Evaluation of the Problems that Arise during CFRP Drilling

Abstract

In this paper are presented and analyzed a series of problems that are appearing during the CFRP machining. Due to their properties, the composite materials began to replace traditional materials (ferrous and non-ferrous) in a lot of industries leading out the development of new methods of machining or adaptation of the classic. Unlike traditional material, drilling in CFRP is more difficult due to inhomogeneity of the material, its high hardness but also due to lack of knowledge relating to how these materials behave. This paper investigates different types of tool wears as corner wear, welding, crater wear that are appearing in drilling operation due to the highly abrasive nature of the carbon fibers. Also, here is presented an evaluation that refers to the machined hole quality and describe defects as delamination, pull outs, fibers projections, pyrolysis and shape errors. The main goal of this paper is to verify the current status of technique in CFRP drilling in order to develop and produce a new drill geometry in a cooperation between the Technical University of Cluj-Napoca and the cutting tool company Gühring KG.