Effect of CaF2 and CaO Substituted for MgO on the Phase Evolution and Mechanical Properties of K-Fluorrichterite Glass Ceramics

• Published in: Journal of the American Ceramic Society Vol. 89; no. 2; pp. 587 - 595
• Main Authors: Mirsaneh, Mehdi, Reaney, Ian M., James, Peter F., Hatton, Paul V.
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Science Inc 01.02.2006; Blackwell; Wiley Subscription Services, Inc
• Subjects: Applied sciences; Biological and medical sciences; Biomedical materials; Building materials. Ceramics. Glasses; Ceramics; Chemical industry and chemicals; Exact sciences and technology; Glass-ceramics; Glasses; Mechanical properties; Medical sciences; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Scientific imaging; Silica; Technology. Biomaterials. Equipments. Material. Instrumentation; Additive; Calcium oxide; Transmission electron microscopy; Ion substitution; Biomaterial; Fluosilicates; Manufacturing; Experimental study; Glass ceramics; X ray diffraction; Calcium fluoride
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/j.1551-2916.2005.00713.x

Chain silicate glass ceramics based on K‐fluorrichterite (KNaCaMg5Si8O22F2, KFR) have potential for use in restorative dentistry and biomedical applications because they may be cast to shape and, when cerammed, have high biaxial flexural strength and fracture toughness. Excess CaO in canasite‐based chain silicate compositions is known to enhance their bioactivity. Therefore, two new glass ceramic compositions have been fabricated with 5 mol% CaF2 (Glass A) and 5 mol% CaO (Glass B) substituted for MgO in the KFR formula unit. The phase evolution of Glasses A and B was studied in detail using X‐ray diffraction and transmission electron microscopy. In addition, their mechanical properties were assessed. For Glass A, the fracture toughness (FT=2.66±0.02 MPa·m1/2) and biaxial flexural strength (BFS=227.3±24.5 MPa) were optimized for samples heat treated at 900°C for 4 h. In Glass B, however, the best FT (2.08±0.02 MPa·m1/2) and BFS (217.4±4.4 MPa) were obtained at 950°C. In view of their excellent mechanical properties and castability, Glasses A and B are considered potential candidates for fabrication of custom medical devices in restorative dentistry and moderate load‐bearing reconstructive bone surgery.