Thermal model based simulation of nanosecond pulsed laser irradiation of Ti6Al4V alloy

Abstract

A thermal model based simulation of nanosecond laser irradiation of a Ti6Al4V alloy has been described. Material ablation rates per laser pulse for a laser fluence of up to 15 J/cm2 experimentally measured by the author have shown good agreement with results of the model calculations, duly validating the theoretical approach. Calculated ablation threshold is also in agreement with the experimental data on Ti6Al4V. Calculated maximum temperature reached by a laser irradiated Ti6Al4V target has been compared with an estimated thermodynamic critical temperature for titanium, indicating that for laser fluence below 20 J/cm2 target ablation occurred largely through normal boiling and vaporization. Following this, a simulation based approach allows selection of optimum laser parameters successfully avoiding the onset of explosive boiling in the case of Ti6Al4V targets. Maintaining laser fluence close to the ablation threshold ensures surface texturing of Ti6Al4V with minimum associated surface damage.