Patent US4135030A successfully refreshed from Google Patents.
US4135030A
Expired / Lapsed
US
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Tungsten impregnated casting mold
Assignee: RTX Corp
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Filing: 1977-12-23
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Granted: 1979-01-16
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Expires: 1997-12-23
Abstract
Abstract A method for producing a low reactivity tungsten impregnated ceramic mold for casting refractory metals such as titanium is described. The method involves impregnation of a standard ceramic shell mold with an aqueous solution of tungstic acid and ammonium hydroxide. The saturated mold is then dried and fired to convert the tungsten compound to metallic tungsten or tungsten oxides. The process may be repeated several times to achieve the desired tungsten concentration.
Inventors
- 👤 Malcolm Basche, deceased
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:30
CPC Classifications
B; B22; B22C; B22C9/00; B22C9/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
55 words
Method for producing a low reactivity tungsten impregnated ceramic mold including the steps of: a. providing a porous ceramic mold; b. providing an aqueous solution containing tungstic acid; c. saturating the mold in the tungstic acid solution; d. drying the mold; e. firing the mold to convert the tungsten acid to tungsten or tungsten oxide.
Claim 2
Dependent Claim
55 words
Method for producing a low reactivity tungsten impregnated ceramic mold including the steps of: a. providing a porous ceramic mold; b. providing an aqueous solution containing tungstic acid; c. saturating the mold in the tungstic acid solution; d. drying the mold; e. firing the mold to convert the tungsten acid to tungsten or tungsten oxide.
Claim 3
Dependent Claim
14 words
A method as in claim 1 wherein steps c, d, and e are repeated.
Claim 4
Dependent Claim
16 words
A method as in claim 1 wherein the aqueous solution contains ammonium hydroxide and tungstic acid.
Claim 5
Dependent Claim
18 words
A method as in claim 1 wherein the aqueous solution is prepared by dissolving ammonium tungstate in water.
Claim 6
Dependent Claim
50 words
A tungsten impregnated ceramic mold useful for casting reactive metals consisting of: a porous ceramic mold whose internal pores and passages are coated with a thin layer of a material selected from the group consisting of metallic tungsten, tungsten oxide, tungsten suboxides, and mixtures thereof, said mold being electrically conductive.
Claim 7
Dependent Claim
50 words
A tungsten impregnated ceramic mold useful for casting reactive metals consisting of: a porous ceramic mold whose internal pores and passages are coated with a thin layer of a material selected from the group consisting of metallic tungsten, tungsten oxide, tungsten suboxides, and mixtures thereof, said mold being electrically conductive.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-01-15 | 1982-07-17 | 1983-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-15 | 1986-07-17 | 1987-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-15 | 1990-07-17 | 1991-01-16 | $7700.00 | Window Closed / Lapsed |