An experimental study on fabricating microstructured surface by using LS-WEDM-prepared ball micro end mills

In recent years, there is an increasing demand for fabricating microstructures such as micro grooves, micro holes, micro dimples, and micro channels on various materials. Micro machining is an alternative method to manufacture microstructures due to its high efficiency and flexibility, and the micro end mill preparation is an essential step. In this study, the low-speed wire electrical discharge machining (LS-WEDM) is used to fabricate ball micro end mills with four cutting edges and radius of less than 200 μm, and the optimized parameters and multiple cutting strategies are adopted to improve machining surface quality and edge sharpness of ball micro end mills. Then, the micro dimples on soft and hard materials are formed by the designed and prepared ball micro end mills made of cemented carbide, respectively. The micro machining performance of ball micro end mills was evaluated by investigating the surface quality and microstructure of micro dimples, cutting force, and tool wear, and the influence of micro machining parameters on micro dimples is discussed in detail. Experimental results indicated that tool wear patterns mainly are adhesion friction and cutting edge damage, and the LS-WEDM-fabricated ball micro end mills with four cutting edges are potential to manufacture microstructures on hard and soft materials with acceptable surface quality and tool wear.