3D-Metal-Printing Method and Arrangement Therefor

Abstract

A 3D-metal-printing method applies material layer-by-layer and selectively locally heats predetermined points above a sintering or melting temperature of the powder and sinters or fuses the melted points with the underlying layer and optionally tempers the points. The starting material layer and optionally at least one underlying layer is preheated to a temperature with a predetermined difference to the melting temperature, and near IR radiation is sequentially irradiated in sections into partial sections of the total area of the respective starting material layer, wherein the selective local heating above the sintering or melting temperature is carried out in each case for predetermined points within a preheated partial section.

Description

Claims

1. 3D-metal-printing method for producing a spatial metal product essentially from a metal powder or metal filaments; wherein the powder or the filaments is/are built up layer-by-layer by applying starting material layers to a respective previously produced layer and selectively locally heating predetermined points of the layer above a sintering or melting temperature of the powder and sintering or fusing the melted points with the underlying layer and optionally tempering the points;wherein the respective newly applied starting material layer and optionally at least one underlying layer is preheated to a temperature with a predetermined difference to the melting temperature by irradiation in a flat or migrating manner of near IR radiation, in particular with a radiation density maximum in the wavelength range between 0.8 and 1.5 µm, and/or is post-treated following the local heating of predetermined points for thermal stress equalization; andwherein the near IR radiation is sequentially irradiated in sections into partial sections of the total area of the respective starting material layer, wherein the selective local heating above the sintering or melting temperature is carried out in each case for predetermined points within a preheated partial section.

2. 3D-metal-printing method according to claim 1, wherein the power density of the near IR radiation irradiated over a surface is above 1 MW/m2.

3. 3D-metal-printing method according to claim 1, wherein the radiation of at least one halogen radiator, in particular a plurality of halogen radiators, with a radiator temperature in particular also in the range of 2900 K to 3200 K is used as near IR radiation.

4. 3D-metal-printing method according to claim 1, wherein the selective local heating of predetermined points is affected by scanning the starting material layer with an electron or laser beam.

5. 3D-metal-printing method according to claim 1, wherein preheating to a material-specific preset temperature, in particular in the range between 600 and 1100° C., more particularly in the range between 700 and 1000° C., is carried out and is controlled in particular by time and/or radiation density control of the irradiation of the near IR radiation.

6. A system for 3D metal printing, comprising: a worktable as a base for layer-by-layer structure of a spatial metal product;a powder application device for sequential application of starting material layers of a metal powder or starting material filaments in the area of the worktable;a surface heating device for surface heating of each new starting material layer for preheating or thermal post-treatment, the surface-heating device having an NIR irradiation device for irradiating near IR radiation, in particular with a radiation density maximum in the wavelength range between 0.8 and 1.5 µm, onto a predetermined surface in the region of the worktable; anda mechanism providing selective local heating of predetermined points of the new starting material layer above a sintering or melting temperature of the metal powder;wherein the surface heating device is designed to radiate the near IR radiation sequentially into subsections of the total area of the respective initial material layer; andwherein the means of inducing selective local heating are configured to induce local heating at specified points within one or another of the pre-heated subsections.

7. System according to claim 6, wherein the mechanism providing selective local heating of predetermined points of a previously applied starting material layer comprises a laser with a downstream scanner for point-by-point irradiation of near NIR radiation or visible light in the long-wave range onto the predetermined points.

8. System according to claim 6, wherein the mechanism providing selective local heating of predetermined points of a previously applied starting material layer comprises an electron beam generator for the point-by-point irradiation of electron radiation onto the predetermined points, and the arrangement is arranged in a vacuum chamber subjected to a high vacuum.

9. System according to claim 6, wherein the NIR irradiation device comprises at least one halogen radiator, in particular a plurality of halogen radiators, with a reflector associated such that the radiation of the or each infrared radiator is concentrated in the direction towards the worktable.

10. System according to claim 9, wherein the halogen radiator or the plurality of halogen radiators with associated reflector is mounted above the worktable so as to be movable in at least one axial direction of an XY plane.

11. System according to claim 9, wherein the halogen radiator or radiators is/are designed for operation at a radiator temperature in the range of 2900 K to 3200 K.