Internal Stresses in Glass-Crystalline Materials Based on beta -Eucryptite and beta -Spodumene Solid Solutions.

An X-ray study was made of the internal stresses in glass-ceramic materials based on beta -eucryptite and beta -spodumene solid solutions. The measured stresses were found to be much lower than those calculated on the basis of the well-known difference between the thermal expansion coefficients of the crystalline phase and the residual glass. This discrepancy is attributed to the formation of a network of cracks which must be especially developed in glass-ceramic materials based on beta -eucryptite solid solutions.