Molded object, heating device and method for producing a molded object

Patent metadata

Field	Value
Publication number	US-9321689-B2
Application number	US-200913057926-A
Country	US
Kind code	B2
Filing date	Jul 24, 2009
Priority date	Aug 7, 2008
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A mold ( 30 ), which has a first region ( 10 ) comprising an electroceramic material and a second region ( 20 ) comprising a structural ceramic material, is provided. A heating device with this mold is also specified. Furthermore, a method for producing a mold is provided.

First claim

The invention claimed is:

1. A mold for heating a medium, comprising:
a first region, which has an electroceramic material with a positive temperature coefficient of an electrical resistance and having a perovskite structure and a Curie temperature, which comprises a range from −30° C. to 340° C.;
a second region, which has a structural ceramic material; and
between the first region and the second region, an interfacial region, in which the electroceramic material and the structural ceramic material are sintered to one another, wherein the first region surrounds the second region in a form-fitting engagement for defining said mold as a hollow mold,
wherein the first region is adapted to be heated by applying a voltage to electrical contact areas of the first region, and
wherein the second region is present between the first region and the medium to be heated.

2. The mold of claim 1 , wherein the electroceramic material has the structure Ba 1-x-y M x D y Ti 1-a-b N a Mn b O 3 , where x=0 to 0.5, y=0 to 0.01, a=0 to 0.01, b=0 to 0.01, M comprises a divalent cation, D comprises a trivalent or tetravalent donor, and N comprises a pentavalent or hexavalent cation.

3. The mold of claim 1 , wherein the electroceramic material has a resistivity at 25° C. which lies in a range from 3 Ωcm to 100,000 Ωcm.

4. The mold of claim 1 , wherein the structural ceramic material comprises an oxide ceramic.

5. The mold of claim 4 , wherein the oxide ceramic is chosen from a group which comprises ZrO 2 , Al 2 O 3 and MgO.

6. The mold of claim 1 , wherein the first region, the second region and the interfacial region have coefficients of thermal expansion that differ from one another by less than 2*10 −6 /K.

7. The mold of claim 1 , wherein the interfacial region inhibits the diffusion of constituents of the electroceramic material and of the structural ceramic material.

Assignees

• Ihle Jan
• Kahr Werner
• Steinberger Bernhard
• Epcos Ag

Inventors

• Ihle Jan
• Kahr Werner
• Steinberger Bernhard

Classifications

• C04B2237/348

  Zirconia, hafnia, zirconates or hafnates · CPC title

• C04B2237/32

  Ceramic · CPC title

• C04B37/001

  directly with other burned ceramic articles · CPC title

• C04B2235/3262

  Manganese oxides, manganates, rhenium oxides or oxide-forming salts thereof, e.g. MnO · CPC title

• C04B2235/77

  Density · CPC title