2004

The aim of this work was to evaluate the hydro-erosion resistance of HVOF thermal sprayed coatings suitable to coat parts to be applied in the water treatment equipments and implants. Several coating materials such as Inconel 625, Inconel 625+10%vol. Al2O3, Stellite 6, AISI 316 stainless steel and WC-Co were applied on steel or cast iron substrates with different geometries. The derived specimens were tested in a special slurry abrasion/hydro-erosion test rig, that simulates the operating conditions of wet erosive wear.

New catalytic FeCrAlloy premixed fiber burners for natural gas combustion in domestic applications were developed according to an accurate microstructural design consisting of subsequent optimized steps: (i) optimal preoxidation of the FeCrAlloy fiber mat so as to develop the best possible Al2O3 layer for simultaneous prevention of deeper fiber oxidation at high temperature and optimal catalyst anchoring over the fiber surface, (ii) deposition via the either spray-pyrolysis or wash-coating technique of a previously developed perovskite catalyst (LaMnO3â 17MgO), and (iii) extensive testing of t

The investment casting process, extensively used for the production of jewels, is made up of different phases that, for their intrinsic typology, are deeply influenced by many chemical, physical as well as metallurgical factors. Even though investment casting has been used for decades, it is absolutely not properly optimised, also in consequence of the difficulty in deeply understanding, and therefore controlling, all the different phases of the process. It is therefore evident that different, and unfortunately many, kind of defects may appear in precious art-crafts.

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.

The mechanism of combustion synthesis of lanthanum chromite was investigated by carrying out simultaneous differential thermal analysis (DTA), thermal-gravimetric analysis (TGA) and quadrupole mass spectrometry measurements (MS). The whole process was found to involve several phenomena: urea and nitrates thermal decomposition, exothermal reactions occurring directly between nitrates and urea as well as between their decomposition products, final reaction between solid oxides.