Hydrodynamic effects on the surface morphology evolution of aluminum alloy under intense pulsed ion beam irradiation

As widely observed in many studies, the surface morphology of solids may change significantly after irradiation of intense pulsed ion beams (IPIB). This effect is crucial for surface treatments and may limit the utilization of IPIB as a novel method for surface processing in some cases. In present work, taking 6061 aluminum alloy for instance, the hydrodynamic behavior of the molten surface formed by IPIB irradiation was studied. By taking IPIB-induced heat transfer and level-set method flow field analysis with finite element method (FEM) it is revealed that under IPIB irradiation, the surface tension caused by the unevenness of curvature distribution of molten surface leads to mass transportation and a smoothening trend in the surface morphology evolution, meanwhile surface tension release is achieved. Irradiation of 6061 aluminum alloy was carried out and the trend in surface morphology evolution is consistent with the theoretical prediction.