Ingenieurwissenschaften und zugeordnete Tätigkeiten
Filtern
Erscheinungsjahr
- 2018 (142) (entfernen)
Dokumenttyp
- Vortrag (88)
- Posterpräsentation (44)
- Beitrag zu einem Tagungsband (5)
- Sonstiges (2)
- Zeitschriftenartikel (1)
- Dissertation (1)
- Forschungsbericht (1)
Referierte Publikation
- nein (142) (entfernen)
Schlagworte
- Corrosion (10)
- Mechanochemistry (10)
- SAXS (8)
- In situ (7)
- Thin polymeric films (7)
- Dielectric spectroscopy (6)
- Boehmite (5)
- MIC (5)
- Nanocomposites (5)
- Thermoresponsive polymer (5)
Organisationseinheit der BAM
- 6 Materialchemie (142) (entfernen)
Eingeladener Vortrag
- nein (88)
The processing of laser-induced periodic surface structures (LIPSS, ripples) on metals and semiconductors in ambient air is usually accompanied by superficial oxidation effects - widely neglected in the current literature. In this contribution, chemical, structural, and mechanical alterations in the formation of femtosecond LIPSS are characterized by a variety of surface analytical techniques, including energy dispersive X-ray analyses (EDX), X-ray photoelectron spectroscopy (XPS), micro Raman spectroscopy (µ-RS), and depth-profiling Auger electron microscopy (AEM). Alternative routes of electrochemical and thermal oxidation allow to qualify the relevance of superficial oxidation effects on the tribological performance in oil lubricated reciprocating sliding tribological tests (RSTT). It is revealed that the fs-laser processing of near-wavelength sized LIPSS on metals leads to the formation of a few hundreds of nanometer thick graded oxide layer, consisting mainly of amorphous oxides.
Regardless of its reduced hardness and limited thickness, this nanostructured surface layer can effciently prevent a direct metal-metal contact in the RSTT and may also act as an anchor layer for specific wear-reducing additives contained in the engine oil involved
The state of fresh concrete is predominantly determined by the rheological properties of the cement paste. In order to control performance spectra and requirements of novel concretes and to better understand macroscopic phenomena, comprehensive knowledge of the material behavior of fresh cement suspensions as well as of the complex relationships of mechanisms at the nano and micro scale are necessary. This work focuses on micro and nano rheology of suspensions of cementitious model systems and the influence of polycarboxylate-based admixtures on the rheology. The phenomena are driven by multiple parameters such as adsorption and particle interactions. Hence, the first part examines the interaction between polycarboxylate ether (PCE) and synthesized clinker phases and hydration products as model systems with regard to early hydration products.