Investigations on the thermal effect caused by laser cutting with respect to static strength of CFRP
International Journal of Machine Tools & Manufacture
Type: Zeitschriftenaufsatz (reviewed)
To increase production volume and efficiency in the area of CFRP (carbon fiber-reinforced plastics) component production, fast, flexible and cost-efficient technologies are needed. One process that is necessary during CFRP component production is trimming and cutting. Although laser cutting in principle meets these requirements, it is often not used for component trimming and contour cutting, due to insufficient knowledge about the influences of thermal machining on the material behavior. It is a common argument that lasers, as a thermally acting tool, may damage the CFRP, thus reducing its strength properties. This, however, has never been proven or disproven. Therefore, this paper presents investigations on the influence of laser cutting on the static strength of a CFRP laminate. The material is cut using three different high-power laser sources: a pulsed Nd:YAG laser, a disk laser and a CO2 laser. Appropriate cutting parameters have been found, and the results in cut quality and heat-affected zone are discussed. With these parameter sets, specimens for tensile strength and bending tests have been prepared. These specimens have been tested under static tensile and bending conditions, and the results have been compared to conventional milling as well as abrasive water-jet cut samples. Though a clear dependency of the static strength values on the heat-affected zone was detected, all strengths were found to be far above the material values given by the producer of the laminate.