Influence of amorphous phase quantity on some characteristics of sintered ceramic tiles

This paper considers: relative density, porosity, pore diameters and compre ssive strength of sintered ceramic tiles as functions of the amorphous phas e quantity and the initial particle size. It suggests optimal quantities of amorphous phase, for the investigated systems. The investigations were performed on two fractions of spray dried ceramic p articles - small (63-90 mu m) and large (400-500 mu m). They were compacted and sintered in different atmospheres so that five small particle samples (with 1.6-8.1 Vol % of amorphous phase) and five large particle samples (wi th 3.5-12.2 Vol % of amorphous phase) were obtained. the quantities of amor phous phase were determined by employing IPAS (Image Processing Analyzing S ystem). All the samples were tested for relative density, porosity and comp ressive strength. Their average pore diameter as well as the most prevalent pore diameter was als determined. It was proven that small particle sample s have an optimum amount of the amorphous phase, in terms of density (62.1% ), porosity (47.5%) and average diameter of pores (45 mu m), within the int erval 5-7 Vol %. In the case of large particles, there is no optimum. Densi ty slightly decreases and porosity remained almost constant, regardless of the increase in amorphous phase in both kinds of samples. Maximum values we re achieved at the upper boundary of amorphous phase; that is, 24 MPa at 8. 1 vol % for the small particle samples and 29 MPa at 12.2 Vol % for the lar ge particle samples. It was concluded that the quantity of amorphous phase effects the characteristics of small particle samples much more than the ch aracteristics of large particle samples.