of their hardness and toughness, reusability of a masked patterned tool, forceless machining, etc. It offers no mask removal process from machined workpiece, no chance of degradation of surface quality and higher productivity for the reusable single masked patterned tool, etc. An effort has been done to analysis the textured responses of generated dimple pattern for getting the best parametric setting

Experimental procedure

Development of mathematical model

Experimental results and discussion

Influence of process parameters on micro circular pattern

Analysis of micrographs

Conclusions