Hungarian Journal of Industrial Chemistry, Vol.24, No.1, 61-67, 1996
Preparation of Y-PSZ ceramics of controlled particle size distribution
Pressing of Y-PSZ powder was performed in a low pressure (4 bar) injection moulding equipment at 92 degrees C input material temperature and 2.5 - 7 Pas viscosity range. Model experiments were carried out to elaborate the deparaffination technology of the injection moulded specimens. The specific surface of the embedding matrix was the chosen variable during model experiments. In order to determine the effective diffusion coefficient in the deparaffinating compound, the twice semi-infinite one dimensional instationary model was used. Using the equation D-eff = f(x) We could also conclude that the deparaffination time can further be decreased by establishing a constant wall potential and thus an even more economical technology can be employed. After deparaffination the specimens were pre-sintered. Pre-sintered samples were heat treated in a two-stamped hot press at constant pressure and temperature for 10 - 70 minutes and specimens were investigated to determine their physical and morphological properties. Connections between changes in physical properties, the rate of changes and the duration of hot pressing were studied. It was found that hot-pressing process can be divided into three periods.