METHOD FOR PRODUCING THREE-DIMENSIONAL SILICON CARBIDE-CONTAINING OBJECTS

Abstract

Subject-matter of the invention is a method of applying silicon carbide-containing materials to a substrate surface, and an apparatus for carrying out the method.

Claims

1. A method of applying silicon carbide-containing materials to a substrate surface, wherein a gaseous, liquid or powdery precursor material containing a silicon source and a carbon source is gasified and/or decomposed by the action of energy and at least a part of the decomposition products are deposited site-selectively on the substrate surface as a silicon carbide-containing material.

2. The method according to claim 1, wherein the silicon carbide-containing material is selected from optionally doped silicon carbide, optionally doped non-stoichiometric silicon carbide, silicon carbide alloys and mixtures thereof.

3. The method according to claim 1, wherein the silicon carbide-containing material is deposited as a layer on the substrate surface.

4. The method according to claim 1, wherein the silicon carbide-containing material is deposited on the substrate with a layer thickness in the range of 0.01 to 5 mm, 0.05 to 2 mm, or 0.1 to 1 mm.

5. The method according to claim 1, wherein: the powdery precursor material is moved in the form of at least one particle beam in the direction of the substrate surface, and is gasified and decomposed by the action of laser radiation before or on impacting the substrate, or the gaseous decomposition products are moved in the direction of the substrate, in the form of at least one particle beam.

6. The method according to claim 5, wherein the powdery precursor material or the gaseous decomposition products is or are moved toward the substrate by means of at least one nozzle.

7. The method according to claim 5, wherein: the powdery precursor material is moved in the direction of the substrate in the form of a powder beam, or the liquid precursor material is moved in atomized form or as a liquid beam in the direction of the substrate, or the gaseous precursor material or the gaseous decomposition products are moved in the direction of the substrate in the form of a gas beam.

8. The method according to claim 1, wherein the method is used for building up a three-dimensional silicon carbide-containing object layer by layer and/or for joining at least two components.

9. The method according to claim 1, wherein the method is laser deposition welding.

10. The method according to claim 9, wherein the powdery precursor material is gasified and decomposed by laser radiation in immediate proximity to the substrate surface.

11. The method according to claim 1, wherein the gasification and decomposition of the precursor material and the deposition of the silicon carbide-containing material is carried out in a protective gas atmosphere.

12. The method according to claim 5, wherein the particle beam or the particle beams is or are surrounded by a stream of protective gas.

13. A silicon carbide-containing object produced by the method of claim 1.

14. An apparatus for the site-selective deposition of silicon carbide-containing materials on a substrate surface, wherein: the apparatus comprises (c) at least one device for decomposing gaseous precursor materials or for gasifying and decomposing liquid or powdery precursor materials, wherein the precursor materials comprise at least one carbon source and at least one silicon source, and (d) at least one device for generating at least one particle beam and/or for directing a particle beam onto the substrate surface.

15. The apparatus according to claim 14, wherein the device for generating a particle beam and/or for directing a particle beam onto the substrate surface is a nozzle selected from a solid-matter nozzle and a powder nozzle.

16. The apparatus according to claim 14, wherein the device for decomposing gaseous precursor materials or for gasifying and decomposing liquid or powdery precursor materials comprises means for generating high temperatures, laser radiation or an electric arc.

17. The apparatus according to claim 16, wherein the device for decomposing gaseous precursor materials or for gasifying and decomposing liquid or powdery precursor materials comprises means for generating laser radiation.

18. The apparatus according to claim 14, wherein the apparatus comprises means for generating a protective gas atmosphere.

Description

[0194] The figures show according to

[0195] FIG. 1 an apparatus according to the invention for carrying out the method according to the invention with a powder feed arranged laterally to the laser beam,

[0196] FIG. 2 a section of an apparatus 1 according to the invention with coaxially arranged powder feeds and

[0197] FIG. 3 according to Fig. A an example of the result of the method according to the invention in the form of a generated three-dimensional object and according to B an example of the result of the implementation of the method according to the invention as a joining process.

[0198] A further subject-matter of the present invention—according to a second aspect of the present invention—is a silicon carbide-containing object obtainable by the method described above.

[0199] With the method according to the present invention, objects containing silicon carbide can be produced by means of generative manufacturing. Equally, however, it is also possible for objects or articles to be coated with a silicon carbide-containing material or for parts to be joined by means of the method according to the invention.

[0200] For further details on the silicon carbide-containing object according to the invention, reference can be made to the above explanations on the method according to the invention, which apply accordingly with respect to the silicon carbide-containing object.

[0201] Finally, according to a third aspect of the present invention, a further subject-matter of the present invention is an apparatus for the site-selective deposition of silicon carbide-containing materials on a substrate surface, wherein the apparatus comprises [0202] (a) at least one device for decomposing gaseous precursor materials or for gasifying and decomposing liquid or powdery precursor materials, wherein the precursor materials comprise at least one carbon source and at least one silicon source, and [0203] (b) at least one device for generating at least one particle beam and/or for directing a particle beam onto the substrate surface.

[0204] It is essential in the context of the present invention that the gaseous decomposition products of precursor materials containing at least one silicon source and at least one carbon source are directed site-selectively and locally limited to a substrate surface, so that on the substrate surface silicon carbide-containing materials are deposited.

[0205] As already explained, the method according to the invention is preferably carried out as laser deposition welding or as a method based on laser deposition welding. For carrying out the method, apparatuses are preferably used which largely correspond to those for powder laser deposition welding. In particular, the best results are obtained in the present invention when the particle beam is a powder beam. This ensures that a relatively large amount of material is deposited on the substrate surface in a short time, and also that the energy of the laser beam is absorbed much better by the solid precursor material than, for example, by a gaseous starting material. As a result, heating of the substrate surface is largely avoided and good deposition of material containing silicon carbide on the substrate surface is achieved.

