REINFORCEMENT OF GLASS

PURPOSE:To obtain a glass excellent in radiation resistance, useful as e.g., a wear-resistant material by irradiating a glass having chemical bond between Si and O with N ion-contg. ionic beams to form a layer having bond between Si and N excellent in physical, mechanical and chemical properties. CONSTITUTION:Firstly, N ions are formed, through e.g., a high-frequency discharge, in a vacuum vessel e.g., 10-10Torr in pressure and >=10% in partial pressure of a gaseous N-contg. compound (e.g., N2, NH3). Thence, ion beams accelerated with an accelerating voltage of >=ca. 100V (pref. 1KV-5MV) are irradiated on the surface of a glass having chemical bond between Si and O (e.g., silica glass) heated up to the softening point (e.g., 0-1,000 deg.C) until a desired thickness of a layer having Si-N bond and a desired introduction of N-atom are accomplished, and furthermore, if needed, followed by heat treatment (e.g., at 100-150 deg.C for 5-200min.), thus reinforcing the glass.