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

复合材料在航天工业中有着广泛的应用。它们的特殊强度和硬度，以及与金属合金相比相对较轻的重量，使它们在生产更轻的飞机方面具有净优势。即使复合材料部件被生产成接近净形状，为了装配的目的，通常也需要额外的加工操作。与金属材料不同，复合材料在干燥条件下的高速切削过程中会出现一些特殊的问题。典型的缺陷，如未切割的纤维、松散的纤维、裂纹以及基质的热降解，通常是在切割操作后观察到的。这些问题主要是由高温和工具磨损引起的，由于所涉及的合成纤维的磨损性质，这一点非常严重。刀具寿命因此受到影响，并占生产成本的很大一部分，因为专门为复合材料设计的刀具非常昂贵。该项目旨在开发一种创新的方法来降低切割温度，以便通过使用更激进的切割速度来提高刀具寿命和生产率。所提出的方法在复合材料(环氧树脂和聚酯)中添加石墨烯纳米颗粒来改善可加工性。众所周知，这些添加剂具有优异的热性能，这应该会改善聚合物基质的导电性。与导热性较差的平面矩阵相比，这应该会在切割过程中产生更好的散热效果。此外，石墨烯添加剂在切割过程中应起到天然润滑剂的作用，这也应有助于提高刀具寿命和切割表面质量。从中期来看，该项目是加拿大通过具有成本效益的复合材料切割工艺加强其在高科技产品制造方面的领导地位的机会。

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.