Modeling and Simulation of Multi-Pulse Femtosecond Laser Ablation of WC-6Co Cemented Carbide.

Abstract

In the process of femtosecond pulsed laser machining of cemented carbide, the simulation study of multi-pulse laser ablation is of great significance in revealing the laser ablation effect and guiding the machining process. When performing modeling, the consideration of the two-temperature equation, cumulative effect, and the improvement in the energy attenuation term in the laser heat source have a great influence on the simulation accuracy, but there are few related studies. This study aims to solve the above three problems and establish a more accurate finite element simulation model to reveal the effect of femtosecond laser ablation of cemented carbide. In order to apply the dual-temperature equation, the thermophysical parameters are chosen to approximate similar materials through experiments; in order to consider the cumulative effect, the accumulation coefficients are obtained through experiments and corrected based on the energy accumulation model for the laser heat source. In order to consider the influence of multi-pulse laser processing on the energy decay term in the traditional laser body heat source, the energy decay term is expanded by transforming the starting surface of the attenuation. The multi-pulse laser two-temperature model is established based on the WC-6Co material, the temperature field distribution and ablation morphology of the sample surface under the action of femtosecond laser are obtained, and the accuracy of the simulation model is verified by experimental results. On this basis, the influence of the average power and the number of pulses of the multi-pulse laser on the ablation effect of the material is quantitatively investigated.