US3484278A - Pyrolytic beryllia - Google Patents
Pyrolytic beryllia Download PDFInfo
- Publication number
- US3484278A US3484278A US493836A US3484278DA US3484278A US 3484278 A US3484278 A US 3484278A US 493836 A US493836 A US 493836A US 3484278D A US3484278D A US 3484278DA US 3484278 A US3484278 A US 3484278A
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- US
- United States
- Prior art keywords
- beryllia
- substrate
- pyrolytic
- deposition
- beryllium
- 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
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- LTPBRCUWZOMYOC-UHFFFAOYSA-N Beryllium oxide Chemical compound O=[Be] LTPBRCUWZOMYOC-UHFFFAOYSA-N 0.000 title description 52
- 238000000034 method Methods 0.000 description 18
- 239000000758 substrate Substances 0.000 description 16
- 238000000151 deposition Methods 0.000 description 12
- ATBAMAFKBVZNFJ-UHFFFAOYSA-N beryllium atom Chemical compound [Be] ATBAMAFKBVZNFJ-UHFFFAOYSA-N 0.000 description 9
- 230000008021 deposition Effects 0.000 description 9
- 229910052790 beryllium Inorganic materials 0.000 description 8
- BDAGIHXWWSANSR-UHFFFAOYSA-M Formate Chemical compound [O-]C=O BDAGIHXWWSANSR-UHFFFAOYSA-M 0.000 description 7
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 230000008016 vaporization Effects 0.000 description 4
- 239000000919 ceramic Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 238000000354 decomposition reaction Methods 0.000 description 3
- -1 ethyl silicate) Chemical compound 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 230000007062 hydrolysis Effects 0.000 description 2
- 238000006460 hydrolysis reaction Methods 0.000 description 2
- 229910001507 metal halide Inorganic materials 0.000 description 2
- 150000005309 metal halides Chemical class 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000000197 pyrolysis Methods 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- 240000000233 Melia azedarach Species 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 241000699670 Mus sp. Species 0.000 description 1
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 1
- 229910001423 beryllium ion Inorganic materials 0.000 description 1
- PWOSZCQLSAMRQW-UHFFFAOYSA-N beryllium(2+) Chemical compound [Be+2] PWOSZCQLSAMRQW-UHFFFAOYSA-N 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000001427 coherent effect Effects 0.000 description 1
- 235000014113 dietary fatty acids Nutrition 0.000 description 1
- 229930195729 fatty acid Natural products 0.000 description 1
- 239000000194 fatty acid Substances 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- 239000007888 film coating Substances 0.000 description 1
- 238000009501 film coating Methods 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 230000002101 lytic effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052755 nonmetal Inorganic materials 0.000 description 1
- 150000002843 nonmetals Chemical class 0.000 description 1
- NJPPVKZQTLUDBO-UHFFFAOYSA-N novaluron Chemical compound C1=C(Cl)C(OC(F)(F)C(OC(F)(F)F)F)=CC=C1NC(=O)NC(=O)C1=C(F)C=CC=C1F NJPPVKZQTLUDBO-UHFFFAOYSA-N 0.000 description 1
- 150000002902 organometallic compounds Chemical class 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- WQGWDDDVZFFDIG-UHFFFAOYSA-N pyrogallol Chemical compound OC1=CC=CC(O)=C1O WQGWDDDVZFFDIG-UHFFFAOYSA-N 0.000 description 1
- 239000003870 refractory metal Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
- C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
- C23C16/30—Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
- C23C16/40—Oxides
- C23C16/403—Oxides of aluminium, magnesium or beryllium
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F3/00—Compounds of beryllium
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C24/00—Coating starting from inorganic powder
Definitions
- BeO is deposited by vaporizing the basic formate of beryllium, heating the vapors to a temperature above their decomposition temperature in a region containing a surface heated to Z50-600 C. whereupon dense BeO is deposited on the surface.
