Preparation and Properties of MgO-Al_2O_3-SiO_2 Glass-ceramics

Abstract: Glass-ceramics, also known as (Glass Ceramics), as a new functional materials and structural materials, for its excellent optical, electrical, magnetic, biological, and chemical properties in micro-electronics technology, biomedical, defense advanced technology, machinery manufacturing and other fields have been widely used. Cordierite-based glass-ceramic is a high-strength glass-ceramics. Because of its low production costs, abundant raw materials, low dielectric constant, low coefficient of thermal expansion, high mechanical strength and good electrical insulation properties, is considered promising engineering materials and dielectric materials widely used Therefore, in it's research and application development has been very active. In this paper, the application of deep-sea buoyancy material against the backdrop of glass beads, to explore a high-strength glass-ceramic filler as a buoyancy material—glass-ceramic beads preparation materials, to increase the use of the depth of the buoyancy material.In this paper, MgO-Al_2O_3-SiO_2 based glass composition, the system studied the system and the preparation of glass crystallization behavior; discussed the nucleating agent of the Department of the glass crystallization properties; analysis of nuclear and chemical in different time ,nucleation temperature, crystallization time, crystallization temperature under the glass-ceramic materials have mechanical properties and microstructure; and come to the preparation of high-performance glass-ceramic process parameters better.The results show that the glass in MgO-Al_2O_3-SiO_2/B_2O_3 have relatively low melting temperature, suitable for glass-ceramic prepared by melting; ZrO_2-TiO_2 composite nucleating agent on the MgO-Al_2O_3-SiO_2 glass with the crystallization role in promoting effective use of ratio (2% ZrO_2 +3% TiO_2) composite nucleating agent prepared MgO-Al_2O_3-SiO_2 glass-ceramics department, the main crystalline phase for theα-cordierite, and small grains, uniform and is conducive to the improvement of strength of glass-ceramics; nucleation temperature, nucleation time and crystallization temperature, crystallization time on the mechanical properties of glass-ceramics have a strong impact; of MgO-Al_2O_3-SiO_2 glass, mixing (2% ZrO_2 +3% TiO_2) for the crystal nucleating agent, in 1550℃under the glass prepared by melt the sample, the sample in 600℃, 4h nuclear and chemical processing, in 1100℃, 4h crystallization treatment, get better performance with the cordierite-based glass-ceramics, and its flexural strength is 182MPa, Vickers hardness is 12.89 GPa, fracture toughness is 6.61 MPam~(1/2)…
Key words: glass-ceramics; nucleation; crystallization; Nucleation agent; cordierite

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