Model-based process planning for laser cutting operations under unsteady-state conditions

Boundary encroachment or cutting right up to pre-cut sections are examples of unsteady-state operations of the laser cutting process. Cornering and generating small diameter holes also fall into this category. Heat transfer is often frustrated here, resulting in bulk heating of the workpiece. This in turn leads to a degradation of the cut quality. Currently, trial-and-error based experimentation is needed in order to assure quality in these regions. Thus model-based process planning has the benefit of reducing this step whilst leading to an optimal solution. Numerical investigation of the laser-workpiece interaction zone quantifies significant effects of such transiency on cutting front mobility and beam coupling behavior. Non-linear power adaptation profiles are generated via the optimization strategy in order to stabilize cutting front temperatures. Experimental results demonstrate such process planning can produce quality improvements.