CeraMat

Forging behaviour of 2124 aluminium alloy containing 26 vol.% of SiC particles (average size 3 μm) was investigated by means of room and elevated temperature tensile tests (range of temperature 20–350°C). The results obtained were utilized to define the forging parameters (deformation ratio 3.5:1, strain rate 0.14 s−1, sample temperature during the hot deformation process ranging from 440 to 340°C). Microstructure of as-fabricated and forged specimens was investigated.

We studied the voltage and temperature dependency of the dynamic conductance of normal metal–MgB2 junctions obtained either with the point-contact technique (with Au and Pt tips) or by making Ag-paint spots on the surface of MgB2 samples. The fit of the conductance curves with the generalized BTK model gives evidence of pure s-wave gap symmetry. The temperature dependency of the gap, measured in Ag-paint junctions (dirty limit), follows the standard BCS curve with 2Δ/kBTc=3.3.

The oxidation behaviour of a multilayer SiC ceramic was investigated at high temperatures. The ceramic samples were processed by tape casting of a slurry containing α-SiC powders, forming of green tubular components and sintering without pressure. The oxidation resistance of this ceramic material was investigated by temperature programmed oxidation (TPO): the gaseous oxidation products were analysed by mass spectrometry. Thermal gravimetric analyses (TGA) were also performed.

Layered-type perovskite catalysts (A2−xA′xB1−yB′yO4±δ, where A, A′=La, K and B, B′=Cu, V), prepared by the citrates method and characterized by BET, XRD, and catalytic activity analysis, proved to be effective in the simultaneous removal of soot and NOx, the two prevalent pollutants in diesel exhaust gases, but only at temperatures as high as 450–500 °C, seldom reached at the exhaust line location unless next to the engine exit (close-coupled system).

Catalytic traps for diesel particulate removal are multifunctional reactors coupling filtration and catalytic combustion of soot. This paper reviews the most recent developments carried out at Politecnico di Torino concerning two different trap types: zirconia-toughened-alumina foams catalysed with Cs-V catalysts, operating according to a deep filtration mechanism, and cordierite or SiC wall-flow filters catalysed with perovskite catalysts (e.g. LaCr 0.9O3), enabling shallow-bed filtration.

The preparation of highly pure MgB2 powder is here presented. The two steps preparation method, together with an ad hoc projected reactor, permits us to obtain the desired stoichiometric phase without MgO impurities and other degradation compounds, which depress the superconductive properties. The formation of a liquid phase during the first step of the preparation leads to small grain size particles. New techniques of film preparation (Electrophoretic deposition) have also been approached.

Advances in gas turbine technology place an increasing demand on thermal protection systems of nickel-base superalloys in turbine blades. Current strategies for performance improvements are focused on thermal barrier coatings (TBC).

Nano-sized particles of ceria with high surface area were processed by solution combustion synthesis (SCS) and their catalytic activity towards combustion of carbonaceous materials was compared with that obtained by simple thermal decomposition of cerium nitrate, exhibiting the same specific surface area.