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CONTROL OF CRAZING IN SANITARY WARE GLAZES BY MAYER AND HAVAS COEFFICIENT OF EXPANSION FACTORS *
Author(s) -
Knecht A. O.
Publication year - 1940
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.1151-2916.1940.tb14200.x
Subject(s) - glaze , crazing , materials science , mineralogy , thermal expansion , raw material , portlandite , composite material , metallurgy , geology , chemistry , polymer , cement , ceramic , portland cement , organic chemistry
A bstract A brief history of glaze literature on coefficient of expansion and a short description of methods of determination are given. Using the factors of Mayer and Havas to calculate the coefficient of expansion of glazes from the percentage weights of their oxides, factors were calculated for glaze raw materials. Instead of the empirical formulas for raw materials, chemical analyses supplied by dealers of glaze materials were used. A series of glazes, starting with a high coefficient and gradually decreasing in coefficient, was tested. After determining from this series the calculated coefficient of the noncrazing glaze, a series was made in which the composition was varied and the coefficient was kept constant. Glazes of low coefficient did not craze. No crazing resulted when the composition of the glazes was varied and the calculated coefficient was kept constant. This method is a valuable means of controlling crazing in sanitary glazes because of its simplicity, the economy of experimental equipment, and the relatively short time required to complete the tests.