US2851338A - Method for testing coatings - Google Patents
Method for testing coatings Download PDFInfo
- Publication number
- US2851338A US2851338A US533669A US53366944A US2851338A US 2851338 A US2851338 A US 2851338A US 533669 A US533669 A US 533669A US 53366944 A US53366944 A US 53366944A US 2851338 A US2851338 A US 2851338A
- Authority
- US
- United States
- Prior art keywords
- base
- uranium
- coating
- metal
- gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C17/00—Monitoring; Testing ; Maintaining
- G21C17/06—Devices or arrangements for monitoring or testing fuel or fuel elements outside the reactor core, e.g. for burn-up, for contamination
- G21C17/07—Leak testing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M3/00—Investigating fluid-tightness of structures
- G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
- G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
- G01M3/20—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material
- G01M3/202—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material using mass spectrometer detection systems
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/91—Investigating the presence of flaws or contamination using penetration of dyes, e.g. fluorescent ink
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- General Health & Medical Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Health & Medical Sciences (AREA)
- Plasma & Fusion (AREA)
- General Engineering & Computer Science (AREA)
- High Energy & Nuclear Physics (AREA)
- Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)
Description
States ate t ice NIETHOD FOR TESTING COATINGS Iral B. Johns, Santa Fe, N. Mex., and Amos S. Newton, Ames, Iowa, assignors to the United States of America as represented by the United States Atomic Energy Commission No Drawing. Application May 1, 1944 Serial No. 533,669
4 Claims. (Cl. 23-230) Our invention relates to a method for testing a coating ,on a base material for the presence of small pinholes, cracks, and other nonhomogeneities and discontinuities such as small uncoated portions of the coating not generally discernible on visual inspection.
In the past, various schemes have been devised for testing a coating on a base material, such as a metal base, for the presence of minute uncoated areas but such methods, while changing the appearance of the uncoated areas, have been found unsatisfactory for the purpose of our invention since minute pinholes and the like generally escape notice when under Visual observation, or since the prior schemes are of limited application in other respects.
An object of our invention is to provide a method for testing a coating on a base that will reveal to the naked eye even minute pinholes and the like.
A more specific object of our invention is to provide a method of magnifying the pinholes in a coating of a base material and other minute uncoated areas of the base so that said pinholes and other uncoated areas will be readily discernible upon inspection.
Other objects and advantages will appear from a study of the following description.
It is often found desirable to coat a base, such as, for example, a metal or alloy base with a coating, such as, for example, a metal or alloy coating to protect the base from chemical reactions with the surroundings. As a specific example, when uranium metal is coated with a thin layer of aluminum, zinc, iron, nickel or other metal, or combinations thereof when direct coating is not possible, such layers are liable to have small cracks or holes which are not readily seen in inspection and that may have serious consequences in later use of the coated uranium. For instance, such coated uranium pieces may be used as fissionable elements in a combination with a moderator, such as, for example, a deuterium oxide (i. e. heavy water) moderator, in a nuclear chain reacting system. Any small uncoated areas of uranium would provide small openings through which highly radioactive fission fragments can emanate from the uranium when bombarded by neutrons slowed down by the moderator to thermal energies, that is, energies in thermal equilibrium with the surrounding atmosphere, such fragments contaminating the heavy water moderator, making it very radioactive. Deposition of such fragments will make apparatus, which it contacts, such as pumps, reservoirs and the like, also so radioactive as to require extensive shielding.
In accordance with our invention, a preferred method for testing such coatings for the presence of small pinholes and minute uncoated areas comprises exposing the coated uranium to an atmosphere of a reactive gas which is permanent or relatively non-condensable, such as, for example, hydrogen. In this preferred embodiment the hydrogen is heated to a temperature of approximately 200 to 300 C., to produce a rapid reaction with the material of the uncoated base. If a hole or crack is 2 present, for example, in an aluminum coating or uranium, a chemical reaction occurs between the exposed uranium and hydrogen to form a hydride of uranium, probably UI-I or UH, or a combination of both such compounds. Since such hydride of uranium is afine, light weight black or brownish black powder having about four times the volume of the original metal from which it is formed, the hole or crack is enlargedby pressure of the hydride, and the coating is lifted ,or cracked off. making the flaw larger and easily visible to the human eye. The fact that the compound is of a color easily distinguishable from the coating aids in the visual detection of the presence of the flaw. Hydrogen is also especially desirable because of its ability to diffuse through even microscopic holes mainly because of its small molecular structure. Furthermore, hydrogen does not react with the coating.
Thus it will be seen we have provided an eflicient method for making small pinholes and other small uncoated portions of a coated base readily observable to the human eye.
