Laser ablation behavior of a 2-D C/SiC-Ti3SiC2 composite

Abstract

When subjected to laser irradiation of different power densities, Ti3SiC2 MAX phase-modified 2-D C/SiC composite experiences various chemical and physical reactions and demonstrates various ablation resistance. An in-situ observation measurement is developed to obtain the instantaneous mesoscopic ablation process for revealing the ablation mechanism. Then scanning electron microscope (SEM) and X-ray energy dispersive spectroscopy (EDS) tests are performed to determine the reaction process. The results show that the Ti3SiC2 MAX phase can effectively prevent laser irradiation into the material at a laser power density below 636.5 W/cm2. The advantage of ablation resistance disappears at a high laser power density of 2546 W/cm2 due to the decomposition and sublimation of SiC and Ti3SiC2. A chart of ablation mechanisms versus laser power density is constructed based on the instantaneous mesoscopic ablation behavior, macro/meso/microscopic ablation morphology, and temperature history. It is also found that there are two forms of "Temperature Jump" phenomena. One is the accelerated temperature rise in the temperature history of the single-irradiation event. The other is the step point in the maximum temperature curve for multiple irradiation events. The mechanisms of the "Temperature Jump" phenomena are explained based on the interface energy balance.