Thermo-Physical Modelling and Simulation of Nanosecond Pulse Laser Ablation of Metal Considering the Combined Effect of Vaporization, Melt Flow and Phase Explosion
Sanasam Sunderlal Singh, Alika Khare and Shrikrishna N. Joshi
For efficient fabrication of microchannels and micro-features on metals, it is essential to accurately predict the performance measures such as the microchannel feature size and material removal during nanosecond laser-based micromachining of metals. The laser based thermal ablation of metal occurs mainly due to the vaporization, melt flow and phase explosion. However, scant literature is noted on considering these aspects together to develop a realistic numerical model. This paper presents the development of a non-linear thermo-physical model of nanosecond pulse laser ablation of stainless steel (SS316L) which mainly incorporates the effects of vaporization, melt flow and phase explosion. Moreover, the developed model considers the realistic assumptions such as Gaussian distribution of heat flux, surface reflectivity of the material based on the measured roughness of the work sample surface and the temperature dependent material properties. The computed results were found in good agreement with the experimental results.
Keywords: thermo-physical modelling, laser ablation, nanosecond, ablation depth, explosive boiling, normal vaporization, stainless steel SS 316L