Experimental study of micromilling process and deburring electropolishing process on FeCo-based soft magnetic alloys

Abstract

FeCo-based soft magnetic alloys are commonly used in macroscale devices to improve its electromagnetic performance, whereas they have been barely used in the microscale. Current FeCo alloy micromanufacturing processes present some difficulties like low structural strength, oxidation at high temperature processes, stoichiometry mismatches in deposition processes and tough workability. In this work, a microcutting of FeCo-2 V-based soft magnetic alloys process is presented and described as an alternative method to obtain microparts with high magnetic properties and good geometrical finish. The results of the machining process are analysed by varying the machining parameters such as depth of cut, tool diameter, rotation speed and feed speed on simple machining operations. The study has been done for 50-μm-diameter endmill and 250-μm-diameter endmill tools. It concludes that the roughness is minimized when machining parameter combination is 0.24 mm/min of feed rate and 8 μm of depth of cut size for a 250-μm-diameter tool, while for a 50-μm-diameter tool, the selected feed rate is 0.24 mm/min, for a depth of cut between 2 and 4 μm. An automated precision 3-axis CNC station is used. Shapes needed for actuators such as angular slots, disks, or slender square geometries are shown in this work with excellent magnetic and mechanical properties. Additionally, a complementary electropolishing process is described. This process helps to eliminate burr in edges and residuals of the milling operation. This study demonstrates that micromilling can be a good alternative for microfabrication of FeCo-2 V components, suitable for precision microassemblies on MEMS.