Claims
- 1. A method of producing a diamond article comprising:
- depositing a diamond layer by chemical vapor deposition on a surface of a thermally stable substrate consisting of a tube open at both ends and having an inner surface and an outer surface, said outer surface having a shape substantially the same as that of the desired interior of said diamond article, while supporting said substrate to prevent distortion thereof; and
- submerging said substrate and diamond layer in a vertical position in an etching bath and ultrasonically agitating said etching bath to remove said substrate by etching of the inner surface thereof.
- 2. The method according to claim 1 wherein said substrate is supported by a rod.
- 3. The method according to claim 2 wherein said substrate is molybdenum.
- 4. The method according to claim 1 wherein said substrate is etched by a bath comprising a mixture in equal parts of aqueous hydrochloric acid having a concentration of about 36-38%, aqueous nitric acid having a concentration of about 69-71% by weight and aqueous hydrofluoric acid having a concentration of about 49-51%, all percentages being by weight.
- 5. A method of producing a diamond tube comprising:
- depositing a diamond layer by chemical vapor deposition on a surface of a hollow tubular molybdenum mandrel open at both ends and having an inner surface and an outer surface, said outer surface having a shape substantially the same as that of the desired interior of said diamond tube;
- supporting said mandrel on a rod passing through said mandrel during deposition of said diamond layer to prevent distortion of said mandrel;
- placing said mandrel having said diamond tube formed thereon in a vertical position in an etching bath comprising a mixture in equal parts of aqueous hydrochloric acid having a concentration of about 36-38%, aqueous nitric acid having a concentration of about 69-71% and aqueous hydrofluoric acid having a concentration of about 49-51%, all parts being by weight; and
- ultrasonically agitating said etching bath to etch away said mandrel along the inner surface thereof and produce said diamond tube.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 07/899,034, filed Jun. 15, 1992, which is a continuation of application Ser. No. 07/783,457, filed Oct. 24, 1991, which in turn is a division of application Ser. No. 07/694,170, filed May 1, 1991, all now abandoned.
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May 1990 |
EPX |
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Divisions (1)
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Number |
Date |
Country |
Parent |
694170 |
May 1991 |
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Continuations (2)
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Number |
Date |
Country |
Parent |
899034 |
Jun 1992 |
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Parent |
783457 |
Oct 1991 |
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