Low-temperature fabrication of anorthite ceramics from kaolinite and calcium carbonate with boron oxide addition

Anorthite ceramics were fabricated by using groleg kaolinite, calcite and quartz with addition of boron oxide and without the need of very fine particles. Single phase anorthite ceramic with a density of 87% of the therotical was obtained at a sintering temperature of 950 °C. Moreover, no single anorthite phase could be obtained from boron free specimens even at a sintering temperature of 1100 °C. SEM investigation revealed that although boron free samples contain very small crystals together with some larger grains, boron containing samples generally had a fine grained matrix of crystals.