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PubMed · 12516081

Effect of processing variables on texture development in a mica-based glass-ceramic.

I L Denry·G Baranta·J A Holloway·P K Gupta
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Abstract

The purpose of this study was primarily to determine the feasibility of heat-pressing a mica-based glass-ceramic with the use of commercially available dental equipment, and secondly to evaluate the effect of various processing variables on the degree of crystal alignment in the pressed glass-ceramic. The hypotheses were that the mica-based glass-ceramic could be successfully heat-pressed and that some degree of crystal orientation would be obtained, depending on the processing variables. The glass composition was melted at 1400 degrees C for 2 h and cast into 12 x 60-mm rods. Ingots (10 x 12 mm) were cut from the glass rods, heat treated, and heat-pressed under various conditions. The microstructure of the pressed specimens was investigated by SEM and compared to that of heat-treated controls. The length of Vickers-induced cracks was measured on heat-pressed specimens and heat-treated controls. The results showed that mica-based glass-ceramics could be successfully pressed with the use of commercially available dental equipment. The resulting degree of crystal alignment (texture) along the direction of pressing varied between 35 +/- 6 and 79 +/- 6. There was a linear relationship between the degree of texture and the apparent aspect ratio of the mica platelets. A significant decrease in the length of the Vickers-induced cracks in the direction perpendicular to pressing was observed, associated with an increase in length in the direction of pressing.

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Aluminum SilicatesBiocompatible MaterialsCeramicsCrystallizationHot TemperatureMaterials TestingMicroscopy, Electron, ScanningSurface PropertiesX-Ray DiffractionJournal ArticleResearch Support, N.I.H., Extramural

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I L Denry, G Baranta, J A Holloway, P K Gupta. 2003-02-15. Effect of processing variables on texture development in a mica-based glass-ceramic.. https://doi.org/10.1002/jbm.b.10514

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