| 主权项 |
1. Method of producing a ceramic or glass-ceramic article from a powder or powder mixture, comprising the steps of:
(a) providing the powder or powder mixture comprising ceramic or glass-ceramic material, (b) depositing a layer of said powder or powder mixture on a surface, (d) heating at least one region of said layer by means of an energy beam or a plurality of energy beams to a maximum temperature such that at least a part of said ceramic or glass-ceramic material in said at least one region is melted, (e) cooling said at least one region of said layer so that at least part of the material melted in step (d) is solidified, such that the layer is joined with said surface in said at least one region, wherein the method includes a preheating step (c) wherein in the step (c) one or more of the at least one regions are, preheated, wherein the method comprises successive repetition of the steps (a), (b), (c), (d), and (e) to produce the ceramic or glass-ceramic article, wherein a successive surface of the layer produced by a preceding series of the steps (a), (b), (c), (d), and (e) is used in a respective subsequent step (b) as a surface for the following layer, wherein said powder or powder mixture comprises components that form an eutectic system with each other during solidification in the step (e), wherein, for each repetition, the step (a) starts before the step (b), the step (b) starts before the step (c), the step (c) starts before the step (d), and the step (d) starts before the step (e), and wherein at least 50 percent by weight of said powder or powder mixture is the eutectic system, wherein each of the components is selected from the group consisting of Al2O3, ZrO2, Y2O3, Na2O, Nb2O5, La2O3, CaO, SrO, CeO2, MgO, TiO2, Cr2O3, CuO, mixed oxides thereof, SiC, TiC, Si3N4 and AlN. |
