Chemical Strengthening of Glass-Ceramics in the System Li2O-Al2O3-SiO2 |
| |
Authors: | B. R. KARSTETTER R. O. VOSS |
| |
Affiliation: | Technical Staffs Division, Corning Glass Works, Corning, New York 14830 |
| |
Abstract: | Fine-grained glass-ceramics containing a large proportion of β-spodumene solid-solution crystals were strengthened by immersion in molten sodium and potassium salt baths. An ion-exchange reaction placed sodium or potassium ions in lithium ion sites in the β-spodumene structure. The resultant "crowding" of the structure produced a surface compressive layer. In this system, strengths (modulus of rupture on abraded specimens) in excess of 100,000 psi were realized. In a similar manner, stuffed β-quartz solid-solution glass-ceramics derived from the crystallization of Li2O-Al2O3-SiO2 glasses containing an appropriate amount of nucleating agent were strengthened by K+-for-Li+ exchange. Stable β-quartz solid-solution glass-ceramics were strengthened by Na+-for-Li+ exchange, but no significant increase in strength was obtained in the metastable β-quartz materials. |
| |
Keywords: | |
|
|