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.

Optimization of forward pulsed currents for combining the precision shaping and polishing of nickel micro mould tools to reduce demoulding defects

“…Electropolishing is a non-contact electrochemical process that effectively removes burrs [ 19 ], asperities [ 20 ], and other impurities from metal surfaces [ 21 ]. Unlike other microfabrication techniques such as metal-assisted chemical etching [ 22 ], laser polishing [ 23 ], and deep reactive ion etching [ 24 ], electropolishing stands out because it removes material based on current density distribution [ 25 ], while other processes are limited by their anisotropic nature.…”

Experimental Evaluation of Surface Roughness, Burr Formation, and Tool Wear during Micro-Milling of Titanium Grade 9 (Ti-3Al-2.5V) Using Statistical Evaluation Methods

“…They optimize the process by varying machining parameters, and additionally describe a complementary electro polishing process to eliminate burrs and milling residuals. This work showcases the potential of micro-milling for fabricating precise micro-assemblies in MEMS, with a focus on improving surface quality and deburring [29]. In a related study, researchers aimed to improve tool wear measurement in micro-milling, especially in the presence of challenging burrs in Inconel 718.…”

Microfabrication of Sm2Co17 micromagnets for MEMS and micromotors using ultrashort pulsed hydro laser micromilling process

“…Not only small magnets are used, structures of magnets with micrometric features, specific geometries, or magnetic multipole pattern distributions [23] are also required in MEMS applications [24]. The combined use of permanent magnets, micrometric high-quality ferromagnetic parts [25] and microinductors [26][27] makes possible to achieve high specific power, torque and force in MEMS devices.…”