| 摘要 |
1446572 Ion-depleted regions in glass RCA CORPORATION 27 Sept 1973 [10 Oct 1972] 45269/73 Heading C1M An alkali metal containing glass body 12 is treated to provide an ion-depleted region 42, 44 extending to at least one of two opposite surfaces 18, 20 of the glass by: (a) applying an electrode 14, 16 to each of surfaces 18, 20, one of the electrodes (14) being blocking toward introduction of mobile metal ions from the electrode to the glass and comprising a layer of conductive particles; (b) heating the glass to not more than its deformation temperature; and (c) applying a voltage between the electrodes to cause mobile metal ions to migrate from the blocked surface 18 without being replaced by other ions. The treatment temperature is preferably 150-600‹ C., and the treatment voltage 1-3000 volts D.C. or 1-3000 volts A.C. (0.001-1 H 3 ). The ion-depleted region may be up to 200,000 Š in depth. The electrodes 14, 16 are preferably porous comprising particles of average diameter not more than 1 micron, the layers being 1-5 mils. in thickness. The particles, which may be of graphite, platinum, rhodium, silicon, palladium, indium, and/or molybdenum disilicide, are preferably applied by applying a liquid suspension of the particles and evaporating the liquid. The electrodes 14, 16 are preferably contacted by graphite-felt pads 22, 24. The glass is preferably cooled during the ion-depletion to suppress surface crazing. An atmosphere of N 2 is preferably used. |
