摘要 |
This invention relates to the strengthening of glass articles through an ion exchange process wherein alkali metal ions in a surface of a glass article are replaced by larger monovalent metal ions. In carrying out the process, a surface of the glass article is contacted with a source of the larger monovalent ions at an elevated temperature below the strain point of the glass for a sufficient length of time to cause the replacement of small alkali metal ions in the glass surface with the larger monovalent metal ions to a depth of at least five microns, thereby inducing a surface compression layer of this depth on the article. This invention is specifically directed to alkali aluminosilicate glasses. |