CA2046335A1 - Forming a metal coating - Google Patents
Forming a metal coatingInfo
- Publication number
- CA2046335A1 CA2046335A1 CA 2046335 CA2046335A CA2046335A1 CA 2046335 A1 CA2046335 A1 CA 2046335A1 CA 2046335 CA2046335 CA 2046335 CA 2046335 A CA2046335 A CA 2046335A CA 2046335 A1 CA2046335 A1 CA 2046335A1
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- CA
- Canada
- Prior art keywords
- metal
- compound
- reagent
- metals
- paint
- 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.)
- Abandoned
Links
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
- C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
- C23C18/02—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition
- C23C18/08—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of metallic material
-
- 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
- C23C16/06—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 metallic material
- C23C16/18—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 metallic material from metallo-organic compounds
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- Chemical & Material Sciences (AREA)
- Metallurgy (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Chemically Coating (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
- Paints Or Removers (AREA)
- Chemical Vapour Deposition (AREA)
Abstract
This invention relates to a method of forming a metal coating on a surface. According to one version of the invention, the method comprises decomposing at the surface a vapour comprising: a first volatile compound between a first metal and a polydentate reagent, and a second volatile compound between a second metal and the same or another polydentate reagent, the reagent(s) being volatile, whereby the metals are co-deposited on the surface. In other versions of the invention, the compounds can be applied to the surface in the liquid phase, in the form of a paint. Such a paint need contain only one metal.
Description
w O 90~08~44 pcT/Gsso~ool6o 2~63~
- 1 :
FORMING A METAL COATING
This lnvention relates to a method of form~ng a single metal or mixed-metals coating on a surface, to a metallic palllt, to a method of paintlng and to a method of spray-forming powders uslng the pa~nt.
05 Metalllc palnts are known whlch comprlse metal (e.g. z1nc or alum~n~ùm) partlcles suspended ln b~nder, plgment and volatlle solvent. Such pa~nts are easy to apply but cannot g~ve a seamless coherent metal coat~ng, wh~ch can be requlred ~n demandlng and advanced technlcal appllcat~ons.
Accordlng to the present lnventlon, a metalllc pa~nt comprlses a compound between the metal or each o~ the ~etals of the palnt and a polydentate reagent, sald compound~s) belng dlssolved ln a palntable solvent.
'' An ob~ect ls palnted, accordlng to the lnventlon~ by apply1ng 15 thereto a palnt as set ~orth above, allowlng the solYent to ?evaporate, and'applyln~ a gaseous or vo~atlle substance whlch can decompose sald compound(s) to release sald metal(s). Metal powder may be made by atomlslng the palnt and applylng a sald gaseous compo~nd.
ZO Accord~ng to another aspect of the 1nventlon, the method of formlng mlxed-metal coatings on a surface comprlses decompos1ng at the surface a flu~d e.g. vapour comprls1ng:
a f1rst preferably volat~le compound between a first metal and a polydentate reagent, and a second preferably volat~le compound between a second metal and the same or another polydentate reagent, wherein the reagent(s) is/are volatile, whereby the metals are co-deposited on the surface. The reagent(s) and the compounds are preferably stable in alr. The decomposltlon preferably y~elds the reagent(s) d~rectly, whlch accordingly may be recovered for re-use.
Transport o~ the 'bulk' complex ~n vapour phase and I
reactlon on the heated substrate can ln certa~n cases result ~n ~ o~ PCT/GB90/00160 2~A6~
lnteractlons between the regenerating ligand and substrate material, i.e. removal of surface oxide, or the formatlon of a volatile intermedlate whlch itself ls reduced later. This would particularly be enhanced where the chelat~ng llgands are o5 e~tremely actlve toward the base material. Thus, ln one optlon, the satd second metal ls the surface and the sald second volat~le compound is formed from reagent llberated upon decomposltlon o~ the flrst volatlle compound. By thls technlque, ~nterpenetratlon of metals can be achleved at lower temperatures than if, say, dlffuslon was belng relled upon.
