Fig. 1. Crystal structure diagram of α-Al₂O₃

Fig. 2. Schematic of tetragonal cell reconstruction. (a) Schematic of quadrilateral cell reconstruction; (b) tetragonal crystal cell

Fig. 3. Schematic of Al₂O₃ ceramic crystal model

Fig. 4. Schematic of instantaneous energy of Al₂O₃ ceramic particles irradiated by femtosecond laser with different shapes of focal spots for 1 fs. (a) Rectangular focal spot; (b) circular focal spot; (c) elliptical focal spot

Fig. 5. Molecular dynamics model of interaction between femtosecond laser and Al₂O₃ ceramics

Fig. 6. Schematic of instantaneous total energy evolution of Al₂O₃ ceramic particles under femtosecond laser irradiation with different energy densities. (a) 3.7 J/cm²; (b) 4.7 J/cm²; (c) 5.7 J/cm² ; (d) 6.7 J/cm²

Fig. 7. Spatiotemporal evolution of lattice temperature in Al₂O₃ ceramics irradiated with femtosecond lasers of different energy densities. (a) 5.7 J/cm²; (b) 6.7 J/cm²

Fig. 8. Spatiotemporal evolution of internal pressure in Al₂O₃ ceramics irradiated with femtosecond lasers of different energy densities. (a) 5.7 J/cm²; (b) 6.7 J/cm²

Fig. 9. Schematic of instantaneous total energy evolution of Al₂O₃ ceramic particles under femtosecond laser irradiation with different energy densities. (a) 7.7 J/cm²; (b) 8.7 J/cm²

Fig. 10. Spatiotemporal evolution of atomic number in Al₂O₃ ceramic grid irradiated by femtosecond laser with the same energy density. (a) 5.7 J/cm²; (b) 6.7 J/cm²; (c) 7.7 J/cm²; (d) 8.7 J/cm²

Fig. 11. Spatiotemporal evolution of temperature in Al₂O₃ ceramics irradiated with femtosecond lasers of different energy densities. (a) 5.7 J/cm²; (b) 6.7 J/cm²; (c) 7.7 J/cm²; (d) 8.7 J/cm²

Fig. 12. Spatiotemporal evolution of pressure in Al₂O₃ ceramics under femtosecond laser irradiation with different energy densities. (a) 5.7 J/cm²; (b) 6.7 J/cm²; (c) 7.7 J/cm² ; (d) 8.7 J/cm²

Fig. 13. Schematic of instantaneous total energy evolution of Al₂O₃ ceramic particles irradiated with femtosecond laser of different pulse widths. (a) 100 fs; (b) 200 fs; (c) 500 fs ; (d) 1000 fs

Fig. 14. Spatiotemporal evolution of atomic number in Al₂O₃ ceramic grid irradiated with femtosecond laser of different pulse widths. (a) 100 fs; (b) 200 fs; (c) 500 fs; (d) 1000 fs

Fig. 15. Spatiotemporal evolution of temperature in Al₂O₃ ceramics irradiated with femtosecond lasers of different pulse widths. (a) 100 fs; (b) 200 fs; (c) 500 fs; (d) 1000 fs

Fig. 16. Spatiotemporal evolution of pressure on Al₂O₃ ceramics under femtosecond laser irradiation with different pulse widths. (a) 100 fs; (b) 200 fs; (c) 500 fs; (d) 1000 fs