Fabrication of Porous Anorthite Ceramic Insulation Using Solid Wastes.

Porous anorthite (CaAlSiO) ceramics, suitable for thermal insulation in buildings, were obtained using waste seashells as a source of CaO, kaolin as a source of AlO and SiO and banana peel as a pore former. Changing the volume of banana peel as well as the processing temperature was found to be an effective approach to control the thermo-mechanical properties of the obtained anorthite ceramics. The sintering of powder compacts containing up to 30 wt% banana peel at temperatures ranging from 1100 to 1200 °C resulted in anorthite ceramics possessing up to 45% open porosity, a compressive strength between 13 and 92 MPa, a bulk density between 1.

Heat Treatment of Geopolymer Samples Obtained by Varying Concentration of Sodium Hydroxide as Constituent of Alkali Activator.

In this paper, raw natural metakaolin (MK, Serbia) clay was used as a starting material for the synthesis of geopolymers for thermal treatment. Metakaolin was obtained by calcination of kaolin at 750 °C for 1 h while geopolymer samples were calcined at 900 °C, which is the key transition temperature. Metakaolin was activated by a solution of NaOH of various concentrations and sodium silicate.

The influence of yttrium-segregation-dependent phase partitioning and residual stresses on the aging and fracture behaviour of 3Y-TZP ceramics.

Unlabelled: The yttrium-segregation-dependent phase partitioning and residual stress development that influence both the aging and the fracture behaviour in 3Y-TZP bioceramics were studied by sintering alumina-free 3Y-TZP, varying the sintering temperature and the time, to yield ceramics with identical grain size distributions, but with different phase compositions. The structure and stability of the resulting tetragonal phases, in the form of transformable, yttria-lean t-ZrO (YLZ) and non-transformable, yttria-rich t″-ZrO and/or t'-ZrO (YRZ), were studied by X-ray diffraction (XRD) and focused ion beam scanning electron microscopy (FIB-SEM). The accelerated aging kinetics was fitted to the Mehl-Avrami-Johnson equation.