Title: Parametric optimization for aerospace quality holes using helical milling

Abstract

The optimized process parameters in helical milling of CFRP/Ti-6AL-4V stacks are evaluated to achieve H7 or better holes with minimum tool wear. Eccentricity, spindle speeds, helical pitch, tangential feed and nanoparticles lubricant are selected as input parameters while the machining performance is measured in terms of tool wear, holes accuracy and surface integrity (Surface Roughness, Burr Height). For better lubrication and environmental friendly machining, a MQL system is used. Results show that spindle speeds of 7500 rpm for CFRP, 1000 for Ti-6Al-4V, eccentricity of 2mm, 1mm pitch, tangential feed of 0.01 and 1% MoS2 resulted in more than 90% holes conforming to H6 standard with minimum tool wear.