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Calibration and Use of the Heating Microscope for Indirect Evaluation of the Viscosity and Meltability of Archeological Glasses
Author(s) -
Montanari Francesco,
Miselli Paola,
Leonelli Cristina,
Boschetti Cristina,
Henderson Julian,
Baraldi Pietro
Publication year - 2014
Publication title -
international journal of applied glass science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 34
eISSN - 2041-1294
pISSN - 2041-1286
DOI - 10.1111/ijag.12038
Subject(s) - materials science , microscope , viscosity , optical microscope , composite material , calibration , vitrification , thermal , ceramic , mineralogy , work (physics) , base (topology) , optics , scanning electron microscope , geology , thermodynamics , statistics , physics , mathematics , medicine , mathematical analysis , andrology
The heating microscope is a widely used instrument in many industrial applications, especially in the ceramic field, to obtain information on the sintering behavior and, indirectly, on the viscosity curve of glass. It is therefore important for the study of glass technology. Usually, heating microscopes work by taking images of the sample outline, during a preset thermal cycle, which define five characteristic temperatures corresponding to particular shapes of the specimen. The first two characteristic temperatures can also be extracted from the sintering curves provided by the instrument. In agreement with three published models, the five temperatures are associated with five viscosity values, producing the two best‐fitting plots (Log 10 (η) – T ). In this work, the heating microscope was calibrated using a glass with known properties, to determine the most reliable model, so that it can be applied successfully in the field of archeological science. The selected methodologies were used to analyze two opacified Roman mosaic glass tesserae excavated in Pompeii, previously characterized chemically. A Pompeiian transparent glass, sampled from a large block of base (raw) glass, and its experimental reproduction were also studied. Finally, the relationship between the opacifiers and the thermal behavior of base glass was investigated.