- This invention relates to a process of preparing beryllia by the pyro'lytic process and to the pyrolytic beryllia so produced.
- Among the objects of the invention is to provide a process of preparing hard, dense and thick beryllia deposits.
- Among other objects of the invention is to provide a relatively low temperature process for depositing hard, dense beryllia on a substrate.
- Processes for depositing metal oxides by chemical vapor pyrolysis processes are known and may be classed generally into one of the following categories.
- This invention is based on the discovery that thick, dense, hard, deposits of beryllia can be obtained by the pyrolysis of an organic adduct of beryllium at a relatively low temperature of 300-600 C.
- the deposits can be obtained of any desired thickness.
- the quality of the deposit is improved over deposits obtained at 1000 C., for example, because the total stress developed during deposition is less at the lower temperatures.
- An organic adduct of beryllium may be defined as a compound in which the beryllium ion and the organic radical are held together by means of metal to oxygen to carbon bond, thus differing from organo-metallic compounds in which a metal to carbon bond exists.
- a satisfactory organic adduct is the basic formate, Be40 (HCOzle- A process 'for making the basic organic adducts of beryllium (glucinium) with formic and other fatty acids is disclosed in Comptes Rendu Vo. 134,772 (1902).
- the process of the invention is particularly useful for providing BeO film coatings for the oxidation protection of metals, particularly the refractive metals such as tungsten and molybdenum and for the oxidation protection of certain non-metals such as plastics, carbon (graphite), etc.
- the process is also useful for the production of lightweight impervious structures having a core of foamed or porous material and a coating of the dense pyrolytic BeO. Continuous refractory filaments may be prepared with a core of boron or nickel and a coating of BeO by this process.
- the process also has ⁇ applications in the production of complex shapes by selectively depositing the BeO over unmasked portions of a masked substrate.
- the substrate on which the deposit is 4formed can be any material capable of withstanding temperatures of about 250 or more and can be of any shape.
- Coherent deposits are formed on a substrate of beryllia or other ceramic oxide as well as on the surfaces of refractory metals, plastics, etc.
- the basic formate of beryllia is volatilized (sublimated) and is brought into contact with a preheated substrate in a closed chamber at sub-atmospheric, atmospheric or superatmospheric pressure.
- the substrate to be coated is heated to about 250600 C. or even more if desired.
- One or both of the substrate and the vapor should be heated to the decomposition temperature of the vapor at the surface where the BeO is to be deposited which is between about 30G-600 depending somewhat on the pressure. Lower rates of deposition are obtained at the lower temperatures.
- FIG. l shows an apparatus suitable for the deposition of beryllia by the process of the invention.
- FIG. 2 is a photomicrograph (133 of a cross-section of a deposit of beryllia on a ceramic beryllia substrate made according to the process.
- FIG. 1 shows a bell jar 10 fitted on a suitable base 11 which is provided with a suitable pipe connection 12 for exhausting the -bell jar 10.
- a ceramic pedestal 13 is provided to hold a beryllia plate 14 which in turn is provided with a heater means 1S connected to the outside through leads 16.
- a vaporizing chamber 17 for the organic adduct of beryllium is positioned on the heater 15 and beryllia plate 14.
- the vaporizing chamber 17 is provided with openings permitting the vapor to escape into the chamber means 20 which is adapted to surround a substrate to-be-coated 21.
- Heating means 22 for the substrate having leads 23 through the base 11 are provided.
- Thermocouples 24 and 25 to the vaporizing chamber 17 and deposition chamber respectively are provided.
- EXAMPLE l The apparatus as shown in FIG. 1 is employed with the basic formate of beryllium added to vessel 17 and with a slab of ceramically sintered beryllia as the substrate 21.
- the basic formate compound. sublimes at 185 C. but in this case the bell jar is exhausted to a pressure of 30-35 mm. of Hg whereupon the basic formate begins to sublime at about C.
