Claims
- 1. A method of forming a thermocouple protection tube comprising
- providing an elongated ceramic tube having an open front end and an open rear end,
- providing an elongated mandrel having an outside dimension substantially matched to the inside dimension of said open front end and inserting said mandrel into said ceramic tube so that a portion of said mandrel extends forward of said open front end,
- depositing a layer of silicon carbide on at least a forward portion of said ceramic tube and said forward-extending portion of said mandrel, and
- removing said mandrel.
- 2. A method according to claim 1 including masking a portion of said ceramic tube in a region adjacent said rear end, whereby silicon carbide is not deposited on said masked portion.
- 3. A method according to claim 1 wherein said silicon carbide is deposited by chemical vapor deposition.
- 4. A method according to claim 1 wherein said mandrel is formed of graphite and where said mandrel is removed by burning of the same.
- 5. A method according to claim 1 wherein said mandrel is formed of a ceramic material having a coefficient of thermal expansion higher than that of silicon carbide, and it is removed from said deposited layer upon cooling.
- 6. The method in accordance to claim 1 wherein said protection tube is formed, such that said portion of said mandrel extending forward of said open front end has an exterior of circular cross-section of uniform diameter and at least a portion of said ceramic tube has a circular cross-section of diameter greater than said uniform diameter.
Parent Case Info
This is a divisional of co-pending application Ser. No. 08/421,177 filed on Apr. 13, 1995.
US Referenced Citations (5)
Divisions (1)
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Number |
Date |
Country |
Parent |
421177 |
Apr 1995 |
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