Effect of graphene on the trimming temperature and cutting tool life of composite materials****

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Composite materials are widely used in the aerospace industry. Their specific strength and stiffness, as well as their relative light weight compared to metallic alloys, convey them a net advantage for the production of lighter aircrafts. Even though composite components are produced to near net shape, additional machining operations are often required for assembly purposes. Unlike metallic materials, composite materials raise some specific problems during their high speed cutting in dry conditions. Typical defects, such as uncut fibers, loose fibers, cracks, as well as thermal degradation of the matrix, are commonly observed following cutting operations. These are mainly caused by heat and tool wear, which is severe due to the abrasive nature of the synthetic fibers involved. Tool life is consequently affected, and represents a significant share of the production cost, as the cutting tools, specially designed for composites, are very expensive. This project aims to develop an innovative approach to lower the cutting temperatures in order to improve the cutting tool life as well as the productivity through the use of more aggressive cutting speeds. The proposed approach adds graphene nanoparticles into the composite matrixes (epoxy and polyester) to improve machinability. These additives are known to have excellent thermal properties, which should provide an improved conductivity of the polymeric matrixes. This should result in better heat dissipation during the cutting process as compared to the case with plain matrixes, which present poor thermal conductivity. Furthermore, the graphene additive should act as a natural lubricant during the cutting process, which should also contribute to increasing tool life and the quality of cut surfaces. In the medium term, this project represents an opportunity for Canada to strengthen its leadership in the manufacture of high technology products through cost-effective cutting processes of composite materials.