Laser Cutting And The Influence On The Mechanical Properties Of Long Fibre Reinforced CF-PPS And CF-PEI
European Conference on Composite Materials (ECCM)
This paper investigates the mechanical properties of laser cut thermoplastic carbon fibre reinforced plastics (CFRP) compared to conventionally machined specimens, mainly mechanical cutting, using standard and non-standard test geometries. Polyphenylene sulfide (CF-PPS) and polyetherimide (CF-PEI) matrix materials were used for the experiments. The laminate utilized was a [04,904]T 5-harness satin weave layup. Different laser cutting strategies such as contour and multipass cutting were applied to assess the effect on the HAZ and the laser control parameters (speed, power, break times etc.) were optimised for these materials. The extent of the HAZ was measured by microscopy of cross-section specimens and was supported by Raman spectroscopy to validate the assumption of material modification in this region. The mechanical properties were measured by conducting quasi-static tests on unconditioned specimens and on specimens conditioned in oil, water, high humidity and after thermal cycling between -55°C and +85°C. The tests included in-plane shear tests combined with open-hole tension, interlaminar shear and bearing strength tests. The laser system has been developed to manufacture 3D brackets with mechanical tests performed on these components to assess the feasibility and performance of laser cutting for real industrial applications. The work is part of a Eurostars project (Co-Compact) with Element Materials Technology Hitchin Ltd, Laser on Demand GmbH and Laser Zentrum Hannover e.V.