The Impact Of Cooling Strategies And Fixture Options On The Thermal Load During Laser Processing Of Carbon Fibre Reinforced Thermoplastics

This paper focusses on different fixture and cooling options and investigates their impact on the thermal load during laser processing of CFRP using a continuously emitting high-power solid state laser. Various combinations between fixtures, cooling options and process parameters were used. These options included cooling by pressurized air flow or water spraying when using uncooled fixtures with spacing under the CFRP plate. Another option included air flow or water spraying using water cooled fixtures with direct planar contact to the CFRP surface.

The surface temperatures were monitored by thermography during the cutting process, serving as an indicator for the effectiveness of the cooling options. The HAZ of selected cross-section specimens was measured, supporting the evaluation process of the cooling effectiveness.

The results revealed a distinct reduction in the surface temperatures when applying gas flow cooling compared to the absence of any cooling, while the effect of an additional water spray becomes apparent especially for an enhanced water flow. The highest heat dissipation was achieved by using a water cooled fixture. This effective cooling option enables the reduction of typically necessary delay times thus leading to higher process efficiency at a constantly low thermal load.

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