Strength of glass lenses processed in an ultrasonically stimulated chemtempering bath

Comparative experiments were performed on conventionally chemtempered lenses and ones chemtempered in an ultrasonically stimulated, slowly oscillated salt bath. With ultrasonic stimulation, a substantially shorter treatment time was found to result in greater strength and greater surface enrichment of K+ ions. The K+-rich surface layer was as deep or deeper than that found in conventionally chem-tempered lenses. The results suggest that the ultrasonic stimulation continually enriches the salt bath with K+ ions in the region of the lens surface.