Mechanical Properties of Barium-Mica-Containing Glass-Ceramics

• Published in: Nihon Seramikkusu Kyōkai gakujutsu ronbunshi Vol. 100; no. 1159; pp. 315 - 319
• Main Authors: Uno, T, Kasuga, T, Nakayama, S
• Format: Journal Article
• Language: English; Japanese
• Published: 01.03.1992
• ISSN: 0914-5400
• DOI: 10.2109/jcersj.100.315

Fine mica crystals (1-2 mu m) were precipitated by reheating glasses in the system Ba sub 0.5 Mg sub 3 (Si sub 3 AlO sub 10 )F sub 2 --Mg sub 2 Al sub 4 Si sub 5 O sub 18 --Ca sub 3 (PO sub 4 ) sub 2 . This glass-ceramics were two times stronger ( approx 350 MPa in bending) than conventional mica-containing glass-ceramics. The glass-ceramics contained two types of mica crystals, i.e. Ca-rich type and Ba-rich type. MgF sub 2 in the glass compositions was effective to increase the content of the Ba-mica crystal. It was found that Ba-rich mica crystal effectively deflected cracks to improve mechanical strength, and that Ca-rich mica crystal generated the ease of machining.