Activity: Talk or presentation › Oral presentation
Abstract: Steel moulds are widely used as forming tools during the fabrication of fibre reinforced thermoplastic composite parts. The aim of this work is to study sub-micron laser-induced surface modifications which help to control interfacial properties, such as undesirable sticking, between the composite polymer and the steel mould material. Stainless steel (AISI 430) samples were machined with a laser with wavelength of λ = 515 nm and 7 ps pulse duration. The periodicity of the Laser-induced Periodic Surface Structures (LIPSS) was determined, via fast Fourier transform of scanning electron microscope images, as a function of input parameters, such as effective number of laser pulses, pulse energy and accumulated fluence. Above a certain threshold, LIPSS appear over a broad range of fluences. Spatial frequencies were found to be between about λ/10 and ~λ for laser pulse energies of up to ~1 µJ. First results from experiments on interaction of composite polymers and steel moulds are also shown.