Absorption behavior analysis of Carbon Fiber Reinforced Polymer in laser processing

laser machining of CFRP is a potential processing method as an alternative of conventional mechanical machining. This paper studies the absorption behavior of CFRP surface by establishing an optical absorption model based on the interaction of laser and fiber-matrix microstructure in material. In addition to polarization dependence, laser absorptivity is also subjected to the influence of wavelength, fiber volume fraction, and power intensity distribution within the laser spot. It is found that effect of multiple reflections in the microstructure would increase the absorptivity by 30%. Experiments have confirmed that absorption shows little fluctuation along the scanning line due to large laser spot. Short wavelength and arbitrarily polarized laser source are advantageous in achieving an effective and consistent machining process. CFRP sample for validation experiment is obtained through the nanosecond Nd:YVO4 laser milling process. The experiment data are in good agreement with the calculated results. (C) 2015 Optical Society of America