The structure and the formation mechanism of brittle eutectic phases and hot cracks formed at grain boundaries were investigated in two Ni-Mo-Cr superalloys with different silicon contents (0.06 and 0.46 wt.%). The eutectic phases and hot cracks can be observed along the rolling direction in the 0.46 wt.% Si heat when heated to 1335 °C or a higher ...
The in-situ crystallization of anatase and rutile on chemically-treated Ti-foils in the temperature range 20-900 degrees C has been investigated using synchrotron radiation diffraction and x-ray diffraction. The processing methodology has a profound influence on the morphology, crystallite size and growth rate of nanostructured TiO2. The anatase fo...
The considered materials in this work are (Ba,Sr)TiO_3, SrTiO_3 and SrTa_2O_6 and the oxides from the group IVb metals: Ti, Zr and Hf. The films were deposited on Platinum and Silicon substrates in order to evaluate the dielectric properties for applications in metal-insulator-metal (MIM) structures as well as in metal-insulator-semiconductor (MIS)...
Germany
Germany
The challenge for silicon particle detectors in future high energy physics experiments caused by extreme radiation fields can only be met by an appropriate defect engineering of the starting material. Appreciable improvements had already been obtained by enriching high resistivity float zone silicon with oxygen as demonstrated by the CERN RD48 coll...
Germany
Germany
Oxidation-resistant materials were to be identified, and fundamental investigations were to be carried out on the oxidation mechanism and chipping behaviour. The following results were obtained: 1. The new COST cast alloys CB5-CB9 with 11-12 percent Cr have very low oxidation rates. The corresponding forged alloys FB5-FB9 are similar with regard to...
This thesis deals with quantitative studies of equilibrium and non-equilibrium phenomena on Pt(111) and Cu(100) surfaces using scanning tunneling microscopy (STM). The aim of this work is apply theoretical methods based on statistical physics to determine atomistic energy parameters of surface diffusion processes on metal substrates which cannot be...
