Experimental study on helical milling of blind holes in Carbon Fiber Reinforced Polymer

Machining high-quality blind holes in Carbon Fiber Reinforced Polymer (CFRP) presents significant challenges due to its anisotropic structure, abrasive fibers, and susceptibility to defects such as delamination and fiber pullout. This study explores the application of helical milling technology for CFRP blind hole fabrication, which enhances machining quality by reducing cutting forces and improving surface integrity. Kinematic analysis and simulation of the helical toolpath are conducted using MATLAB to reveal the bottom surface formation process. Finite element analysis via ABAQUS is performed to evaluate the stress, strain, and cutting force behavior during milling. A three-factor, five-level Central Composite Design (CCD) based on Response Surface Methodology (RSM) is designed to optimize key parameters, including spindle speed, axial cutting depth per revolution, and feed rate. Quality indicators such as maximum inlet tear, bottom surface roughness, and hole diameter accuracy are evaluated. The results show that helical milling combined with RSM-based parameter optimization significantly improves blind hole machining quality and precision, providing theoretical and practical references for the manufacturing of CFRP precision components in aerospace and other fields.