Improved performances of lithium disilicate glass-ceramics by seeds induced crystallization

Abstract

Self-reinforced lithium disilicate (Li 2 Si 2 O 5 ) glass-ceramics were hot pressing sintered by introducing 5 wt% Li 2 Si 2 O 5 crystal seeds into two different glass systems. The results show that the seeds play an important role in the crystallization inducement, microstructural and properties improvement of the glass, especially for the glass powder without the nucleating agent of P 2 O 5 . The microstructure features a wider bimodal grain size distribution with large rod-like crystals epitaxially grown along the seeds and small crystals nucleated from the glass powder itself, contributes to the improvement of the performance especially the fracture toughness. The 4C5S specimen exhibited the best comprehensive properties with a good flexural strength (396 ± 7 MPa), improved fracture toughness (3.31 ± 0.19 MPa·m 1/2 ) and comparable translucency as IPS e.max. This research will provide a new idea and method for the perfect matching of the fracture toughness and the aesthetic appearance of lithium disilicate glass-ceramics, and lay the foundation for its clinical applications.