5 Werkstofftechnik
Filtern
Dokumenttyp
- Vortrag (2)
- Zeitschriftenartikel (1)
- Posterpräsentation (1)
Schlagworte
- Additive Fertigung (1)
- Additive manufacturing (1)
- Cement-based materials (1)
- LIBS (1)
- NDT (1)
- Particle size (1)
- Plasma imaging (1)
- Polymerwissenschaften (1)
- ProMoAM (1)
- Process monitoring (1)
- Prozessmonitoring (1)
- Shadowgraphy (1)
Organisationseinheit der BAM
- 1.9 Chemische und optische Sensorik (4) (entfernen)
Eingeladener Vortrag
- nein (2)
Die Bundesanstalt für Materialforschung und -prüfung (BAM) ist eine Ressortforschungseinrichtung, die zum Schutz von Mensch, Umwelt und Sachgüter, forscht, prüft und berät. Im Fokus aller Tätigkeiten in der Materialwissenschaft, der Werkstofftechnik und der Chemie steht dabei die technische Sicherheit von Produkten und Prozessen. Dazu werden Substanzen, Werkstoffe, Bauteile, Komponenten und Anlagen sowie natürliche und technische Systeme erforscht und auf sicheren Umgang oder Betrieb geprüft und bewertet. Schwerpunkt des Vortrages sind multimodale Polymeranalytik, nanoskalige Sensormaterialien und die Charakterisierung von technischen Eigenschaften von Polymeren sowie ihre Alterung und Umweltrelevanz.
The project ProMoAM is presented. The goal of the project is to evaluate which NDT techniques or combination of techniques is suited for in-situ quality assurance in additive manufacturing of metals. To this end, also 3d-data fusion and visualization techniques are applied. Additional ex-situ NDT-techniques are used as references for defect detection and quantification. Feasability studies for NDT-techniques that are presently not applicable for in-situ use are performed as well.
The presentation gives a brief overview of the whole project and the different involved NDT-techniques.
The effect of particle grain sizes in different cement-based mixtures on the laser-induced plasma evolution is studied using two experimental methods: (i) temporal and spatial evolution of the laser-induced shock wave is investigated using shadowgraphy and two-dimensional plasma imaging, and (ii) temporal and spatial distribution of elements in the plasma is investigated using two-dimensional spectral imaging. This study is motivated by the interest in applying laser-induced breakdown spectroscopy (LIBS) for chemical analysis of concrete, and subsequently obtain information related to damage assessment of structures like bridges and parking decks. The distribution of grain sizes is of major interest in civil engineering as for making concrete different aggregate grain sizes defined by a sieving curve (64mm to 0.125 mm) are needed. Aggregates up to a size of 180 μm can be excluded from the data set, therefore only the amount of small aggregates with a grain size below 180 μm must be considered with LIBS. All components of the concrete with a grain size smaller than 0.125mm are related to the flour grain content. Tested samples consisted of dry and hardened cement paste (water-cement ratio w/z=0.5), which served as a reference. Aggregate mixtures were made by adding flour grains (size 40 μm) and silica fume (size 0.1 μm) in different ratios to cement: 10%, 30%, 50% and 60%, all combined to the remaining percentage of dry or hydrated cement. The visualization results show that a dependance in the evolution of the plasma as a function of sample grain size can be detected only in the initial stages of the plasma formation, that is, at the initial 3 μs of the plasma life. Spectral information reveals the elemental distribution of the silicon and calcium in plasma, in both neutral and ionized form. Here also, a significant effect is observed in the first 1 μs of the plasma lifetime.