Drilling characteristics of an E-glass fabric-reinforced polypropylene composite and an aluminum alloy: A comparative study

This paper presents an experimental study on the drilling characteristics of an E-glass fabric-reinforced polypropylene composite and aluminum alloy 6061-T6. Both materials have many similar structural applications, especially in the automotive industry. The drilling characteristics considered were axial thrust force, torque, temperature increase during drilling, and chip morphology. Both axial thrust force and torque were significantly higher for the aluminum alloy but were independent of the cutting speed for both materials. However, both increased linearly with increasing feed rate for the composite, but nonlinearly for the aluminum alloy. The Shaw-Oxford equation for predicting axial thrust and torque worked well with the aluminum alloy but did not fit the composite's axial thrust and torque characteristics. Both materials exhibited temperature rise at locations close to the drilled hole. The temperature rise decreased with increasing feed rate as well as increasing cutting speed; however the maximum temperature rise in the composite was significantly lower than that in the aluminum alloy. There was also a significant difference in the morphology of chips of these two materials.