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Production of Single Tracks of Ti-6Al-4V by Directed Energy Deposition to Determine the Layer Thickness for Multilayer Deposition
Published on: March 13, 2018
Accurate determination of the layer thickness of a multilayer polymer film by non-invasive multivariate confocal
Mingyi Zou1, Bastian Barton, Guru Geertz
1Fraunhofer Institute for Structural Durability and System Reliability LBF, Material Analytics, Schlossgartenstraße 6, D-64289 Darmstadt, Germany. bastian.barton@lbf.fraunhofer.de robert.bruell@lbf.fraunhofer.de.
Abstract:
Plastic films of multiple layers are widely used in packaging. While a detailed spatially resolving analysis is highly relevant, the currently used approaches are either tedious or lack spatial resolution. An advanced method of confocal Raman microscopy was therefore developed in this work, using a water immersion objective combined with multivariate data analysis and ray tracing models for analysing a commercial-grade five-layer plastic film. The water immersion objective and ray tracing models are able to reduce the refraction induced artefacts in depth profiling and ensure a correct and accurate interpretation of each layer thickness. The multivariate data analysis can distinguish each layer without prior knowledge of the sample and unique markers of each composition. Finally, the resulting thicknesses of the film layers could be successfully compared to complementary experimental results. In conclusion, each layer thickness of a multilayer polymer film and its chemical composition could be measured accurately and non-invasively without sample preparation.
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