Preferably the decompositlon of the polydentate reagent(s) to metal ls by reductlon. Preferably the reduction ls performed by a gas or gases.
Preferably the donor atoms o~ the sald reagent~s) are any selectlon from N, O and S. Pre~Qrably the sald reagent (or one o~ sa~d reagents) ls a Schl~f base or a ~-dlketone. Both thes~
are alr~stable and non-tox~c, unllkQ ~or example metal alkyls and metal carbonyls.
Where the reagents ar~ dlfferent ~or the two metals, at least ZO one may comprlse ballastlng substttuents. Thus, by exploltlng the resultlng dlf~erentlal volatllltles o~ the two compounds, thelr relatlve vapour pressures can be varled so as to ad~ust the composlt~on of the resultlng metal mixture 1f other ways of alter1ng the vapour compos1t~on are not avallable.
One of the metals may be copper and the other may be nickel.
The substrate may be a metal or glass or ceramic (e.g. alum1na) or a membrane requiring to be ~etallised.
UK Patent GB 2135984B, the disclosure of which is imported by reference, clalms a method of winning metal from ore, and d1scloses for that purpose compounds wh1ch may f1nd use 1n th1s ~nvent~on, such as, in the case of Cu(II), tetradentate Schlff base reagents.
.
.
., W o 90/08~4~ pcT/GBso/ool6o 2~3~
~ -diketones wh~ch may be used include for example 2,2,6,6 tetramethyl 3,5 heptadione (trivilally called tert-butyl acetyl acetone), two molecules of which complex each copper atom:
05 C ~ / CH3 CH~ C - C ~ C - C - C ~ CH 3 11 ~ 11 \
CH3 0~ ,0 CH3 `'Cu~
The removal of surface ox'ide, mentloned earller, takes place as ~ollows.
Complex ML ~ Decomposlng agent say H2 ~ DeposltQd metal M ~ polydQntatQ reagQnt LH2 Regenerated ~Hz ~ Sur~ac~ oxlde M0 ~ ~120 vapour ~ ML
Note that sur~ace oxlde can be removed at low temperature (e.g. 300C), below the onset of rapid diffus~on. Thls feature lmproves the adheslon of deposlted metal.
The inventlon wlll now be descr~bed by way of example.
The co-deposition of metals, e.g. nickel and copper on varlous substrates, was carrled out using physically mixed 'powdered' proportions of respective metal complexes. A range of `-metallic complex mixtures was prepared by physical m'ixing, and each m1xture was shaken and volatillised prior to reduction and deposltilon. ~he volatilisation temperatures were dependent upon the 'mixtures' used, generally iin the region of 180-200C for ~diketonoate complexes, and around 250C for Schiff's base . 30 complexes. The relative percentage of respective metals iln t ~ ~, ..: \
.
w o s~/oBs44 P ~ /GBso/oo~6 deposlt depends as mentioned on the relative volatlllt~es of the complexes. Thus a mixture of nickel and copper 2,2,6,6-tetramethyl-3,5-heptandioate complexes ~n the proportions Nl 70:Cu 30 gave a deposit containing the same ratio of metals.
05 With a mixture of the same ratio, but 2,4-pentandione as the chelate, a higher proportlon of copper was detected.
In the following examples, deposltlon temperatures of between 350 ~ ~50 ~ lO~C and total gas flow ~carrler and reductant) o~
75 ~ 5 cm3/m1n were used.
Prlor to any deposltlon all substrates were washed ln 0.1 M
HCl, followed by an acetone rinse.
EXAMPLE 1: NiCu alloy ~s deposlted on mlld steel.
