Laser Ablation of Aluminum

The laser ablation of metal carries relevance in a variety of engineering industries. This includes, but is not limited to, processes such as micromachining, or implementation on aircraft weaponry. The latter application is the reasoning for why aluminum is the specific metal in consideration, as it is commonly used for the construction of aircraft components. The scope of this project was to optimize the energy dispersed through laser ablation on aluminum by mathematical modeling. The transient conduction process in the aluminum was modeled using a 2-dimensional cylindrical coordinate system in both MATLAB and ANSYS/Fluent. These models were adopted to simulate various laser pulse patterns, to accomplish an initial objective of pulse optimization. Specifically, the various pulse patterns were compared, to obtain a pattern that allowed for the aluminum to reach its melting temperature at a specified depth, while consuming the least amount of power from the laser. The duration of, and the time between, the laser pulses were changed to investigate how these parameters affected the efficiency of the energy distribution. Since mass ejection decreases the efficiency of the laser pulse, Ansys/Fluent was used to model the gas dynamics of the ejected material as well. This decrease in efficiency occurs because the created plume absorbs some of the laser’s energy, thus reducing the energy being transferred to the target. Investigating this process, known as shielding, is the ultimate objective of the entire project. The optimal pulse pattern determined initially was remodeled, now considering energy absorption in the surrounding air region. Future studies will continue to investigate the process of shielding, to achieve full laser pulse optimization