Investigation of the effects of machining parameters on drilling performance in drilling of aluminium composite panels

Abstract

The increasing use of aluminium composite panels (ACPs) in structural applications, particularly in the aerospace, automotive, and architectural sectors, demands high precision during drilling due to their layered structure and susceptibility to machining-induced damage. This study aims to systematically investigate the effects of spindle speed and feed rate on thrust force, burr formation, and tensile strength during the drilling of ACPs. The study not only identifies optimal drilling conditions to enhance machining quality but also reveals the critical relationships between cutting parameters, indirect effects of thrust force and burr formation, and the post-drilling tensile performance. Experimental results indicate that the high thrust force observed during the drilling of the upper aluminium layer originates from the material's stiffness. While a high thrust force was observed in the upper aluminium layer, a significant decrease occurred during the drilling of the polyethylene core. An increase in spindle speed combined with a decrease in feed rate resulted in a significant reduction in thrust force. Under conditions of low thrust force, the mechanical strength of the material was preserved, whereas high thrust forces adversely affected tensile performance. Additionally, an increased spindle speed at low feed rates led to higher burr formation, which positively contributed to tensile strength. However, excessive increases in feed rate caused deformation in burr height, negatively impacting tensile strength. Consequently, it was concluded that achieving optimal tensile strength requires maintaining a relatively high spindle speed alongside a low feed rate.