Experimental Study on Orbital Drilling Force and Machining Quality of CFRP

Abstract

This paper aims to investigate orbital drilling process in carbon-fiber reinforced plastic (CFRP) composites with multi-point orbital drilling tool based on the robot automatic drilling system. One orthogonal experiment has been carried out, and the cutting forces of different parameters were measured online by dynamometer. Furthermore, the cutting force model was established through regression analysis, and the impacts of cutting parameters on thrust force were deeply analyzed. In addition, delamination and tear defects were inspected respectively, and the relationship between thrust force and delamination and tear was discussed. Our results indicate that thrust force increased with the increasing feed rate and axial feed depth, while decreased with the increasing spindle speed. Axial feed depth was found as the predominant factor on thrust force and defects. At last, the cutting parameters was optimized and then thrust force decreased more than 26% with almost none tear and burr around the hole, which indicates a better machine quality.