Measurement Of Viscosity Of Densifying Glass-Based Systems By Isothermal Cyclic Loading Dilatometry

This study describes the isothermal cyclic loading dilatometry (ICLD) technique to measure the viscosity of glass-based materials. The paper demonstrates its merit, relative to constant-load techniques in minimising the stress history effects (changes in shrinkage anisotropy and sample microstructure) that arise due to the application of an external load. A constant-load test overestimates the viscosity by an order of magnitude compared with a cyclic load test. To obtain accurate viscosity data, maximum loading rates and longer unloading periods are desirable as they reduce effects of shrinkage anisotropy on viscosity values. Representative data for a low-temperature cofired ceramic (LTCC) are reported.