Process and a device for producing ceramic molds

• US 6,827,988 B2
• Filed: 06/13/2002
• Issued: 12/07/2004
• Est. Priority Date: 06/15/2001
• Status: Expired due to Fees

• Current Assignee: Ceramic Institut Clausthal GmbH
• Original Assignee: Technische Universitaet Clausthal
• Inventors: Heinrich, Jurgen G., Krause, Tobias, Engler, Sven, Gunster, Jens
• Primary Examiner(s): CAMERON, ERMA C
• Application Number:
  US10/170,185
• Publication Number:
  US 20030001313A1
• Time in Patent Office: 908 Days
• Field of Search: 427/595, 427/596
• US Class Current: 427/596
• CPC Class Codes: B05C 5/0254 Coating heads with slot-shaped outlet B05C5/0283 takes precedence
• CPC Class Codes: B28B 1/001 Rapid manufacturing of 3D objects by additive depositing, agglomerating or laminating of material selective deposition modelling of metallic powder B22F10/00; rapid manufacturing of 3D objects in general and in particular of plastics B29C64/00
• CPC Class Codes: B32B 18/00 Layered products essentially comprising ceramics, e.g. refractory products
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: C04B 2235/656 characterised by specific heating conditions during heat treatment
• CPC Class Codes: C04B 2235/665 Local sintering, e.g. laser sintering
• CPC Class Codes: C04B 2237/30 Composition of layers of ceramic laminates or of ceramic or metallic articles to be joined by heating, e.g. Si substrates
• CPC Class Codes: C04B 2237/341 Silica or silicates
• CPC Class Codes: C04B 2237/343 Alumina or aluminates
• CPC Class Codes: C04B 2237/366 Aluminium nitride
• CPC Class Codes: C04B 2237/368 Silicon nitride
• CPC Class Codes: C04B 2237/704 of one or more of the ceramic layers or articles
• CPC Class Codes: C04B 33/24 Manufacture of porcelain or white ware
• CPC Class Codes: C04B 33/28 Slip casting mechanical features B28B1/26
• CPC Class Codes: C04B 33/32 Burning methods
• CPC Class Codes: C04B 35/62218 obtaining ceramic films, e.g. by using temporary supports
• CPC Class Codes: C04B 35/64 Burning or sintering processes C04B33/32 takes precedence ; powder metallurgy B22F
• CPC Class Codes: C04B 35/653 Processes involving a melting step

Abstract

Ceramic molds are produced by sintering selected portions of a ceramic material with a laser beam to form the mold. The process involves application of at least one layer of a liquid suspension or plastic mass, drying the applied layer, and sintering the dried layer with the laser beam at selected areas to form the mold.

Claims

1. A process for producing ceramic molds, comprising the steps of:

forming at least one layer of a liquid suspension or plastic mass which includes a ceramic material;

drying the at least one layer;

sintering by laser beam the at least one layer at selected areas; and

repeating the forming, drying and sintering steps more than one time, with each successive layer being positioned on top of a preceding layer to form a mold.

2. A process according to claim 1, wherein the density of the mold has a porosity of less than 40%.

3. A process according to claim 2, wherein the layers have a thickness of 10 to 200 μ

m.

4. A process according to claim 1, wherein th energy input for sintering is set by coordinating a laser power, a laser focus, and a path speed of the laser focus on the at least one layer.

5. A process according to claim 1, wherein the ceramic material is selected from the group consisting of aluminum oxide (Al₂O₃), porcelain powder, highly pure silicic acid, aluminum nitride (AlN), silicon (Si), and silicon nitride (Si₃N₄).

6. A process according to claim 1, wherein the liquid suspension or plastic mass is applied through a gap in an oblong, hollow doctor blade, and the width of the gap lies in the range from 250 to 2000 μ

m.