Microstructure, internal stresses and fracture mechanics properties of quartzose silicate materials for whitewares

摘要

For the production of glassy-crystalline sintered materials, two ceramic bodies with different initial quartz contents are prepared, spray-dried, pressed uniaxially and dense-fired at temperatures of 1075 ℃ and 1265 ℃ in a pressureless sintering process. With increasing dense-sintering temperature, the phase composition in the materials changes. At an almost constant total crystallite content of around 60 %, above 1200℃ the content of quartz decreases while the content of cristobalite increases. This is connected with an increase in the 4-point bending strength from 190 to 250 MPa. This high strength of a whitewares silicate material is explained by changes to its internal stresses.