On ablation characteristics based on two-temperature model involving a multivariate lattice heat capacity by ultrashort laser-irradiated in zirconia

To explore the mechanism of material removal, this paper conducts a systematic study on picosecond laser processing of zirconia by using both theory and experiment. Comparing the multivariate lattice heat capacity of the Einstein and Debye models, two-temperature model (TTM) is developed to improve the accuracy of the temperature field. Then, to verify the effectiveness of TTM proposed, ablation experiments are performed by single-pulse picosecond laser on zirconia at different laser energy density. The results show that the measured craters profiles are well agree with the simulated melting/vaporization temperature distribution. Micro-morphology is significantly affected by phase transition induced by temperature rise. Moreover, the results confirmed that increased temperature can lead to transition in zirconia crystal structure and oxygen vacancies. Finally, the effect of coupling temperature variations on the elemental and physical phase variations are focused to investigate, which can help to optimize the processing quality due to crystalline phase transitions. This study provides guidance for optimizing picosecond laser processing of zirconia.