RESEARCH ON LARGE DIAMETER HOLE DRILLING METHODOF THE CARBON FIBER REINFORCED PLASTICS

Abstract

Abstract: The Carbon Fiber Reinforced Plastics (CFRP) are often processed large-diameter holes in the aerospace industry. In the processing of large-diameter holes, the drilling without pilot hole will cause fiber tear, delamination in hole wall and other serious defects. This paper focuses on the processing principle and axial force of helical milling and prefabricated holes, and estimates the critical thrust force of drilling. In this paper, three methods of helical milling, pre-drilling with a pilot hole and without pilot hole drilling are used to establish the comparative experiment. And thrust force and quality of processing for these three methods are analyzed. The results show that the thrust force of drilling is mainly provided by the chisel edge of the twist drill bit, and thrust force is the main result of delamination. When the thrust force is less than the critical thrust force, the delamination is significantly reduced. The thrust force is reduced by 47% to 61% due to the elimination of the influence of chisel edge.The delamination factor at the exit level is 83% lower than drilling without pilot hole. Therefore, the method of pre-drilling with a pilot hole is outstanding when manufacturing large-diameter holes.

Key words: CFRP, helical milling, pilot hole, lamination

CLC Number:

TB332

WANG Gong-dong, LI Ying-chi, PENG Tian, LI Nan. RESEARCH ON LARGE DIAMETER HOLE DRILLING METHODOF THE CARBON FIBER REINFORCED PLASTICS[J]. Fiber Reinforced Plastics/Composites, 2018, 0(6): 48-53.

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