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STUDY OF TIME AND TEMPERATURE EFFECTS ON GLASS IN ANNEALING RANGE *
Author(s) -
Collyer P. W.
Publication year - 1947
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1947.tb18863.x
Subject(s) - borosilicate glass , refractive index , thermodynamics , annealing (glass) , rate equation , atmospheric temperature range , degree (music) , mathematics , constant (computer programming) , range (aeronautics) , materials science , mineralogy , chemistry , physics , optics , composite material , kinetics , classical mechanics , computer science , acoustics , programming language
A bstract Samples of a melt of borosilicate glass have been treated by holding them for periods up to 500 hours at constant temperature. The equilibrium condition was attained to a very close approximation at several temperatures. This nearness of approach makes possible the comparison of various proposed equations relating the rate of change of physical properties to their equilibrium values. Refractive index was the characteristic used to indicate the rate of approach to equilibrium conditions. It is shown that the equations expressing dn/dt as first or second degree functions of ( n e ‐n ) do not seem to fit the present data. The equation of Tool is then transformed to give equation (7) (of the text) for the rate of change of index.It is shown that this equation appears to represent adequately the rates of change of index derived from the present data and also those of previous investigators.