| Abstrakt: |
The aim of this work was to determine the effect of temperature and ZrO2addition on sintering and mechanical properties of porcelain prepared from local Algerian raw materials. Based on a preliminary work, the new selected composition was 25 wt.% feldspar, 25 wt.% quartz, and 50 wt.% kaolin (25 wt% kaolin Algerian nano-sized halloysite type + 25 wt% kaolin Tamazart) and containing different contents of ZrO2(5 and 8 wt%). It should be noticed here that all these used native raw materials are not against the environment. Samples were prepared by sintering the mixture at different temperatures (1000–1250 °C). Subsequently, the obtained phases in the elaborated samples were investigated by X-ray diffraction, Fourier transform infrared spectroscopy analyses, Raman spectroscopy, and SEM analysis. The optimum sintering conditions gave a relatively high density (2.47 g/cm3) and relatively excellent mechanical properties for these samples. The obtained porcelains were mainly constituted of quartz, mullite, and amorphous phases. The three-point flexural strength (3PFS), Vickers microhardness (VMH), and apparent porosity (PA) of porcelains sintered at 1200 °C were 132 MPa, 13.08 GPa, and 1.6%, respectively. The flexural strength value of this specimen is significantly higher than those reported for conventional porcelains (ranged between 60 and 80 MPa) even though for certain commercialized dental porcelains. |
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