To improve the hole-making quality for CFRP/Ti6Al4V stacks and optimize the helical milling process parameters

experiments were designed and implemented based on the Taguchi method. The spindle rotation speed

feed rate and pitch were taken as the design variables in the experiments. The hole diameter error

surface roughness and damage factor in the composite material layer were taken as the output indicators of the Taguchi model. Based on the Taguchi experimental results

the grey relational analysis and principal components analysis were adopted to optimize the helical milling process parameters. The influences of helical milling parameters on the signal noise ratios

principal components and the grey correlation degrees of output indicators were analyzed. The experiment results show that the optimal helical milling parameters are spindle speed 2000r/min

feed rate 0.02mm/r

and pitch 0.15mm.