A physlcally mlxed composltlon of Nl/Cu ~heptandloate)2 complex mentloned above, ~n the metals ratlo 70:30, was welghed ~n a sample boat and placed ~n a volatlllzatlon zone. ~Total complex 0.4273g; Nl 0.0415g; Cu O.Ol9g). The system was lnltlally ~lush~d wlth nl~rogen. Then hydrogen ~15 ~ 5 cm3/mln) was tntroduced lnto th~ system. The substrate, mounted on a heatlng probe, was brought to a steady state temperature ~400 ~
10C) before the complex mlxture was heated to its volatlli~atlon temperature o~ 180~C and held for a perlod of 1 hr.
Poroslty o~ the resulting NlCu alloy deposlt on the mlld steel substrate was determlned using a chemical stalnlng technique, lncorporat1ng a sens1tlv1ty test for the substrate metal. A p~ece of f~lter paper was d~pped lnto a solution of hexacyanoferrate (III), then- pressed l~ghtly on to the thln depos~t. hlthough a quantit~ve result was not obtained from the test, it gave an indication as to the poroslty of the deposit, in that any holes in the de~os1t resu)ted in a blue stain on the 3V filter paper.
EXAMPLE 2: NiFe alloy is deposited on mlld steel by depositlng Ni and relylng on the freshly liberated ligand to react w~th the substrate 1ron, the lron complex then be~ng decomposed alongside the nlckel complex.
, . ' . ' '' , ' ' ., ' . ' ' :. ~, ', ' , w o 90/0884~ PCT/CB90/00160 20~6335 In this case, the nickel complex used was nlckel bis 1,1,1-trifluoro-2,4-pentanedioate, Ni(tfa)2 for short. Ni(tfa)2, 0.4344 g, was weighed in a sample boat and placed in a volatlzation zone. The system was lnitlally flushed with oS nitrogen. Then hydrogen (10 ~ 5 cm3/min) was introduced into the system. The mlld steel substrate, mounted on a heat~ng probe, was heated to 400 ~ 10C before the complex was vapourlsed over a perlod of 1 hr at a temperature o~ 190C.
Cross-sect~onal analysls of the coated substrate, uslng an energy dispersive X-ray analyser, showed interpenetratton of the base metal (steel) into the coating (nickel). Quantit~ve results have lndlcated the migratlon of lron to the nickel to be as hlgh as 11% ln cases where the coating has been bullt-up durlng a number of separate runs.
EXAMPLES 3 - S: NiCu alloy ls deposited on stllca glass/on alumina/on aluminium.
In each case a thln yet non-porous coh~rcnt and adhcrent ~llm of alloy was achleved, a~ a temperature low enough not to damage the substrate, even wlth substrates havlng awkward grooves and undercuts; that is, the method has good throwing power.
In Example 5 (alumlnlum substrate) ln partlcular, the operat~ng condltlons were ldentlcal to Example 1.
In~tial mlcrohardness measurements of cross-sectional pieces of coated substrate ~mounted in plastlcs) have indicated that the deposlt in some cases is harder than the substrate. However, these results are tentattve where the depos~t ls extremely thin, such as 10 ~m.
EXAMPLE 6: Coating powder particles can radically alter their propert~es. The coatings may only be a few atoms thick - less than 1% of the weight of the powder, yet be effectlve. In this example, metallic copper is deposited on supermagnetic flakes, ` Y,mm x Y,mm x /~omm for example, of iron neodymlum borlde Fel4NdB, known as Magnequench-, or equally successfully on S-mlcr~n Fel4NdB
powder known as B14.
.
w o go/08844 pcT/Gsso/ool6o r~ 3 6 -This copper provides a non-magnetic insulation ; on compressing the flakes (or powder particles), a small-domain highly magnetic material is obtained. This task would be difficult to achleve us~ng conventional metal paint, and is oS conventionally performed by tumbling the flakes with copper powder ln a process known as tumble-co-milling , which cannot yield the same unlformlty of magne~lc lnsulatlon without greater volumetrlc dllut~on of the supermagnet~c matérlal.
A copper complex conslsting of the compound 10 2,Z,6,6~tetramethyl-3,5-heptadlone described above, two molecules of which complex each copper atom, was used.
