Experimental study on fabricating spirals microelectrode and micro-cutting tools by low speed wire electrical discharge turning

This study is focused on the fabrication of spirals microelectrode and spirals micro-cutting tools by using low speed wire electrical discharge turning (LS-WEDT). Firstly, the concept, movement relationship and machining principle of LS-WEDT process are analyzed, respectively. Then, the effects of new parameter of rotating speed on surface roughness, surface microstructure, elements change and material removal rate in LS-WEDT are evaluated in detail. Experimental results demonstrate that LS-WEDTed surface is significantly improved, micro-voids become more and smaller but foreign element contents increase with the increasing of rotating speed. More importantly, the space flexibility, negligible electrode wear and multiple cutting strategy of the LS-WEDT make it competent in fabricating micro tools with complex structure and high accuracy. Consequently, spirals microelectrode with high accuracy can be obtained for spiral pitch standard deviation of 2.57 and thread angle standard deviation of 0.96, and pitch length and thread numbers can be flexibly controlled in LS-WEDT. Additionally, the three spirals taper micro-cutting tool is fabricated by LS- WEDT based on the shape and cutting edge trajectory simulation results. Furthermore, the three spirals micro-cutting tool with average diameter of 175.77 μm and length of 1300 μm is firstly and successfully manufactured by LS-WEDT method.