# US 5,700,408 A · Method of producing a ceramic component by sintering

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- Number: US 5,700,408 A
- Document ID: US5700408A
- Status: Granted
- Kind: A
- Application number: 08/523,813
- Filed: 1995-09-05
- Granted: 1997-12-23
- Earliest claimed: 1994-09-07
- Assignees: W.C. Heraeus GmbH
- Inventors: Bernard Serole
- Web page: https://patentgrep.com/patent/US5700408A

## CPC

- C04B 35/64: Burning or sintering processes (C04B33/32 takes precedence {; powder metallurgy B22F})
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE

## Abstract

In order to achieve, proceeding from the known methods of producing a ceramic component by sintering, in which an oxygenous ceramic powder is introduced into a sintering chamber, heated in there, and dense sintered under application of a halogen-containing sintering auxiliary agent, a simple and inexpensive method in which the oxygen stoichiometry of the sintered component can easily be adjusted to a given value, it is proposed to have the sintering auxiliary agent released from a reservoir separated from the green body at a given sintering temperature, the halogen superficially reacting with the ceramic powder separating oxygen, and the separated oxygen or a defined part of the separated oxygen being caught by way of an oxygen getter.

## Claims

### Claim 1

A method of producing a ceramic component by sintering, in which an oxygenous ceramic powder is formed into a green body which is introduced into a sintering chamber, heated in there, and dense sintered under application of a halogen-containing sintering auxiliary agent, characterized in that at a given sintering temperature the sintering auxiliary agent is released from a reservoir arranged separately from the green body, the halogen superficially reacting with the ceramic powder separating oxygen, and that the separated oxygen or a defined part of the separated oxygen is caught by means of an oxygen getter.

### Claim 2 (depends on 1)

A method according to claim 1, characterized in that the reservoir contains a halogenide out of which the halogen is released by thermal decomposition of the halogenide.

### Claim 3 (depends on 1)

A method according to claim 1, characterized in that the reservoir is arranged within the sintering chamber.

### Claim 4 (depends on 1)

A method according to any claims 1, characterized in that the oxygen getter is arranged within the sintering chamber and contains a reduction agent which reacts with the oxygen at sintering temperature forming an oxide.

### Claim 5 (depends on 4)

A method according to claim 4, characterized in that a reduction agent is chosen in which the oxide is present at sintering temperature in a solid state of aggregation.

### Claim 6 (depends on 1)

A method according to claim 1, characterized in that within the sintering chamber and separated from the component there is an oxygenous compound from which oxygen is released at sintering temperature through decomposition of the oxygenous compound.

### Claim 7 (depends on 1)

A method according to claim 1, characterized in that the reservoir contains CrF.sub.3.

### Claim 8 (depends on 1)

A method according to any one of the above claim 1, characterized in that the oxygen getter contains metallic titanium as a reduction agent.

### Claim 9 (depends on 1)

A method according to claim 1, characterized in that a mixed crystal powder or a powder mixture of indium/tin oxide is used as ceramic powder.