Isothermal sintering with concurrent crystallisation of monodispersed and polydispersed glass particles. Part 1

We review and discuss an algorithm with no adjustable parameters to simulate the kinetics of concurrent sintering and crystallisation of monodispersed and polydispersed glass particles. The algorithm is based on the two classical sintering models of Frenkel and Mackenzie-Shuttleworth, the JMAK crystallisation theory and on our own model for polydispersed particle sintering. The input parameters are: particle size distribution (v r ), surface tension (γ), viscosity (η), number of nucleation sites (N s ) and crystal growth velocity (U). We test the algorithm at a variety of annealing temperatures using experimental data and densification rates for two powdered glasses-polydispersed alumino-borosilicate glass, which is stable against devitrification, and monodispersed cordierite glass which easily crystallises. We show that the algorithm provides a powerful simulation tool for predicting the sintering conditions of real glass powders, for any size distribution and temperature, thus minimising the number of time consuming experiments.