Internal Friction of Simple Alkali Silicate Glasses Containing Alkaline‐Earth Oxides: II, Interpretation and Discussion

Abstract

The results of internal friction measurements on simple three‐component glasses that were reported in Part I of this paper are discussed. From a consideration of the basic equations governing internal friction and examination of the results of other investigators, a basis of interpretation is developed. It is shown that changes in peak‐temperature position can be explained by changes in the activation energy of the process causing the peak. A change in peak height not accompanied by a change in the shape of the peak is shown to be due to a change in the concentration of the relaxation mechanisms. Using this information the changes in the peaks due to composition variations are explained on a structural basis. A mechanism is also suggested to explain the new high‐temperature peak. A critical examination of the measurements on alkali‐free and phosphate glasses leads to the conclusion that it may be necessary to re‐evaluate some of the concepts concerning the low‐temperature peak in alkali silicate glasses.