Comparison of Deep Drilling Efficiency between Ultrasonic Vibration-Assisted Drilling and Conventional Drilling based on Specific Energy Consumption

Abstract

Deep hole drilling remains a persistent challenge in both research and industry due to high friction and inadequate chip evacuation, which leads to inefficiencies. This study evaluates the efficiency of deep drilling using ultrasonic vibration-assisted drilling (UAD) by comparing it with conventional drilling (CD), with specific energy consumption (SEC) as the primary metric derived from torque measurements. Here, SEC is defined as an accumulated function integrating energy consumption over the entire drilling process, mitigating non-linear and stochastic variations common in deep drilling. Experiments were conducted on Al-6061 aluminum alloy under continuous dry drilling conditions, with variations in spindle speed, feed rate, and hole diameter. The results demonstrate that UAD significantly improves drilling efficiency compared to CD. Specifically, the SEC value for UAD was approximately 21.44% to 77.74% lower than that for CD across all experimental conditions. Moreover, with optimized parameters, UAD achieved a 25% increase in material removal rate (MRR) and a 33.4% reduction in SEC compared to CD. These findings highlight UAD’s potential to enhance deep hole drilling efficiency, offering promising applications for industrial machining processes.