Performance evaluation and optimization of drilling process with various PVD coated and lower end point angle drill bits on AZ31 Mg alloy

This study evaluates the drilling performance of PVD-coated drill bits on AZ31 magnesium alloy, focusing on optimizing surface roughness and geometric accuracy. Important variables including spindle speed, feed rate, and pecking depth were examined using Taguchi’s approach and ANOVA. DURANA-coated drill bits with a 55° endpoint angle achieved the best surface finish (0.701 µm), while PERTURA bits showed superior geometric precision. Results highlight the significant impact of coatings and process parameters on machining efficiency, providing insights for aerospace and biomedical applications. Future work will explore advanced coatings and AI-based optimization. This study focuses on the performance evaluation and optimization of drilling processes using Physical Vapor Deposition (PVD) coated drill bits on AZ31 magnesium alloy. Because of their excellent strength-to-weight ratio and low weight, magnesium alloys are finding growing use in biomedical, automotive, and aerospace applications. However, machining these alloys poses challenges, such as poor surface quality, tool wear, and thermal damage. The study looks at how critical parameters such as spindle speed, feed rate, and pecking depth affect surface roughness and geometric accuracy. Drill bits with various coatings, such as DURANA (Altima), PERTURA, and TIN, were evaluated alongside uncoated High-Speed Steel (HSS) bits. Taguchi’s design of experiments and ANOVA were employed to optimize these parameters, with surface roughness (Ra), diameter error, cylindricity, and roundness as performance metrics. The findings demonstrate that PVD-coated drill bits, particularly DURANA with a 55° endpoint angle, significantly enhance the surface quality and geometric accuracy in drilling AZ31 magnesium alloy. Optimized machining parameters improve efficiency and reduce tool wear, making these methods ideal for precision applications in aerospace, automotive, and biomedical industries. This study highlights the critical role of advanced coatings and parameter optimization in overcoming machining challenges for lightweight materials, paving the way for future innovations in manufacturing processes.