Schott Ag

Inge Burger

Jochen Alkemper

Oliver Hochrein

Gunther Paulus

Gordon Kissl

Irmgard Westenberger

Gerd Rudas

Katharina Alt

A glass element is provided that is made of a glass having SiO, AlO, BO, and NaO. The glass has a scratch tolerance that when scratches of 1 mm length are introduced using a Knoop diamond indenter which presses upon a surface of the glass with a force of 4 Newton and is displaced along the surface with a traverse speed of 0.4 mm/s, not more than 20% of the scratches have a noticeable width including visible chipping of more than 25 &#x3bc;m. In some embodiments, the glass, after chemical tempering, has sodium ions that are at least partially exchanged for potassium ions so that a compressive stress zone is provided at the surface of the glass. The compressive stress is at least 700 MPa and an exchange depth of alkali ions is at least 25 &#x3bc;m.

Glass element with high scratch tolerance

Growing community of inventors

Wiesbaden, Germany

Inge Burger