Laser Surface Processing of CFRP for Improved Adhesive Bonding
H. K. Sezer, S. Vijayakumar and S. Marimuthu
Carbon fibre reinforced polymer (CFRP) composites are increasingly being used in industries from aerospace and automotive to energy (renewable sector especially), medical, sports etc. Adhesive bonding is the preferred method of joining the composite materials, due to its advantages resulting in better in performance; however, the low surface energy of the polymer matrix of the CFRP results in poor adhesion characteristics, which needs to be addressed in order to achieve strong adhesive bonds. This paper investigates ultraviolet (UV) Nd:YAG laser surface treatment of CFRP to achieve surface conditions ideal for adhesive bonding. Contact angle measurement and single lap shear test were used to evaluate the performance of laser processed samples. The experimental results show that a better adhesive bonding performance can be achieved by producing a narrow deep channel over the CFRP surface using laser machining process. Samples processed with a laser fluence of 0.3 and 1.5 J/cm2 shows good adhesive bonding and fibre tear failure, compared to the samples processed at low laser fluence.
Keywords: Cleaning, CFRP, laser, resin, surface, UV, processing, manufacturing