Publication Date:
2012-04-15
Description:
The Weibull modulus, flexural strength, fracture toughness, Vickers microhardness, and chemical durability of sintered Li 2 O–SiO 2 glass ceramic specimens doped with P 2 O 5 or ZrO 2 were evaluated in accordance with the norm of EN ISO 6872. Peak crystallization temperatures, crystalline phases, and microstructure were characterized by means of differential thermal analysis, X-ray diffraction, and scanning electron microscopy methods, respectively. Phase formation induced by the addition of P 2 O 5 led to precipitation of Li 3 PO 4 , which in turn caused more intensive crystallization of Li 2 SiO 3 . The high-temperature crystalline phase Li 2 Si 2 O 5 was precipitated more intensively in P 2 O 5 containing specimens resulting in an interlocked microstructure of needle like disilicate crystals. Therefore, the P-doped glass ceramic exhibited the optimum mechanical and chemical properties (i.e., m =15, σ f =181 ± 15 MPa, K I C =1.94 ± 0.19 MPa m 1/2 , H v =3.7 ± 1.1 GPa, chemical solubility=53 ± 9 μg/cm 2 )
Print ISSN:
1546-542X
Electronic ISSN:
1744-7402
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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