This paper investigates the effect of P_2O_5 content and sintering temperature on the microstructure of lithium disilicate glass-ceramics and analyzes the relation between microstructure and mechanical properties. Specimens were prepared by hot-pressing technology, adding 1.0-4.0 mol percent P_2O_5 (G1P, G2P, G3P and G4P). Lithium disilicate (Li_2Si_2O_5), lithium metasilicate (Li_2SiO_3) and lithium orthophos-phate (Li_3PO_4) crystalline phases were detected. The morphology of Li_2Si_2O_5 crystals transformed from rod-shaped to needle-like and the mechanical properties inevitably decreased. Additionally, G1P and G2P were prepared by hot-pressing technology with sintering temperatures ranging 780-840 deg C. The results showed that sintering temperature had no significant effect on the crystalline phases and microstructure. The optimal mechanical performances (flexural strength 290 MPa; fracture toughness 3.3 MPa m~(1/2)) were obtained with 1 mol percent P_2O_5 and a sintering temperature of 820 deg C.
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