Multiphysics modeling femtosecond laser ablation of Ti6Al4V with material transient properties.

Femtosecond laser ablation associates with a series of multiphysics phenomena (electron thermalization, electron thermal conduction, electron-phonon coupled energy transport, melting, vaporization and phase explosion) and the instant variation of material transient properties, which impacts the laser energy absorption and the subsequent material removal. In this work, a multiphysics model with material transient properties is developed to study the femtosecond laser ablation of Ti6Al4V. A two-dimensional axisymmetric simulation is performed. The predicted ablation depth and ablation diameter with material transient properties show good agreements with the experimental data. The necessity of material transient properties for femtosecond laser ablation is demonstrated. Besides analyzing the roles of material transient properties on femtosecond laser ablation, the ablation thresholds of Ti6Al4V are probed for different pulse durations. In addition, the impact of pulse duration on femtosecond laser heat affected zone is studied. This work contributes to understand roles of material transient properties in femtosecond laser ablation. • A multiphysics model of femtosecond laser ablation is developed. • Material transient properties in femtosecond laser ablation are included. • Impacts of material transient properties are quantitatively studied. • Optical penetration depth is found as the dominant transient material property. • Heat affected zones at different laser pulse durations are compared. [ABSTRACT FROM AUTHOR]