Experimental study on the influence of feed rate in micromilling of H13 tool steel

Abstract Micromachining is a small-scale machining process that enables the manufacturing of components with high dimensional and geometric precision. However, the micromilling of hard materials like H13 tool steel is challenging due to tool wear, surface integrity issues, and burr formation. This study experimentally evaluates the influence of feed rate on micromilling slots. The experiments employed (Al, Ti) N-coated end mills with a 400 µm diameter. Cutting parameters included a constant spindle speed of 32,000 rpm, an axial depth of 40 µm, and three distinct feed per tooth values: 1, 5, and 10 µm. Key performance indicators included tool wear, surface roughness (Ra), and burr characteristics. Results indicated that Ra values remained stable, fluctuating only between 0.118 µm and 0.144 µm, a behavior linked to the minimal tool wear observed. Regarding burr formation, wave-type, feather-type, and smaller burrs were identified, with larger formations occurring on the down-milling side. Notably, spheroidal chips formed during the micromilling of H13 tool steel.