Physical Interpretation Of Creep and Strain Recovery of a Glass Ceramic Near Glass Transition Temperature

Abstract

The anelastic and viscoplastic behaviours of a glass ceramic have been studied in relation with the microstructure during structural relaxation, early stages of crystals nucleation and in isoconfigurational and metastable states. In order to interpret the physical processus resulting in non-elastic deformation, a physical model of deformation based on the concept of “defects” and of correlated atomic movements has been used. From the model, the compliance J(t) of creep and strain recovery were described by equations having three physical parameters-i) A: parameter proportional to the concentration of defects-ii) ^τmax : characteristic time-iii) b: parameter characterizing the effectiveness of correlation effects (0<b<l). There is a good agreement between experimental and calculated creep curves. In addition, the evolution of A, ^τmax and b with the microstructure change of glass could be interpreted in a consistent way.