The Effect of TiN-, TiCN-, TiAlN-, and TiSiN Coated Tools on the Surface Defects and Geometric Tolerances of Holes in Multi-Spindle Drilling of Al2024 Alloy

The integrity of machined holes depends on many parameters, some which are related to the cutting tool (geometry, coating, material). Other influential parameters machining process variables (spindle speed, feed rate, workpiece material), all can affect quality hole and drilling induced damage its surface. This study investigates effect uncoated tools four types coatings (TiN-, TiCN-, TiAlN-, TiSiN) microstructure. analyzed several geometrical metrics, namely size, circularity, cylindricity, perpendicularity an Al2024 aluminum alloy using a multi-spindle that utilizes three drills capable creating multiple simultaneously. results showed carbide drill gave high-hole at low spindle speed. Regarding coated drills, TiCN produced with least deviation, cylindricity high speeds. TiSiN–carbide most oversized noticeable deformations their surface following TiAlN TiN. common found inner was smearing, marks, metal debris adhesion. ANOVA revealed type had highest percentage contribution mainly affected quality.