CeraMat

Porous ceramic materials are of considerable interest for a variety of chemical and industrial applications in extremely harsh conditions, particularly at very high temperatures for long time periods. A combined gel-casting-fugitive phase process employing agar as a natural gelling agent and polyethylene spheres as pore formers was exploited to produce porous ceramic bodies. Alumina and alumina–zirconia powders were used to prepare samples having a porosity of about 65–70–75 vol%. The composite powder was produced by a surface modification route, i.e.

In the last years, bioactive glasses and glass-ceramics drew the attention for their application in the production of implants. Among them, Bioglass® 45S5 is the most commonly used in terms of bioactivity, but its sintering behavior and the related glass-ceramics strongly depend on the followed synthesis process. For these reasons, this paper reports a comparison of the properties and the thermal behavior of bioactive 45S5 glasses produced by a conventional melting process starting from suitable solid precursors or an innovative sol-gel procedure.

Ceramic nanocomposites, containing at least one phase in the nanometric dimension, have received special interest in recent years. They have, in fact, demonstrated increased performance, reliability and lifetime with respect to monolithic ceramics.

In this work, the synthesis of RKKP bioactive glass composition by an aqueous sol-gel method is reported. A complete and systematic characterisation of the produced material was carried out. Characteristic functional groups were detected by Fourier transform infrared (FT-IR) spectroscopy, the thermal behaviour was investigated by simultaneous thermogravimetric and differential thermal analysis (TG-DTA), crystallisation kinetics and phase evolution were followed by X-ray diffraction (XRD) analyses.

Metal/ceramic composite materials were produced with core/shell structure by traditional pressing and the influence of the compacting parameters on the material properties has been studied. Different quantities of ceramic have been introduced to coat the base stainless steel powder. The use of a new generation of coated powders gives the opportunity to achieve near net shape massive composite exhibiting a composite microstructure, with a uniform dispersion of ceramic hard particles embedded in the metal matrix.

A method is proposed to quantitatively evaluate the preferred orientation of FeB and Fe2B crystals, constituting the borided layer obtained on iron. The preferred orientation is expressed by an empirically calculated factor σ, which allows a fair fit of calculated with observed peak intensities by X-ray diffraction analysis of the layer (R value ≤0.15). In a further investigation, this coefficient (σ) was used to quantitatively examine the influence of temperature and reagent composition on the degree of orientation of the phases obtained by boronizing pure iron.

The chemical and physical characteristics of ion-nitrided surface layers, obtained on α-β titanium alloys, are examined and correlated both with the working conditions adopted in the ion-nitriding process and with the alloy chemical composition. Besides the influence of the working parameters on the morphology and on the microstructures of the ion-nitrided surface layers, mainly the alloy element distributions both in surface coatings and in the substrate are analysed for five α-β titanium alloys of industrial use, and for titanium c,p.