摘要 |
A glass sheet, the composition of which is of the lithium aluminosilicate type and includes at most 1% by weight of sodium oxide, the thickness of which is at most 2 mm, having a surface region under compression obtained by ion exchange and a central region under tension, such that the flexural stress at break in a ring-on-tripod test is at least 50 MPa, after Vickers indentation under a load of 120 N. |