Abstract:
The invention relates to a method to increase the strength of a form body of lithium silicate glass ceramic, which after it has a desired end geometry and after the application of a material which influences its surface to form a coating, is subject to a heat treatment. To create a surface compressive stress through the replacement of lithium ions by alkali ions of greater diameter at least that region not covered by the application layer is covered by a melt or paste consisting of or containing a salt of an alkali metal with ions of greater diameter and the form body is in contact with the melt or paste for a period of time t at a temperature T and the melt or paste is subsequently removed from the form body.
Abstract:
The invention relates to a support body (10) for a blank, whereby the support body possesses a receiving opening (13) for the blank that is surrounded by an inner circumferential surface (14), which terminates in an upper and a lower edge (26, 28), and whereby a blank fixed in position within the support body is bonded to the latter by means of an adhesive agent. In order to be able to easily introduce the adhesive agent into a gap between the blank and the support body it is intended that the inner circumferential surface (14) possesses at least one depression (18, 20, 22, 24) and/or elevation extending to accommodate the adhesive agent.