Foundational Study On The Objective Design Of The Porcelain Sintered At Low Temperature

It is an inevitable trend to realize informational and numerical management for the enterprise modernization, although this is an enormous challenge to traditional porcelain enterprise. In this course, the key work should be the realization of quantitative control over porcelain product performance, of which the core is to realize the target design of porcelain formula. However the foundation for the realization of the above–mentioned task is to determine all influences upon product performance and process performance due to all kinds of process factors.The research in this article has made a relatively systematical analysis to sintering performance, clay material plasticity as well as body whiteness degrees with the application of some research means in modern times such as X-ray diffraction, differential thermal analysis and with some methods such as non-linear regression analysis, thermo- dynamic analysis, etc. methods.Non-linear regression method has been taken into application to analyze the effects upon sintering performances from all chemical compounding components. Taken the interactions among aggregate components and fluxing agent components into consideration, the interactive variables S/A and R2O/RO have been brought into regression model, in the same time the quadratic curve regression model has been designed, so the obtained regression equation has reasonably reflected the effects upon sintering temperature from all chemicals and determined the quantitative relations between all chemical components and sintering temperatures. The regression equation shows that if SiO2/Al2O3 can be properly raised in the range of daily porcelain compositions, and R2O/RO can be controlled nearby 2.80, the lowest sintering temperature can be obtained to the same quantity of flux. This provides a practical way to reasonably determine the relations among low-temperature sintering temperatures, plasticity and thermal expansion-coefficients for daily porcelains. Premised that the chemical components are the same, the mineral composition changes will have some influences upon porcelain body sintering temperatures to a certain extent. However because of little change of composition ratio among all kinds of clays in practical production, the influences from mineral components can be ignored. The experiments with regression equation showed that all sintering temperatures of bodies have reached the designed standards.The plasticity of all kinds of clays composed of different mineral components have been measured. The measurement methods, which make the clay-water film system be similar to practical clay state, as well as plasticity index 2, have also been determined so as to ensure the additive ability of clay plasticity indexes.Having studied the physical and chemical changing processes in the course of low- temperature sintering process and the body coloring mechanism, we found the physical and chemical changing processes are basically the same as high-temperature sintered body, but only because of the appearance of low-temperature liquid phase and the existence of residual carbon, a closed space of low-oxygen pressure decrement will be formed, and so the liable huge-colored material Fe3O4 will be consequently formed. In the course of low-temperature sintering process, besides as everyone knows that the element Fe and element Ti contents will considerably lower whiteness degrees, the carbon content in materials as well as whether the material is liable to sintering loss will have also considerably influences upon body whiteness degrees.