Patent DE-102010029078-A1 (DE)
Title: Producing an article by layer-wise structures made of powdered metallic or ceramic material, comprises individually preparing material powder layers subsequent to each other on a support, and location-selectively solidifying each layer
Inventor: FOCKELE MATTHIAS
IPC: B22F3/105
Filed: 2010-05-18
Abstract: The method for producing an article by layer-wise structures made of powdered metallic or ceramic material, comprises individually preparing material powder layers subsequent to each other on a support (6), and location-selectively solidifying each layer by melting or optionally sintering the material powder at a predetermined position in according with geometrical description data of the article to be produced and by introducing radiation energy, where the preparation step comprises introducing the material powder on the support and leveling the material powder for producing a powder layer. The method for producing an article by layer-wise structures made of powdered metallic or ceramic material, comprises individually preparing material powder layers subsequent to each other on a support (6), and location-selectively solidifying each layer by melting or optionally sintering the material powder at a predetermined position in according with geometrical description data of the article to be produced and by introducing radiation energy, where the preparation step comprises introducing the material powder on the support and leveling the material powder for producing a powder layer with a determined target layer thickness. The material powder is used for the preparation of the material powder layers and contains upto a minimum portion of powder particle with a grain size that is larger than the target layer thickness. The mass portion of powder particles is larger than 2%, where the powder particles have a grain size larger than the target layer thickness. The mass portion of the powder particles, which have grain size larger than the target layer thickness of the material powder layer, is less than 5%, where the grain size of the largest powder particle is greater than 1.5 times of target layer thickness and less than 5 times of target layer thickness. The leveling step takes place under the use of a stripping tool, which is moved with its lower edge in a horizontal plane over the support to level a concerned material powder layer, where the vertical distance between the support and the lower edge of the stripping tool is adjusted around the measurement of the target layer thickness in an enlarged manner before the stripping tool is moved towards the leveling of a new material powder layer over the support. The stripping tool is moved with its lower edge in an equally remaining horizontal plane over the support during the leveling process. The support is lowered around the measurement of the target layer thickness against the horizontal height plane before the stripping tool is moved towards the leveling of the new material powder layer over the support. A zone-wise elastically flexible evasive stripper is used as the stripping tool for leveling the material powder layers. The material powder is used with grain size of 0 to larger than 90 mm but less than 120 mm containing particle size distribution for the target layer thicknesses of 20-60 mm.