Preparation and properties of barium aluminosilicate glass-ceramics

Barium aluminosilicate (BAS) glass-ceramics were prepared by hot-pressing BAS glass powder derived via the sol-gel method, and the microstructure and properties were studied. Through control of composition, BAS glass-ceramics with two different types of microstructure were obtained. One is a sub-micrometre celsian surrounded by a thin layer of glassy phase, and the other is a celsian-mullite composite microstructure. BAS glass-ceramics with the celsian-mullite composite microstructure have a strength of 204 M Pa and a creep rate of less than or equal to 1.03x10(-4) h(-1) at 1250 degrees C. After heat treatment at 1250 degrees C for 100 h, no significant change of the microstructure was found, and the high-temperature strength did not decrease greatly. The BAS glass-ceramics prove to be a potentially good matrix for fibre- or whisker-reinforced composites for high-temperature applications.