Experimental investigation of the effective parameters and performance of different types of structural tools in drilling CFRP/AL alloy stacks

In the modern aerospace industry, the application of hybrid multilayers (CFRP)/aluminum7075 stacks to manufacture various parts of modern aircraft fuselages is increasing in order to improve the quality of the structure. This study investigates the effective parameters when drilling carbon fiber composite (CFRP) and aluminum alloy 7075 stacks with different tool geometries/materials to compare dry machining with the cooling method and investigate the effect of cutting input variables of the drilling operation on machining results. With ANOVA analysis, the most influential parameter for the drilling operation of this kind of multilayer stack was determined as the feed rate. According to the experimental results, the surface roughness of the cooling system drilling was 38% lower than the average roughness of the other two tools (B and C). Moreover, the tool’s geometry and the cooling conditions (friction) have a greater influence on the drilling performance than the spindle speed and feed rate.