An Assessment Of Glass Stability Criteria

Several of the commonly used criteria for gauging glass stability are examined for the case of bulk crystallisation of relatively unstable compositions. The qualitative and quantitative usefulness of these criteria are assessed by comparisons with the computed values of the actual times required to crystallise a specified volume fraction for a thermal history appropriate for fibre drawing. The stability indices are altered by changing the physical parameters which control the crystal nucleation and growth processes. It is found that the standard measures of glass stability are often, but not always, qualitatively useful.