STRENGTH-STRUCTURE RELATIONSHIPS IN VITREOUS INFRARED MATERIALS
Final rept. 1 Apr 1967-31 Mar 1968
MICHIGAN UNIV ANN ARBOR INST OF SCIENCE AND TECHNOLOGY
Pagination or Media Count:
Investigation of basic strength and structure relationships in vitreous materials revealed that a linear relationship existed between the inherent breaking strength and the microelasticity of the three glass systems which were examined, silicates, calcium aluminates, and arsenic trisulfides. Using this relationship, it is possible to explain the wide spread observed in breaking-strength data in terms of microelasticity variability and to utilize these linear curves to analyze subtle alterations in the basic structure and in the surface conditions of glasses. Regular polishing techniques as well as surface abrasion and mechanical damage produced quite drastic changes in the microelasticity characteristics of the glasses. The effect of melting conditions was examined in arsenic trisulfides, and data are presented showing an increase in strength after a melting treatment designed to reduce optical absorption bands in the material. The importance of surface polishing in altering microelasticity characteristics was corroborated in the studies with arsenic trisulfides. Irtran materials were also examined. Irtran type no. 1 disclosed a structure more characteristic of a vitreous material than of a polycrystalline, which indicates that under certain conditions the hot press type of network may approach some degree of amorphism. Data concerning the relationship between shear modulus values determined by sound-velocity measurements and the flaw parameters in the three basic systems are also presented.
- Ceramics, Refractories and Glass
- Infrared Detection and Detectors