It will be understood that by permanent or relatively non-condensable gas is meant a gas which does not condense at ordinary room temperatures and under ordinary, e. g. atmospheric, conditions of pressure. It is at present preferred that there be no appreciable condensation of the treating gas to liquid on the surface of the coated object under test, and while this preferred result may be attained by appropriate control of temperatures or pressure, if necessary, the use of gas of relatively noncondensable character appears particularly advantageous, and in such event there is no need for any special control to prevent condensation, at any stage of the testing operation. As also indicated above, a feature of special importance is that the reaction between the gas and the base material (e. g. the reaction with the uranium, constituting either the whole, or as in an alloy, at part of the base material) is preferably such as to produce a relatively voluminous compound that exerts sufficient pressure on the coating to lift or break it away or otherwise to enlarge the hole or crack very appreciably.
While we have disclosed uranium as the base and hydrogen as the reacting gas, it should be noted that the invention is not restricted to the use of these specific elements and that other base metals, such as, for example, plutonium, thorium, zirconium, titanium, hafnium and the like rare metals, or alloys of these metals that react with hydrogen to form a hydride may be used and other gases than hydrogen, such as, for example, ammonia or other volatile hydrogenating agents may be used so long as they form a compound with the base (and not with the coating) that increases appreciably in size as compared to the size of the base portion entering the reaction.
Generally speaking, the gas is so chosen that the free energy change of the reaction between the gas and the base metal at the temperature employed is negative, and the product formed by the reaction of the gas with the base metal has a density lower than that of the base metal. The temperature selected is one at which the gas selected has no marked effect on the coating. We therefore do not wish to limit our invention except insofar as set forth in the following claims.
It is to be understood that unless otherwise stated, references in the claims to a base or a base material or to reaction or reactivity with such base or material, are generically intended to mean not only base materials consisting of a single element, such as uranium, but also base materials including a plurality of elements of which only one (or less than all) may actually enter into chemical reaction with the gas, e. g. as in testing a coating on a uranium metal base consisting of a uranium alloy, where the flaw-detecting gas may not actually react with the supplemental constituents.
We claim:
l. The method of detecting minute uncoated areas .of a metallic uranium base reactive to hydrogen and provided with a difiicultly hydridable coating, comprising applying to the coated surface of the uranium. base a heated atmosphere of gaseous hydrogen at a temperature at which uranium will react with hydrogen to form uranium hydride whereby enlargement of such areas if present will occur.
2. The method of detecting minute uncoated areas of a uranium metal base provided with a diflicultly hydridable coating, comprising applying to the coated surface of the uranium metal base van atmosphere of hydrogen at a temperature of approximately 300 C. to form a hydride of uranium at such uncoated areas whereby enlargement of such areas if present will occur.
3. The method of detecting minute uncoated areas of metallic uranium provided with a difiicultly hydridable coating, comprising exposing the coated surface of the metallic uranium to a hydrogenating gas reactive with the uranium metal at a temperature at which such gas will react with uranium to form uranium hydride whereby enlargement of such areas if present will occur.
4. A method of detecting defects in the coating of a coated article comprising an easily hydridable metal base and a diflicultly hydridable jacket on the base which comprises exposing said coated article to an hydriding agent at a temperature sufiiciently high to form the hydride of said base metal in any pores which may be present .in the coating whereby to effect enlargement of such pores.
References Cited in the file ofthis patent UNITED STATES PATENTS Reinhold Publ. Co., New York (1939), A. C. S. Monograph Series No. 79, page 253.
