Ion Exchange Surface Hardening of Alkali Silicate Glass Using Composite Pastes

Abstract The microhardness of the surface layers of silicate glass formed by the diffusion of potassium ions from the composite paste consisting of potassium nitrate, alumina, and water is studied. Ion exchange processing using the composite paste leads to a significant increase of the microhardness of the glass surface from 550 to 850 MPa. It is found that the microhardness of the glass changes nonmonotonically, which is determined by the processes of the formation and the subsequent relaxation of the strong stress in the surface layers of the glass.