- the Be() substrate 21 is heated to about 400 C. by heater 22. After about l0 minutes during which the basic formate compound is heated to 200 C., a deposit of BeO approximately 25 mm. in thickness is retained on the substrate.
- the deposit is similar to that shown in FIG. 2, the White portion being the deposit and the lower darker portion being the original substrate. It will be noted that there is a substantially complete absence of pores in the deposited Be() whereas the sintered substrate shows its porous structure.
- Beryllia can be deposited on metal or other surfaces in the same way.
- the substrate is graphite or other form of carbon it is preferred to initiate the process in an inert atmosphere.
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Chemical Vapour Deposition (AREA)
Description
United States Patent O U.S. Cl. 117-106 1 Claim ABSTRACT F THE DISCLOSURE According to the invention BeO is deposited by vaporizing the basic formate of beryllium, heating the vapors to a temperature above their decomposition temperature in a region containing a surface heated to Z50-600 C. whereupon dense BeO is deposited on the surface.
This invention relates to a process of preparing beryllia by the pyro'lytic process and to the pyrolytic beryllia so produced.
Among the objects of the invention is to provide a process of preparing hard, dense and thick beryllia deposits.
Among other objects of the invention is to provide a relatively low temperature process for depositing hard, dense beryllia on a substrate.
Among still other objects of the invention is to provide an improved process for the production of pyrolytic beryllia.
Processes for depositing metal oxides by chemical vapor pyrolysis processes are known and may be classed generally into one of the following categories.
(1) Deposition by steam hydrolysis of certain metal halides.
(2) Deposition by oxidation of a metal halide with oxygen.
(3) Deposition by thermal degradation of a volatile metal compound containing chemically bonded oxygen.
The recommended deposition temperatures for the above reactions are quite high. Thus, Powell et al. in Vapor Plating, John Wiley & Sons (New York 1955), recommend temperatures of the order of 1000 C. for preparing oxide coatings by the steam hydrolysis ofthe halides. Again, Schlossberger et al. in WADC Technical Report 59-363, Research on Pyrolytic Deposition of Thin Films, recommend a temperature for the preparation of oxide tilms by thermal degradation of compounds containing oxygen (such as ethyl silicate), of l200 C. Others dealing with these processes have generally noted that temperatures of approximately 1000 C. or above are required `for the preparation of even thin films.
This invention is based on the discovery that thick, dense, hard, deposits of beryllia can be obtained by the pyrolysis of an organic adduct of beryllium at a relatively low temperature of 300-600 C.
The deposits can be obtained of any desired thickness. The quality of the deposit is improved over deposits obtained at 1000 C., for example, because the total stress developed during deposition is less at the lower temperatures.
An organic adduct of beryllium may be defined as a compound in which the beryllium ion and the organic radical are held together by means of metal to oxygen to carbon bond, thus differing from organo-metallic compounds in which a metal to carbon bond exists. A satisfactory organic adduct is the basic formate, Be40 (HCOzle- A process 'for making the basic organic adducts of beryllium (glucinium) with formic and other fatty acids is disclosed in Comptes Rendu Vo. 134,772 (1902).
Mice
The process of the invention is particularly useful for providing BeO film coatings for the oxidation protection of metals, particularly the refractive metals such as tungsten and molybdenum and for the oxidation protection of certain non-metals such as plastics, carbon (graphite), etc. The process is also useful for the production of lightweight impervious structures having a core of foamed or porous material and a coating of the dense pyrolytic BeO. Continuous refractory filaments may be prepared with a core of boron or nickel and a coating of BeO by this process.
The process also has `applications in the production of complex shapes by selectively depositing the BeO over unmasked portions of a masked substrate.
Thus, the substrate on which the deposit is 4formed can be any material capable of withstanding temperatures of about 250 or more and can be of any shape. Coherent deposits are formed on a substrate of beryllia or other ceramic oxide as well as on the surfaces of refractory metals, plastics, etc.
