CREEP OF PORCELAIN-CONTAINING SILICA AND ALUMINA

Hard porcelain ceramics find many applications because of their high hardness, high mechanical strength and moderate thermal-shock resistance. The addition of alumina as a filler to porcelain increases its strength at room temperature. In the present investigation, four-point-bend creep tests were carried out for porcelain-containing silica (SP-1 ) and alumina (AP-3) at 800, 900 and 1000-degrees-C. The creep data were analysed using a power-law creep, and the stress exponents were estimated. The activation energy for these two materials was found to be 45 kcal mol-1. The viscosity of the feldspar glassy phase was also determined from the creep tests. The test samples were analysed by scanning electron microscopy (SEM). The X-ray diffraction results (XRD) show that the amount of crystalline phase in the material increases after creep testing.