[0206] In the context of the present invention, as previously stated, it is preferably provided that the starting materials are decomposed only in the proximity of the substrate surface, which is most easily achieved by the use of powdered starting materials.

[0207] In the context of the present invention, it is advantageously provided that the device for generating a particle beam and/or for directing a particle beam onto a substrate surface is a nozzle, in particular a solid-matter nozzle, preferably a powder nozzle. As previously stated, in the context of the present invention, best results are obtained when the starting materials or the precursor materials are in powder form.

[0208] In the context of the present invention, it is further advantageously provided that the device for decomposition of gaseous starting compounds or for gasification and decomposition of liquid or powdery starting materials comprise means for generating high temperatures, in particular means for generating laser radiation or means for generating an electric arc.

[0209] By using an electric arc or laser radiation, preferably laser radiation, the starting materials can be easily decomposed in the proximity of the substrate surface.

[0210] According to a more preferred embodiment of the present invention, the device for decomposing gaseous precursor materials or for gasifying and decomposing liquid or powder precursor materials comprises means for generating laser radiation. Preferably, the device for decomposition of gaseous precursor compounds or for gasification and decomposition of liquid or powdery precursor materials is a laser.

[0211] Furthermore, it is usually provided that the apparatus comprises means for generating a protective gas atmosphere. To prevent undesired oxidation of the gaseous decomposition products by atmospheric oxygen, the method according to the invention is usually carried out in an inert gas atmosphere. Either it can be provided that a part of the apparatus, in particular the part containing the substrate, comprises a protective gas atmosphere. Alternatively and more preferably, however, it is provided that the particle beam, for example the powder beam, is surrounded by a protective gas and thus a protective gas atmosphere is generated locally, in particular in the region of the gasification and decomposition of the starting materials.

[0212] For further details, reference can be made to the above explanations on the further aspects of the invention, which apply accordingly with respect to the apparatus according to the present invention.

[0213] The subject-matter of the present invention is illustrated below by way of example and in a non-limiting manner by the figure description.

[0214] FIG. 1 shows an apparatus according to the invention with a device for gasification and/or decomposition of precursor materials, in particular a device 2 for generating laser beams 3. Furthermore, the apparatus 1 comprises at least one device 4 for generating a particle stream from gaseous, liquid or solid precursor materials 5. Preferably, the particle beam is formed by powdery precursor materials. However, all precursor materials have in common that they always comprise at least one silicon source and one carbon source as well as possibly also alloying elements or doping elements or compounds thereof.

[0215] The laser beams 3 and the particle beam of the precursor material 5 are directed onto the surface 7 of a substrate 8 in such a way that the laser beams 3 strike the particle beam in the immediate proximity of the substrate surface 7. As a result, the precursor materials 5 contained in the particle beam are decomposed or gasified and decomposed, thereby obtaining reactive fragments which are deposited as a desired silicon carbide material in the form of a layer of a silicon carbide-containing material 6 on the substrate surface 7.

[0216] The thickness of the layer of silicon carbide-containing material 6 may be between 0.01 to 5 mm, in particular 0.5 to 2 mm, preferably 0.1 to 1 mm.

[0217] The method according to the invention with the aid of the apparatus 1 thus permits a site-selective and locally sharply limited application of a layer 6 of a silicon carbide-containing material. By movement, in particular motion, of the substrate 8, or of the devices 2 and 4, either a three-dimensional object with a multilayer structure can be obtained or the substrate surface 7 can be coated in a desired manner with a layer of the silicon carbide-containing material 6.

[0218] FIG. 2 shows an alternative design of the apparatus 1 according to the invention. In particular, FIG. 2 shows a section of an apparatus 1. The apparatus 1 comprises a device 2 for gasification and/or decomposition of gaseous, liquid or powdery precursor materials 5, wherein preferably the device 2 for gasification and/or decomposition of the starting materials is designed in the form of a device for generating laser beams 2.

[0219] The apparatus 1 further comprises devices 4 for generating a particle beam, in particular from gaseous, liquid or powdery starting materials, in particular powdery starting materials. With the embodiments shown in FIG. 2, the devices 2 and 4 are integrated together in a nozzle head which is preferably designed to be movable, in particular designed to be movable.

[0220] The particle beam from the precursor material 5, in particular the particle beams 5, surround the laser beam 3 and cross it shortly before impacting the surface 7 of a substrate 8, whereby the precursor materials are decomposed and a layer of a silicon carbide-containing material 6 is deposited on the substrate surface 7.

[0221] The apparatus 1 further comprises means 9, in particular nozzles, for generating a protective gas atmosphere, in particular a stream of protective gas 10. The stream of protective gas 10 surrounds or envelops the particle beam(s) of the precursor material 5 and thus enables decomposition of the starting materials in a protective gas atmosphere, in particular an argon atmosphere.

[0222] Finally, FIG. 3 shows various possible applications of the apparatus 1 according to the invention and the method according to the invention. In particular, three-dimensional objects can be obtained by repeated application of layers of silicon carbide-containing material 6, as shown in alternative A. Similarly, it is also possible to bond components, in particular substrates 8a and 8b, via their surfaces, in particular their surfaces 7a and 7b, by applying the silicon carbide-containing material 6.

TABLE-US-00001 Reference signs: 1 Apparatus 2 Device for generating laser beams 3 Laser beams 4 Device for generating a particle beam 5 Precursor material 6 Silicon carbide-containing material 7 Substrate surface 8 Substrate