Optimization and characterization of tungsten thick coatings on copper based ally substrates

Tungsten is a promising armour material for plasma facing components of nuclear fusion reactors because of its low sputter rate and favourable thermo-mechanical properties. Among all the techniques able to realise W armours, plasma spray looks particularly attractive owing to its simplicity and low cost. The present work concerns the optimisation of spraying parameters aimed at 4–5 mm thickWcoating on copper–chromium–zirconium (Cu,Cr,Zr) alloy substrates. Characterisation of coatings was performed in order to assess microstructure, impurity content, density, tensile strength, adhesion strength, thermal conductivity and thermal expansion coefficient. The work performed has demonstrated the feasibility of thick W coatings on flat and curved geometries. These coatings appear as a reliable armour for medium heat flux plasma facing component

Structural and mechanical properties of welded joints of reduced activation martensitic steels

Gas tungsten arc welding and electron beam welding methods were used to realise welding pools on plates of reduced activation martensitic steels. Structural and mechanical features of these simulated joints have been investigated in as-welded and post-welding heat-treated conditions. The research allowed to assess how each welding technique affects the original mechanical properties of materials and to find suitable post-welding heat treatments. This paper reports results from experimental activities on BATMAN II and F82H mod. steels carried out in the frame of the European Blanket Project - Structural Materials Program. © 2002 Elsevier Science B.V. All rights reserved

Characterization of EUROFER 97 TIG-welded joints by FIMEC indentation tests

Welded joints of 25-mm thick plates of Eurofer-97,produced by a multi-pass GTAW+filler material method,have been investigated before and after different heat treatments to identify the temperature–time combination that gives mechanical properties as close as possible to those of the base material. After NDE (non-destructive examinations), samples were annealed in the temperature range 730–750 C for 1 and 2 h,microhardness was measured across the joints and FIMEC (flat-top cylinder indenter for mechanical characterization) tests were carried out in the molten zone (MZ),heat affected zone (HAZ) and in the matrix. The FIMEC method allowed determination on a local scale of the yield stress as obtained in standard tensile tests. Mechanical tests were supplemented by optical microscopy observations. The best results were obtained by the treatment at 750 C for 2 h: original characteristics are substantially recovered in the HAZ but not completely in the MZ

High temperature indentation tests on fusion reactor candidate materials

Flat-top cylinder indenter for mechanical characterization (FIMEC) is an indentation technique employing cylindrical punches with diameters ranging from 0.5 to 2 mm. The test gives pressure-penetration curves from which the yield stress can be determined. The FIMEC apparatus was developed to test materials in the temperature range from -180 to +200 degrees C. Recently, the heating system of FIMEC apparatus has been modified to operate up to 500 degrees C. So, in addition to providing yield stress over a more extended temperature range, it is possible to perform stress-relaxation tests at temperatures of great interest for several nuclear fusion reactor (NFR) alloys. Data on MANET-II, F82H mod., Eurofer-97, EM-10, AISI 316 L, Ti6Al4V and CuCrZr are presented and compared with those obtained by mechanical tests with standard methods. (c) 2007 Elsevier B.V. All rights reserved

TRICYCLIC HETEROAROMATIC SYSTEMS - [1]BENZOPYRANOPYRROL-4-ONES AND [1]BENZOPYRANO-1,2,3-TRIAZOL-4-ONES AS BENZODIAZEPINE RECEPTOR LIGANDS - SYNTHESIS AND STRUCTURE-ACTIVITY-RELATIONSHIPS

The synthesis, ability to displace [3H]flunitrazepam binding from bovine brain membranes, and GABA ratio of some [1]benzopyranopyrroles 1a-i and [1]benzopyrano-1,2,3-triazoles 2a,b are reported. The GABA ratios of some previously synthesized pyrazoloquinolines A and [1]benzopyranopyrazoles C are also presented in order to draw some structure-activity relationships among our benzodiazepine receptor ligands. 1,3-Diarylpyrrole derivatives 1a-h show similar affinity and efficacy to that of diazepam, while the 1-aryltriazoles 2a,b have no receptor affinity. Comparison of the latter results with those on previously reported compounds suggests that there are several hydrophobic regions on the benzodiazepine recognition site whose occupation gives rise to different affinity and efficacy

Preparation and characterization of SiC-graphite composite materials

Consiglio Nazionale delle Ricerche (CNR). Biblioteca Centrale / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Pyrazolo[4,5-c]quinolines. 2. Synthesis and specific inhibition of benzodiazepine receptor binding.

A series of 1-aryl-3,5-dimethyl-4,5-dihydro-1H-pyrazolo[4,5-c]quinolin-4-ones (2a-e) and 1-aryl-3-methyl-1H-pyrazolo[4,5-c]quinolines (3-7a-e) bearing different substituents at position 4 were prepared and tested for their ability to displace specific [3H]flunitrazepam binding from bovine brain membranes. The 5-N-methyl derivatives 2a-c,e were the compounds that bound with the highest affinity within this class. The replacement of the carbonyl group with other substituents and the resulting aromatization of the pyridine moiety greatly decreased the binding affinity. From a Lineweaver-Burk analysis on the most active compound 2b, it appears that the inhibition is a competitive one

TRICYCLIC HETEROAROMATIC SYSTEMS - SYNTHESIS, [H-3]FLUNITRAZEPAM BRAIN MEMBRANE-BINDING INHIBITION, AND STRUCTURE ACTIVITY RELATIONSHIPS OF 2,3-DIHYDRO-2-ARYL-4-R-[1]BENZOPYRANO[4,3-C]PYRAZOLE-3-ONES

We report the synthesis and binding activity to the central benzodiazepine receptors of some 2,3-dihydro-2-aryl-4-R-[1]benzopyrano[4,3-c]pyrazole-3-ones, which are isosteres of the CGS series. Although the compounds of the CGS series are potent ligands of the benzodiazepine receptors, none of the isosteres tested showed any significant inhibiting potency. This may be due to the change in electronic properties brought about by the replacement of the NH of the CGS series with an oxygen atom

Synthesis and binding studies of 1-arylpyrazolo[4,5-c]- and 2-arylpyrazolo[4,3-c]quinolin-4-ones.

The syntheses of some 2-aryl-3-methyl-4,5-dihydro-2H-pyrazolo [4,3-c] quinolin-4-ones and 1-aryl-3-methyl-4,5-dihydro-1H-pyrazolo-[4,5-c] quinolin-4-ones are reported. Some of the latter have shown a high activity in displacing specific [3H]-flunitrazepam binding from bovine brain membranes