Soda lime silicate float glass was ion exchanged in potassium nitrate baths systematically contaminated with calcium nitrate up to 0.01 mol%. The results show that surface compression and flexural strength are dramatically depressed if the treatment is carried out in salt containing calcium nitrate in excess of 0.0015 mol%, this being related to more limited sodium-potassium exchange on the surface. The presence of calcium in the salt accounts for a “blocking” effect of the conventional Na-K exchange which is shown to be thermodynamically less favoured than Na-Ca one, especially at higher temperature.
Origin
Unknown
Journal Title
J Non Cryst Solids 458 15 February 2017 121-128
Sector
Flat glass
Class
F 3994