Patent information in a large electrical company, exemplified by the situation at Siemens

The special situation of patent information is dealt with against the background of the general problems of information provision. The role of the Patent Department of Siemens as a user of patent information and in the distribution of patent information within the company is discussed. Finally, the present system of current patent information on granted patents and first publications is outlined and an outlook on future developments given.     

Molecular Dynamics Simulations of Amorphous Si–C–N Ceramics: Composition Dependence of the Atomic Structure

We have performed classical molecular dynamics simulations of amorphous Si–C–N materials. The dependence of the local order and of the microstructure on the chemical composition was investigated. Our simulations show that for a stoichiometric nitrogen/silicon ratio equal to or higher than 4/3, the amorphous ceramic separates into different amorphous domains, namely C-rich, SiN-rich, and SiC-rich phases. Below this ratio, the material is composed of mixed structures, homogeneously spread within the material. For a very particular composition range, we found that carbon atoms crystallize into monoatomic graphitic layers surrounding the SiN-rich domains.     

A mechanical spectroscopy study of the Zr69.5Cu12Ni11Al7.5 alloy

The vibrating reed technique has been used to investigate the Zr_69.5Cu₁₂Ni₁₁Al_7.5 glass forming alloy. The phase transformations of the material, as can be seen through the changes of the resonance frequency of the sample as a function of temperature, have been studied and the results have been compared with TEM and DSC measurements confirming the development, above T_g, of a metastable quasicrystalline state prior to crystallisation. Hydrogen-induced damping peaks were then observed in the different phases of the material with particular attention to the quasicrystalline state, where it seems that the microscopic reorientation mechanism responsible for the internal friction peaks should be similar to the one already known in the amorphous phase (hydrogen jumps between tetrahedral sites). Shortly after crystallisation, three damping peaks were observed, two of which are attributed to relaxation processes (Zener-type or intercrystalline Gorsky effect) taking place in the tetragonal CuZr₂ phase.     

Fabrication and characteristics of melt-spun Al ribbons reinforced with nano/micro-BN phases

Melt-spun aluminum ribbons with up to 5 wt.% of embedded nano/micro boron nitride (BN) phases, namely multiwalled BN nanotubes (BNNTs) or BN microparticles (BNMPs), were fabricated by melt-spinning in an argon atmosphere. The comparative structural characteristics were analyzed using X-ray diffraction, scanning and transmission electron microscopy, and internal friction measurements as a function of temperature within an 80–800 K range. Room temperature tensile tests were carried out on ribbons. These revealed reinforcing effects on pure Al-matrices after nano/micro-BN embedment for both added phases with the notably higher numbers peculiar to the BNNT-containing samples. The intrastructural interactions between BN additions and Al-matrices are discussed based on the structural analysis and the internal friction data.     

Local structure of metallic glasses as seen by mechanical hydrogen relaxation

As an application of hydrogen as a probe, the literature on the damping peak of hydrogen in about 30 amorphous alloys was examined with respect to the question of systematic structural differences between the different types of metallic glasses. A direct plot of measured peak temperatures, corrected to the same frequency, as a function of the peak height turned out to be most suitable for this purpose. Most of these data fall into a 40 K wide band, with no distinction between types like ‘metal–metalloid’, ‘metal–metal’, or ‘bulk’ glasses. This general result suggests, in particular, that the outstanding thermal stability of bulk metallic glasses does not come from a specific amorphous structure. Stronger deviations from the general behaviour, as observed very clearly for Pd-based glasses and tentatively also for phase-separating systems, still need a closer examination.