US4375384A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for penetrant inspection employing an etchant penetrant
Assignee: Boeing North American Inc
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Filing: 1982-03-08
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Granted: 1983-03-01
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Expires: 2002-03-08
Abstract
Abstract A method for detecting cracks and surface discontinuities in an object which comprises applying to the surface of an object having a ground surface and smeared metal, an etchant penetrant solution capable of removing said smeared metal covering the openings of said cracks, cleaning said surface to remove said excess penetrant solution, and applying to said surface a developer coating containing a fluorescent material, the etchant remaining in the cracks being capable of destroying the fluorescence adjacent the cracks, and viewing the surface under ultraviolet light to reveal indications of cracks showing intensely black against a fluorescent background.
Inventors
- 👤 Orlando G. Molina
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:07
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/91
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
96 words
A method for detecting cracks and surface discontinuities in an object which comprises applying to the surface of an object having a ground surface and smeared metal, an etchant penetrant solution capable of removing said smeared metal from adjacent the openings of said cracks, cleaning said surface to remove the excess etchant penetrant, and applying to said surface a developer coating containing a fluorescent material, the etchant remaining in the cracks being capable of destroying the fluorescence adjacent the cracks, and viewing the surface under ultraviolet light to reveal black crack indications against a fluorescent background.
Claim 2
Independent Claim
96 words
A method for detecting cracks and surface discontinuities in an object which comprises applying to the surface of an object having a ground surface and smeared metal, an etchant penetrant solution capable of removing said smeared metal from adjacent the openings of said cracks, cleaning said surface to remove the excess etchant penetrant, and applying to said surface a developer coating containing a fluorescent material, the etchant remaining in the cracks being capable of destroying the fluorescence adjacent the cracks, and viewing the surface under ultraviolet light to reveal black crack indications against a fluorescent background.
Claim 3
Dependent Claim
13 words
The method of claim 1, said etchant penetrant solution being an acid etchant.
Claim 4
Dependent Claim
15 words
The method as defined in claim 1, said etchant penetrant solution being a basic etchant.
Claim 5
Dependent Claim
26 words
The method as defined in claim 1, said developer coating comprising a non-aqueous reversal developer containing an organic solvent, a developer powder and a fluorescent dye.
Claim 6
Dependent Claim
24 words
The method as defined in claim 1, said metal being selected from the group consisting of aluminum, steel, titanium and nickel, and their alloys.
Claim 7
Dependent Claim
23 words
The method as defined in claim 1, said developer containing a small amount of nonionic surfactant, said surfactant being an oxyalkylated alcohol surfactant.
Claim 8
Dependent Claim
19 words
The method as defined in claim 2, said acid etchant comprising a mixture of hydrogen peroxide and hydrochloric acid.
Claim 9
Dependent Claim
18 words
The method as defined in claim 3, said basic etchant comprising a mixture of alkali and chromic acid.
Claim 10
Independent Claim
75 words
A method for detecting cracks and surface discontinuities in an object which comprises applying to the surface of an object an etchant penetrant solution, cleaning said surface to remove excess penetrant, and applying to said surface a developer coating containing a fluorescent material, the etchant remaining in the cracks being capable of destroying the fluorescence adjacent to the cracks, and viewing the surface under ultraviolet light to reveal black crack indications against a fluorescent background.
Claim 11
Independent Claim
75 words
A method for detecting cracks and surface discontinuities in an object which comprises applying to the surface of an object an etchant penetrant solution, cleaning said surface to remove excess penetrant, and applying to said surface a developer coating containing a fluorescent material, the etchant remaining in the cracks being capable of destroying the fluorescence adjacent to the cracks, and viewing the surface under ultraviolet light to reveal black crack indications against a fluorescent background.
Claim 12
Dependent Claim
41 words
The method as defined in claim 6, wherein said surfactant consists of ethoxylates of a mixture of alcohols having the formula: ##STR2## where n is in the range from 9 to 13 and m is an average of 3 to 12.
Claim 13
Dependent Claim
18 words
The method as defined in claim 4, said organic solvent being an oliphatic alcohol or a chlorinated solvent.
Claim 14
Dependent Claim
13 words
The method of claim 10, said etchant penetrant solution being an acid etchant.
Claim 15
Dependent Claim
15 words
The method as defined in claim 10, said etchant penetrant solution being a basic etchant.
Claim 16
Dependent Claim
25 words
The method as defined in claim 9, said developer coating comprising a non-aqueous reversal developer containing an organic solvent, a powder and a fluorescent dye.
Claim 17
Dependent Claim
23 words
The method as defined in claim 14, said organic solvent being an oliphatic alcohol or a chlorinated hydrocarbon and said powder being talc.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-02-28 | 1986-08-30 | 1987-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-28 | 1990-08-30 | 1991-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-28 | 1994-08-30 | 1995-03-01 | $7700.00 | Window Closed / Lapsed |