Effect of Alumina (Al2O3) to the Properties of Whiteware Porcelain

The effect of Al2O3 to the properties of whiteware porcelain such as water absorption, bulk density, flexural strength and crystalline phases were studied systematically. The result shows that the addition of alumina at maximum 5 wt.% in porcelain bodies increased the flexural strength of the fired bodies which can reach 55.5 MPa, 30% higher than 0.0% alumina content. However, slight decrease in the other physical and mechanical properties was observed with Al2O3 addition higher than 5 wt.%, which is believed to be due to increased corundum phase compared to mullite phase in porcelain body.

Estimating the reduction of the firing temperature produced by the addition of energetic fluxes in porcelain tiles through the Fluegel’s model

Reducing the firing temperature and accelerating the densification process bring economic and environmental benefits. This study used Fluegel’s viscosity model, developed for glasses, to estimate the decrease of the firing temperature produced by the introduction of energetic fluxes in a porcelain body. The experimental results confirmed the prediction of the model, a 30 ºC reduction in the temperature, for the addition of wollastonite. However, for the addition of spodumene, the reduction was slightly higher than the predicted. These results suggested that Fluegel’s model may be used to estimate the effects of the introduction of energetic fluxes in porcelain tile compositions. However, the predictions should be seen as a general orientation. Among the limitations of the model were the extrapolation of limit values established by the model for the composition and, above all, the initial hypothesis that the chemical composition of the vitreous phase in porcelain tiles is constant.

The Bending Strength of the Porcelain with the Substitution of Quartz by Palm Oil Fuel Ash

In this study the use of a treated palm oil fuel ash (POFA) as a substitute material in producing an improved porcelain ceramic has been presented. The POFA was grounded in a ball mill until the median particle size was reduced to about 50 μm. The POFA was heated at a temperature of 600 oC for 1.5 h in an electric furnace. It was used to substitute quartz in porcelain body from 0 wt% to 25 wt%. The mixed powder was pressed into pellets at pressure of 31 MPa, 61 MPa, 91 MPa and 121 MPa. All the pellets were sintered at a temperature of 1100 oC for 2 h soaking time. It was found out among other things that the bending strength of the samples increases with increase in substitution and also with the increase in mould presure. With a value of 45 MPa the bending strength of the samples containing 15 wt% sintered at a temperature of 1100 oC were higher than the standard porcelain. This could be attributed to compaction and sharp microstructural changes.

The application of LIBS and other techniques on Chinese low temperature glaze

ABSTRACT The focus of this paper is on analysis, comparison and research on the colorful low-temperature, lead-containing overglazes on glazed porcelain body and on the enamel glazes on the metal body of the Qing Dynasty by adopting several analytical methods. Analysis and tests on the element, boron in overglaze on glazed porcelain body and enamel glaze on metal body, were performed using laser induced breakdown spectroscopy (LIBS), and the results showed that Cloisonné enamel, painted enamel and Falangcai samples contained boron, while Famille Rose (Fencai) samples did not contain boron. Meanwhile, such analysis methods as laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), energy dispersive X-ray spectroscopy (EDXRF), Micro-Raman, stereomicroscope and Confocal laser scanning microscopy (CLSM) were used to test and observe the element composition, crystal composition and microstructure of the samples. The results illustrated that matrix glaze of Cloisonné enamel, painted enamel and Falangcai was the same. The yellow glaze was a lead-alkali glass and other color glazes were boron-lead-alkali glass, while all color glazes of Famille Rose were lead-alkali glass. Colorful low-temperature overglaze on glazed porcelain body and enamel glaze on metal body had a common practice and technology in the use of opacifiers and colorants. Compared to painted enamel, the painting technique of Famille Rose was more complicated, and effect was apparently praised as being superior.