Micro milling characteristics of LS-WEDM fabricated helical and corrugated micro end mill

Abstract

Micro milling offers a high potential for fabricating three-dimensional micro structure, such as micro grooves, micro channels and micro dimples. However, the fabrication of solid micro end mills with hard materials and complex structures poses many challenges. In this study, a new method based on low speed wire electrical discharge machining (LS-WEDM) is presented to prepare solid helical micro end mills. The machining process of helical micro end mill is kinematically modeled and simulated, which can realize visual predictability and provide theoretical basis for parameters selection. Experimental results indicated that corrugated micro end mill with about 269.8 μm in diameter and 1850.2 μm in length, and three helical blades micro end mill with 123.8 μm in diameter and 800 μm in length, six spirals and varied helical angle micro end mills can be flexibly prepared. Furthermore, the use of these micro end mills in hard material of DD5 single crystal nickel-based superalloy substrates is described to demonstrate their potential. Thus, the technique proposed in this study is significantly contribute to the fabrication of complex solid micro end mills with helical blades.