Glass transition and instant freezing theories - A comparison of frozen-intemper stresses

For many practical cases of tempering the temper stresses calculated by ins tant freezing theories are sufficient and in good agreement with experiment s. The auhors give a brief summary of the theories by Adams and Williamson, Bartenev and Indenbom and discuss their numerical implementation. For exam ple, frozen-in temper stresses are calculated and discussed within the mode l of a symmetrically cooled, infinite glass plate. Based on the numerical s olution of the heat conduction equation with a given heat transfer coeffici ent, especially the influence of the initial temperature of quenching is in vestigated. Furthermore, a numerical algorithm is presented to calculate th e temporal evolution of the permanent temper stresses for Indenbom's theory . Finally, as a practical example, residual stresses are determined in the surface of a tempered glass-particle composite system.