Claims (1)
- 4. A METHOD OF DETECTING DEFECTS IN THE COATING OF A COATED ARTICLE COMPRISING AN EASILY HYDRIDABLE METAL BASE AND A DIFFICULTY HYDRIDABLE JACKET ON THE BASE WHICH COMPRISES EXPOSING SAID COATED ARTICLE TO AN HYDRIDING AGENT AT A TEMPERATURE SUFFICIENTLY HIGH TO FORM THE HYDRIDE OF SAID BASE METAL IN ANY PORES WHICH MAY BE PRESENT IN THE COATING WHEREBY TO EFFECT ENLARGEMENT OF SUCH PORES.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US533669A US2851338A (en) | 1944-05-01 | 1944-05-01 | Method for testing coatings |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US533669A US2851338A (en) | 1944-05-01 | 1944-05-01 | Method for testing coatings |
Publications (1)
Publication Number | Publication Date |
---|---|
US2851338A true US2851338A (en) | 1958-09-09 |
Family
ID=24126957
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US533669A Expired - Lifetime US2851338A (en) | 1944-05-01 | 1944-05-01 | Method for testing coatings |
Country Status (1)
Country | Link |
---|---|
US (1) | US2851338A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4227081A (en) * | 1979-06-13 | 1980-10-07 | The United States Of America As Represented By The United States Department Of Energy | Method of evaluating the integrity of the outer carbon layer of triso-coated reactor fuel particles |
US4591478A (en) * | 1983-08-26 | 1986-05-27 | The United States Of America As Represented By The Department Of Energy | Method of identifying defective particle coatings |
US5062119A (en) * | 1990-02-02 | 1991-10-29 | Japan Atomic Energy Research Institute | Detection of broken coated fuel particles in ceramic coating layer |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1816830A (en) * | 1929-11-25 | 1931-08-04 | Westinghouse Lamp Co | Preparation of metal hydrides |
US1835024A (en) * | 1929-11-25 | 1931-12-08 | Westinghouse Lamp Co | Preparation of metal hydrides |
-
1944
- 1944-05-01 US US533669A patent/US2851338A/en not_active Expired - Lifetime
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1816830A (en) * | 1929-11-25 | 1931-08-04 | Westinghouse Lamp Co | Preparation of metal hydrides |
US1835024A (en) * | 1929-11-25 | 1931-12-08 | Westinghouse Lamp Co | Preparation of metal hydrides |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4227081A (en) * | 1979-06-13 | 1980-10-07 | The United States Of America As Represented By The United States Department Of Energy | Method of evaluating the integrity of the outer carbon layer of triso-coated reactor fuel particles |
US4591478A (en) * | 1983-08-26 | 1986-05-27 | The United States Of America As Represented By The Department Of Energy | Method of identifying defective particle coatings |
US5062119A (en) * | 1990-02-02 | 1991-10-29 | Japan Atomic Energy Research Institute | Detection of broken coated fuel particles in ceramic coating layer |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Wang et al. | Behavior of plasma sprayed Cr coatings and FeCrAl coatings on Zr fuel cladding under loss-of-coolant accident conditions | |
Yardley et al. | An investigation of the oxidation behaviour of zirconium alloys using isotopic tracers and high resolution SIMS | |
Tupin et al. | Hydrogen diffusion process in the oxides formed on zirconium alloys during corrosion in pressurized water reactor conditions | |
Dali et al. | Corrosion kinetics under high pressure of steam of pure zirconium and zirconium alloys followed by in situ thermogravimetry | |
Alimov et al. | Surface modification and deuterium retention in reduced activation ferritic martensitic steels exposed to low-energy, high flux D plasma and D2 gas | |
Bunn et al. | A high-throughput investigation of Fe–Cr–Al as a novel high-temperature coating for nuclear cladding materials | |
Jones et al. | Evidence of hydrogen trapping at second phase particles in zirconium alloys | |
Tazhibayeva et al. | Study of properties of tungsten irradiated in hydrogen atmosphere | |
Nagase et al. | Performance degradation of candidate accident-tolerant cladding under corrosive environment | |
US2851338A (en) | Method for testing coatings | |
Qu et al. | FeCrAl fuel/clad chemical interaction in light water reactor environments | |
Wierschke | Evaluation of aluminum-boron carbide neutron absorbing materials for interim storage of used nuclear fuel | |
Kim et al. | Characterization of eutectic reaction of Cr and Cr/CrN coated zircaloy accident tolerant fuel cladding | |
Shukla et al. | Evaluation of plasma sprayed sacrificial thermal barrier coatings for core catcher of future sodium cooled fast reactors | |
Lagoyannis et al. | Surface composition and structure of divertor tiles following the JET tokamak operation with the ITER-like wall | |
Billot et al. | Experimental and theoretical studies of parameters that influence corrosion of Zircaloy-4 | |
Liu et al. | Solid tritium breeder materials-Li2O and LiAlO2: A data base review | |
Xu et al. | Effects of double-layer tungsten coatings on hydrogen isotopes plasma-driven and gas-driven permeation through F82H | |
Duan et al. | Corrosion behavior of Pb-39Mg-10Al-1.5 B alloy in sodium halide solutions | |
Lin et al. | Microstructural understanding of general and localized corrosion of Fe13Cr4Al2Mo1. 2Nb alloy in high temperature aerated water and superheated steam | |
Yu et al. | Improved oxidation and hot corrosion resistance of Ta‐doped NiAlY alloy at 750 C | |
Li et al. | High-temperature oxidation and hot corrosion behavior of the Cr-modified aluminide coating obtained by a Thermal Diffusion process | |
Gilbert et al. | Tritium permeation and related studies on barrier treated 316 stainless steel | |
Kim et al. | Anomalous oxidation behavior in a zirconium beryllium intermetallic compound | |
Nemoto et al. | Investigation of the oxidation behavior of Zircaloy-4 cladding in a mixture of air and steam |