Abstrakt
A mixture of kaolin (92 wt.% of kaolinite) and laboratory-grade CaCO3 was used for anorthite preparation using the spark plasma sintering (SPS) technique. The powder was heated up to the maximum temperature (850 ?C?1100 ?C with a step of 50 ?C, heating rate 50 ?C/min) using the SPS device.
The as-prepared samples were compared with a reference sample produced by dry pressing and conventional firing. Rietveld refinement performed on the X-ray diffraction data revealed that before anorthite formation, gehlenite and Ca-feldspar appeared, which gradually transformed into anorthite with increasing temperature.
The sample prepared by SPS at 1100 ?C contained 90 wt.% of anorthite, while the anorthite content in the reference sample reached only 47 wt.%. The porosity of the samples prepared by SPS reached significantly lower values compared to that of the reference sample.
Therefore, SPS can be considered as a promising technique in the preparation of anorthite ceramics at lower temperatures.