CeraMat

Interfacial reactions in Ti-6Al-4V/SiC Sigma fibres (coated with carbon and TiB2) were studied at different temperatures (600, 700 and 1000 °C). Interface microstructure was investigated by scanning electron microscopy and Auger electron spectroscopy. A simulation of the chemical phenomena occurring at the interfaces was carried out using powders of pure titanium, carbon and TiB2; the reaction products were identified by X-ray diffraction. The double coating of Sigma fibres is effective in delaying detrimental reactions with the matrix.

This review reports about the most used glass matrices (2) and reinforcements (3) for the preparation of glass- and glass-ceramic composites, their preparation methods (4), their properties (5) and the foreseen applications (6) in the field of transports, aerospace and biomedical. In particular, the thermal and mechanical properties of glass- and glass-ceramic matrix composites are compared with those of the most common metals and ceramics. Finally, some comments are reported about the probable development of the research in this field of great technological importance (7).

Titanium particle-reinforced glass ceramic matrix composites were prepared by sintering under an Ar atmosphere titanium particles (Tip) and the glass powders 45ZnO-15PbO-40B2O3 (mol%) (ZPB) for the ZPBT composites and 48.8SiO2-48.8CaO-2.4B2O3 (SCB) for the SCBT composites. Each composite was characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and differential thermal analysis. In order to modify the interfacial strength of the composites, glass matrices with different amounts of TiO2 (TZPB and TSCB, 7 and 2.1 mol% TiO2, respectively) were prepared.

Differential scanning calorimetry (DSC) is used in order to investigate the aging behaviour of AlCuMg alloys with different Cu:Mg ratios. Mechanism and kinetics of aging for these materials are compared with those of an (AlCuMg)-SiC composite. DSC results are in fairly good agreement with metastable AlCu and AlCuMg phase diagrams. The SiC reinforcement does not affect the precipitation path; furthermore, the activation energy for θ″ precipitation, calculated by Ozawa's method, is not appreciably different, taking into account the experimental error, for unreinforced alloy and composite.

This paper reports a study on the thermal stability of a Cu-K-V catalyst, which showed particular promise for low temperature combustion of diesel particulate. Prolonged treatments were performed at high temperatures (400-1000°C) for periods up to 15 days under different gaseous atmospheres.