Critical cooling rate calculations for glass formation

An assessment is made of the various factors which are involved in the calculation of critical cooling rates for glass formation. In particular, attention is focused upon the sensitivity of computed critical cooling rates R c to various approximations and uncertainties in physical parameter data. SiO 2 and GeO 2 are chosen as model systems to illustrate the major features. It is shown that R c is rather insensitive to the mode of computation of the volume fraction crystallized, but is quite dddependent upon the material parameters which enter into the nucleation and crystal growth expressions.