In the process, the basic formate of beryllia is volatilized (sublimated) and is brought into contact with a preheated substrate in a closed chamber at sub-atmospheric, atmospheric or superatmospheric pressure. The substrate to be coated is heated to about 250600 C. or even more if desired. One or both of the substrate and the vapor should be heated to the decomposition temperature of the vapor at the surface where the BeO is to be deposited which is between about 30G-600 depending somewhat on the pressure. Lower rates of deposition are obtained at the lower temperatures.
=In the drawing:
FIG. l shows an apparatus suitable for the deposition of beryllia by the process of the invention.
FIG. 2 is a photomicrograph (133 of a cross-section of a deposit of beryllia on a ceramic beryllia substrate made according to the process.
The apparatus of FIG. 1 shows a bell jar 10 fitted on a suitable base 11 which is provided with a suitable pipe connection 12 for exhausting the -bell jar 10. A ceramic pedestal 13 is provided to hold a beryllia plate 14 which in turn is provided with a heater means 1S connected to the outside through leads 16. A vaporizing chamber 17 for the organic adduct of beryllium is positioned on the heater 15 and beryllia plate 14. The vaporizing chamber 17 is provided with openings permitting the vapor to escape into the chamber means 20 which is adapted to surround a substrate to-be-coated 21. Heating means 22 for the substrate having leads 23 through the base 11 are provided. Thermocouples 24 and 25 to the vaporizing chamber 17 and deposition chamber respectively are provided.
The following example is given in detail to further illustrate how this invention may be carried out in practice. It is to be understood that the specific details given in the examples are not to be considered as limiting the scope of the invention.
EXAMPLE l The apparatus as shown in FIG. 1 is employed with the basic formate of beryllium added to vessel 17 and with a slab of ceramically sintered beryllia as the substrate 21. The basic formate compound. sublimes at 185 C. but in this case the bell jar is exhausted to a pressure of 30-35 mm. of Hg whereupon the basic formate begins to sublime at about C. The Be() substrate 21 is heated to about 400 C. by heater 22. After about l0 minutes during which the basic formate compound is heated to 200 C., a deposit of BeO approximately 25 mm. in thickness is retained on the substrate. The deposit is similar to that shown in FIG. 2, the White portion being the deposit and the lower darker portion being the original substrate. It will be noted that there is a substantially complete absence of pores in the deposited Be() whereas the sintered substrate shows its porous structure.
Beryllia can be deposited on metal or other surfaces in the same way. When the substrate is graphite or other form of carbon it is preferred to initiate the process in an inert atmosphere.
We claim:
1. The process of forming dense beryllia layers comprising:
providing the basic formate of beryllium,
heating the basic formate of beryllium to form vapors of the same,
4. heating said vapors to a temperature above the decomposition temperature thereof in the region adjacent a surface heated to Z50-600 C. whereby to deposit beryllia on said surface.
References Cited Powell et al., Vapor Deposition, 1966i, pp. 402 and 403 relied upon.
ALFRED L. LEAVI'IT, Primary Examiner A. GO'LIAN, Assistant Examiner
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US49383665A | 1965-10-07 | 1965-10-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3484278A true US3484278A (en) | 1969-12-16 |
Family
ID=23961892
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US493836A Expired - Lifetime US3484278A (en) | 1965-10-07 | 1965-10-07 | Pyrolytic beryllia |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3484278A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3657007A (en) * | 1968-12-03 | 1972-04-18 | Siemens Ag | Method for producing an insulating layer on the surface of a semiconductor crystal |
-
1965
- 1965-10-07 US US493836A patent/US3484278A/en not_active Expired - Lifetime
Non-Patent Citations (1)
| Title |
|---|
| None * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3657007A (en) * | 1968-12-03 | 1972-04-18 | Siemens Ag | Method for producing an insulating layer on the surface of a semiconductor crystal |
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