Optimization of Milling Process Parameters of Carbon/Epoxy Composite Material for Minimizing Surface Roughness

Today, Carbon fiber-reinforced polymer composites (CFRP) have extensive use in different fields such as aerospace, automotive, oil, gas, and defense industries compared to metals, due to the high ratio of strength to weight. Machining of these materials regard to their non-homogeneity structure is complicated. Due to the different thermal expansion coefficients between the fibers and resin polymer composite milling materials difficult to create one of the final parts. Achieve optimal machining conditions, with high efficiency, which need proper analysis and careful investigation. Minimizing the machining time became important Due to developments in CNC technology. One of the time minimizing methods is high-speed machining technology. In this study, composite plates made of carbon/epoxy to a thickness of 10 millimeters, which are often used in the body of Aerospace structures and missiles, have been manufactured by hand layup. The cutting parameters used during the milling operation of the CFRP panel ranged from 1000 rpm to 7000 rpm for the spindle speed, feed rate from 1000 mm/min to 3000 mm/min, and lastly 1.0 mm to 3.0 mm range for depth of cut. the combination of spindle speed, feed rate, and depth of cut are studied at five different levels. 20 runs of experiments are performed based on Response Surface Methodology (RSM). the milling process with two-flute tungsten carbide - coated diamond insert with a 20 mm diameter was performed. their surface quality after milling process is measured. So after roughness, material removal rate and required analysis were performed. Spindle speed has a greatest effect on surface roughness. In conclusion, the influence of the cutting parameters is higher spindle speed, lower feed rate, and lower depth of cut resulting in low surface roughness. The optimized cutting parameters were spindle speed, feed rate, and depth of cut of 7000 rpm, 1000 mm/min and 1 mm respectively with the surface roughness of 1.9 um.