Corning Incorporated
Glasses having improved toughness and scratch resistance

Abstract:

A silicate glass that is tough and scratch resistant. The toughness is increased by minimizing the number of non-bridging oxygen atoms in the glass. In one embodiment, the silicate glass is an aluminoborosilicate glass in which -15 mol %.ltoreq.(R.sub.2O+R'O--Al.sub.2O.sub.3--ZrO.sub.2)--B.sub.2O.sub.3.ltore- q.4 mol %, where R is one of Li, Na, K, Rb, and Cs, and R' is one of Mg, Ca, Sr, and Ba.