Why is Gorilla Glass so much stronger than other chemically strengthened glass?

July 10, 2012 2:04 PM

How does the High Ion Exchange (HIE) process get such a deep compressive layer in the glass strengthening process used in Gorilla Glass?

Normal chemically strengthened glass has a compressive layer that is on the order of 5 microns or so deep. Gorilla Glass, which is produced using Abrisa Technologies' HIE process claims a depth of greater than 40 microns.

What is different about their process? All the chemical strengthening processes I've seen use a molten potassium bath to create the compressive layer, just like Abrisa. So how do they get the depth? Is their bath hotter? Do they keep the glass immersed for a much longer time?

posted by blurker to Science & Nature (2 answers total)

This master's thesis [pdf] discusses HIE and notes that longer soak times and hotter temperatures both increase the depth of ion exchange (see pages 11-13). Depth goes up with the square root of soak time, so there's a practical limit to how much that will help, and there are upper bounds on the temperature of the bath as well. The author indicates that these factors mean that ion exchange depth is limited to "a few 10's of microns for most commercial glass," which is within Abrisa's range. So it could just be a combination of hotter and longer.
posted by jedicus at 2:22 PM on July 10, 2012

Gorilla Glass is so last week. Gorilla Glass 2 claimes a depth of greater than 50 microns.

Given what you do for a living, can't you beat this information directly out of Corning?
posted by Mad_Carew at 9:39 AM on July 18, 2012