Calcinated or sintered hollow body comprising a spherically curved surface

• US 8,449,811 B2
• Filed: 08/17/2006
• Issued: 05/28/2013
• Est. Priority Date: 08/19/2005
• Status: Expired due to Fees

• Current Assignee: Glatt Systemtechnik GmbH (Martina Nowak)
• Original Assignee: Glatt Systemtechnik GmbH (Martina Nowak)
• Inventors: Kretzschmar, Ralf, Bingel, Gert, Hungerbach, Wolfgang
• Primary Examiner(s): Del Sole, Joseph S
• Assistant Examiner(s): KEMMERLE III, RUSSELL J
• Application Number:
  US12/064,209
• Publication Number:
  US 20080299336A1
• Time in Patent Office: 2,476 Days
• Field of Search: 264/603
• US Class Current: 264/603
• CPC Class Codes: B22F 1/0655 Hollow particles
• CPC Class Codes: B22F 1/18 Non-metallic particles coated with metal
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: C04B 2111/00793 as filters or diaphragms
• CPC Class Codes: C04B 2111/0081 as catalysts or catalyst carriers
• CPC Class Codes: C04B 2111/00836 for medical or dental applications
• CPC Class Codes: C04B 2111/52 Sound-insulating materials
• CPC Class Codes: C04B 35/00 Shaped ceramic products characterised by their composition porous ceramic products C04B38/00; ceramic articles characterised by particular shape, see the relevant classes, e.g. linings for casting ladles, tundishes, cups or the like B22D41/02; ceramic substrates for microelectronic semi-conductors H01L23/15; Ceramics compositions containing free metal bonded to carbides, diamond, oxides, borides, nitrides, silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides or sulfides other than as macroscopic reinforcing agents C22C; shaping of ceramics B28B; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products chemical preparation of powders of inorganic compounds C01; infiltration of sintered ceramic preforms with molten metal C04B41/51
• CPC Class Codes: C04B 38/0074 expressed as porosity percentage
• CPC Class Codes: C04B 38/009 Porous or hollow ceramic granular materials, e.g. microballoons C04B18/027, C04B20/002 take precedence
• CPC Class Codes: C04B 38/0615 the burned-out substance being a monolitic element having approximately the same dimensions as the final article, e.g. a porous polyurethane sheet or a prepreg obtained by bonding together resin particles C04B38/0022 takes precedence
• CPC Class Codes: Y10T 428/13 Hollow or container type article [e.g., tube, vase, etc.]

Abstract

A method is for producing calcinated or sintered hollow bodies comprising a spherical surface, to hollow bodies produced using the method, and to the uses thereof. Calcinated or sintered hollow bodies comprising a spherically curved surface, an enlarged, freely accessible surface and/or a structured surface. An organic spherical carrier is coated with a powder which forms the shell of a hollow body, and a binding agent, both contained in suspension. A heat treatment is then carried out, leading to the expulsion of organic constituents and to the sin-tering process. At least one elevation is arranged on the surface of the carrier or embodied thereon, the projection past the surface corresponding at least to the thickness of the shell of the finished sintered hollow body, taking into account the degree of shrinkage of the powder material during the sintering process. The elevation(s) is/are then removed by conversion into the gas phase of the respective material from which they are formed and/or mechanically, during the heat treatment.

Claims

1. A method for manufacture of a calcinated or sintered hollow body, comprising:

coating an organic spherical carrier with a powder, which forms a shell of the hollow body, and a binding agent, the hollow body having a spherically curved surface;

performing one of the following two steps;

(A) forming or arranging at least one elevated portion on a surface of the carrier; and

(B) embedding at least one placeholder into the shell, a vertical projection of the at least one elevated portion or the at least one placeholder corresponds to at least a thickness of the shell of the fully sintered hollow body while taking account of a degree of shrinkage of the powder during sintering; and

heat treating the carrier to remove organic components and sinter,

wherein at least one of the at least one elevated portion and the at least one placeholder is removed by at least one of (a) the heat treatment by conversion into a gas phase of the respective material from which they are made and (b) mechanical removal.

2. The method in accordance with claim 1, wherein when the at least one placeholder is embedded, the at least one placeholder includes one of a placeholder in a particle form and a fibrous placeholder.

3. The method in accordance with claim 1, wherein when the at least one elevated portion is formed, the carrier is coated with a surface structure having elevated portions.

4. The method in accordance with claim 1, wherein when the at least one placeholder is embedded, the at least one placeholder includes at least one of placeholders having different volumes and placeholders having different geometrical design.

5. The method in accordance with claim 1, wherein when the at least one elevated portion is formed, the carrier is coated with at least one of differently dimensioned and designed elevated portions.

6. The method in accordance with claim 1, wherein when the at least one placeholder is embedded, the at least one placeholder is made of one of an organic material and material mixture.

7. The method in accordance with claim 1, wherein the at least one elevated portion is formed or arranged at predetermined positions on the surface of the carrier.