Ceramic or glass-ceramic article and methods for producing such article

Ceramic or glass-ceramic article comprising

• a set of adjacent, joined layers of ceramic or glass-ceramic material, wherein said layers have a thickness in the range of from 5 to 200 μm,
• and/or
• a set of adjacent, joined tracks of ceramic or glass-ceramic material,
• wherein said article has a bending strength of at least 25 MPa, preferably of at least 250 MPa and more preferably of at least 500 MPa.

Method of producing a ceramic article comprising the steps of:

• (a) providing a powder or a powder mixture comprising 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 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 step (c) one, two, a plurality or all regions are preheated,
• wherein the method comprises the successive repetition of steps (a), (b), (d), and (e), wherein the surface of the layer produced by a preceding series of steps (a) to (e) is used in a respective subsequent step (b) as surface for the following layer
• wherein said powder or powder mixture comprises components that form an eutectic system with each other,
• wherein at least 50 percent by weight, preferably at least 70 percent by weight of said powder or powder mixture consist of one or more compounds selected from the group consisting of Al2O3, ZrO2, Y2O3, Na2O, Nb2O5, La2O3, CaO, SrO, CeO2, MgO, SiO2, TiO2, Cr2O3, CuO, the mixed oxides thereof, SiC, TiC, Si3N4 and AlN,
• and wherein for each component of said eutectic system the fraction by weight of the component, based on the weight of the eutectic system in the powder or powder mixture, is at least 25% of the fraction by weight of the same component in the eutectic mixture of said eutectic system.