Improved reliability of mechanical behavior for a thermal tempered lithium disilicate glass-ceramic by regulating the cooling rate. (February 2021)

• Record Type: Journal Article
• Authors: Li, D.; Chen, Z.X.; Zhang, Y.M.; Li, X.C.; Meng, M.; He, L.; Zhang, Z.Z.
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 114(2021)
• Publication Date: 2021-02
• Subjects: Glass-ceramics -- Lithium disilicate -- Mechanical characterization -- Tempering -- Mechanical anisotropy; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2020.104191
• Languages: English
• ISSNs: 1751-6161

Abstract

Abstract: Traditional thermal tempering was applied to lithium disilicate (LD) glass-ceramic specimens with bar-like and disc-like shapes. The tempering process was conducted by heating the specimens to a temperature below the dynamic softening point, and then rapid cooling in silicone oil with different temperatures ranging from room-temperature to 300 °C to regulate the cooling rate. Effect of the oil-temperature on mechanical behavior of the tempered glass-ceramic was investigated. For the tempering at the lower oil-temperature (e.g., at room-temperature), it was found that the LD glass-ceramic specimens with both the bar-like and disc-like shapes could be remarkably strengthen and toughen, however, obvious anisotropy in fracture toughness was displayed by the specimens with the bar-like shape. With increasing the oil-temperature up to 250 °C, the mechanical anisotropy of the bar-like specimens could be significantly alleviated without much loss of the strengthening effect. The results can provide references for improving reliability of mechanical behavior for the tempered LD glass-ceramic by regulating the cooling condition according to specimen geometry. Highlights: A lithium disilicate glass-ceramic was effectively strengthen and toughen by traditional thermal tempering. Obvious anisotropy in mechanical behavior was displayed by the tempered glass-ceramic in bar-like shape. The anisotropy could be alleviated without much loss of the strengthening effect by regulating the cooling rate.