Acoustic emission signal correlation with micro-machining characteristics of Ti-6Al-4 V alloy

Today’s technology is upgraded with miniaturization features in product development. Hence various industrial sectors are actively advancing their technological capabilities in the field of micro-machining processes to meet the growing demands in areas such as aerospace, oil, defence, biomedical science, and numerous other industries, all at the micro and nanoscales of manufacturing and design. The scientific contribution of this study lies in correlating drilling parameters with the number of holes drilled before failure, alongside monitoring tool conditions through acoustic emission signal analysis during high-speed micro-drilling. The experimentation was performed with L9 orthogonal array taguchi design using three variable parameters namely spindle speed (N = 25,000 rpm, 35,000 rpm, 45,000 rpm), feed rate (f = 1.03 mm/min, 1.45 mm/min, 1.87 mm/min) and drill size (d = 200 μm, 300 μm, 400 μm). For the high speed micro-drilling process TiN coated tungsten carbide microdrills are used. It is observed that number of holes drilled before failure decreases as the feed rate and drill size increases, also the low spindle speeds with low feed rates and high spindle speeds with high feed rates does not have a significant effect on tool life. This study enhances understanding by providing insights into the relationships between machining parameters, tool wear, and process stability, particularly valuable in micro-machining applications where precision and tool longevity are critical factors.