Selective Ablation of thin Nickel-chromium-alloy Films Using Ultrashort Pulsed Laser

AbstractThe selective ablation of 100nm thin Nickel-Chromium-alloy films on glass substrate was investigated using femtosecond laser pulses (λ=1030nm, τp=170 fs, Ep,max=7μJ). The influence of the processing parameters such as fluence, pulse number and pulse repetition rate on the ablation process was examined. Single and multiple pulses ablation thresholds of the Nickel-Chromium-alloy film were determined and the incubation coefficient calculated. Optical and electron microscopy were employed to characterize the patterned area. As a result, different irradiation morphologies were observed, dependent from the processing parameters. A processing window for film side ablation of the Nickel-Chromium-alloy film without damaging the underlying glass substrate was found, however, the edge of the ablation craters were covered with laser induced periodic surface structures (LIPSS)

Anwendung des metallischen Mikro-3D-Druckes für die Demonstratorherstellung

Das am LHM etablierte Verfahren des Mikro-SLM ist eine Weiterentwicklung des bereits seit mehreren Jahren in der Industrie etablierten „makroskopischen“ Selektiven Laserschmelzen (SLM). Unter Verwendung von idealen Parametern wurden unter Zuhilfenahme der VDI3405 Bauteile, Teststrukturen unterschiedlicher Art und Struktur und ein Demonstrator aus den Edelstahlpulvern 316L und 17-4PH angefertigt. Die Besonderheiten des Verfahrens sind der geringe Fokusdurchmesser von <30 μm und die geringen Pulverkorngrößen von <10 μm. Dadurch können Bauteile mit extrem kleinen Strukturauflösungen realisiert werden

CURe MODERN - French-German infrastructure inspection, urban and regional planning

The Saarland-Lorraine-Western Palatinate region is distinguished by a centuries-old common history in which this region was not always separated by territorial borders. The Romans already left monuments of great historical and cultural relevance, which characterized the regional infrastructure up to the present day. In order to continue to preserve this significant cultural heritage as well as to maximize the life-cycle of modern engineering structures, the condition of these infrastructures should be continuously inspected and monitored. In the context of the INTERREG IV A Greater Region project "CURe MODERN - Initiative Modern Building Inspection, Urban and Regional Planning" funded by the European Union, a network of specialized partners from the regions of Saarland, Lorraine and Western Palatinate was set up, which will contribute to the cross-border exchange of experience in the field of non-destructive testing in civil engineering and urban and regional planning. This network facilitates cross-border provisions of non-destructive testing systems and new methods of urban and regional planning, which can be used in the framework of appropriate services for the condition assessment of infrastructures, the inspection of roads concerning their asphalt construction as well as the inspection of architectural monuments of reinforced and pre-stressed concrete. Framework for a complete inspection of such objects is a comprehensive data base, which is often either poorly or even not existent. This prevails in particular for the field of inspection of infrastructures difficult to access which are distinguished by their exceptional location, size or architecture. This contribution will show results from non-destructive inspection campaigns at engineering structures as well as cultural heritage which are merged with three dimensional georeferenced models of each structure and presented in a web based geoinformation system (GIS)