Browsing by Author "Buser, Matthias"

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Open Access
Closed-loop laser volume ablation with adaptive scan paths
(2024) Buser, Matthias; Menold, Tobias; Michalowski, Andreas
This research focuses on closed-loop control in laser volume ablation, also known as laser milling. Such process control enables precise ablation results on workpieces with much wider tolerances regarding the initial surface geometry, internal structure, or its response to the incident laser beam, compared to conventional open-loop processing. However, state of the art closed-loop ablation systems incorporate the process control at the cost of increased processing time. The two main causes are the alternating between processing and measuring, and the use of static scan paths that do not adapt continuously to the evolving geometry of the workpiece during processing. This study addresses this issue by proposing a parallelized work flow of processing, measuring the surface topography and adaptive path planning, eliminating interruptions and achieving faster processing through continuously optimized scan paths. The realized machining system achieved a mean reduction in processing time of 29%, 36%, and 52% on three different test geometries compared to the state of the art.
Open Access
Enhanced scaling of material removal rate with high surface quality through combined laser processes
(2023) Buser, Matthias; Hofele, Markus; Menold, Tobias; Riegel, Harald; Michalowski, Andreas
AbstractIn the field of ultrashort pulse laser processing, the effective utilization of average power provided by todays laser systems presents an almost unsolvable challenge. This study aims to address this challenge in the context of laser volume ablation. We propose a solution for utilization of high average power while producing a high-quality finish, even when starting from arbitrary surfaces. The approach combines closed loop laser volume ablation, laser cleaning and laser polishing in a subsequent process strategy. The closed loop approach enables ablative laser processes to be used to produce precise target geometries and surfaces, even if the initial geometry of the component is very different from the target geometry. One application example is the post-processing of components manufactured using additive processes such as laser powder bed fusion. Therefore, we demonstrate automated removal of support structures and finishing of a sample made of AlSi10Mg material by laser powder bed fusion. The combination of laser ablation and laser polishing made it possible to significantly increase the productivity of the post-processing and achieving a surface roughness of Ra = 0.3 µm.
Open Access
A process-planning framework for sustainable manufacturing
(2021) Reiff, Colin; Buser, Matthias; Betten, Thomas; Onuseit, Volkher; Hoßfeld, Max; Wehner, Daniel; Riedel, Oliver
Process planning in manufacturing today focuses on optimizing the conflicting targets of cost, quality, and time. Due to increasing social awareness and subsequent governmental regulation, environmental impact becomes a fourth major aspect. Eventually, sustainability in manufacturing ensures future competitiveness. In this paper, a framework for the planning of sustainable manufacturing is proposed. It is based on the abstraction and generalization of manufacturing resources and part descriptions, which are matched and ranked using a multi-criteria decision analysis method. Manufacturing resources provide values for cost, quality, time and environmental impacts, which multiply with their usage within a manufacturing task for a specific part. The framework is validated with a detailed modeling of a laser machine as a resource revealing benefits and optimization potential of the underlying data model. Finally, the framework is applied to a use case of a flange part with two different manufacturing strategies, i.e., laser metal-wire deposition and conventional milling. The most influential parameters regarding the environmental impacts are the raw material input, the manufacturing energy consumption and the machine production itself. In general, the framework enabled the identification of non-predetermined manufacturing possibilities and the comprehensive comparison of production resources.