B14 ls very pyrophor1c and ls therefore stored under cyclohexane. The copper complex ls dissolved dlrectly lnto thls, ~n an amount dependlng on the ~hlckness of copper coatlng lS requlred after calculat~ng the partlcle surface area: for magnetlc purposes the coatlng thlckness should be the mlnlmum whlch wlll survlve compresslon wlthout rupturlng. In thls example, the complex was calculated to amount to 1% ~based on copper) by mass of the B14. The same procedure, uslng cyclohexane, was also used wlth Magnequench. The mlxture was shaken thoroughly at room ~emperature. The solvent cyclohexane was evaporated under nltrogen at 100C before lncreaslng the temperature of the system and chan~ing to a hydrogen atmosphere to deposit the copper on the Fel4NdB at operatlng temperatures of 2S 210C for 1 hour. At much lower temperatures, the complex wtll not give up the copper at an ade~uate speed, while at much higher temperatures, the liberated dione may attack and extract the substrate Fel4NdB.
Good coverage of the Fel4NdB with copper was established by vtsual ~nspectlon, and by noting in the case of B14 that the product was ~ç~ pyrophoric. In some cases lt may be advantageous as a final step to dry tumble the coated mater~al to assist good overall coverage.
. ... ., .,, 1 .
.
. .
; . . ~, ,; ; . ~ .. ..
WO 90/08X4~ PCl/GB90/1)i)160 20~335 The hydrogen gas reduces the complex, yielding elemental solid metal and liberating, in the gas phase, the initial chelating ligand. Inlt~al n.m.r. and i.r. studles on the collected products have shown that whllst a number of ligands can OS be regenerated to some purity , especlally straight cha~n alkane ~-dlketones, their fluorinated derivatives are prone to some decomposltion.
EXAMPIE 7:
In other appl~catlons, the copper complex of Example 6 dlssolved ln cyclohexane or d1ethyl ether was brush palnted onto a substrate, whlch was heated to 210C for 1 hour ~n hydrogen. A
contlnuous copper coatlng was left on the substrate, and the liberated 11gand could be recycled to make further palnt.
EXAMPLE 8:
In another appllcatlon, the copper complex of Example 6 ln solutlon was ~etted, through an atomtslng nozzle, as a ~lne spray tn~o a chambèr con~aln~ng hydrogen a~ 250~C. Copper powder was rQcovered ~rom the chambQr~ Th~ llberated llgand could be recycled. Care must be taken to avold an undue proportlon of the complex from decomposing on the chamber walls and slmply plat~ng them, for example a cyclonlc gas flow path may be establlshed wlth~n the chamber so that the cc~plex does not contact the chamber wall.
A mixture of such compounds may be used, ln the same or separate sprays, to yield a mixture of liberated metals, in precalculated volumetric proportions of liquid to yleld the metals in the desired ratios.
Preferably the metal ~s one or more of a m~xture of copper and n~ckel.
A mlxture of such metal powders may permit alloys to be made by pressure-sintering wh~ch would otherwise be unobtalnable or only obtainable by extraordinary techniques such as 1mplantation by nuclear bombardment.
- 1 :
FORMING A METAL COATING
This lnvention relates to a method of form~ng a single metal or mixed-metals coating on a surface, to a metallic palllt, to a method of paintlng and to a method of spray-forming powders uslng the pa~nt.
05 Metalllc palnts are known whlch comprlse metal (e.g. z1nc or alum~n~ùm) partlcles suspended ln b~nder, plgment and volatlle solvent. Such pa~nts are easy to apply but cannot g~ve a seamless coherent metal coat~ng, wh~ch can be requlred ~n demandlng and advanced technlcal appllcat~ons.
Accordlng to the present lnventlon, a metalllc pa~nt comprlses a compound between the metal or each o~ the ~etals of the palnt and a polydentate reagent, sald compound~s) belng dlssolved ln a palntable solvent.
'' An ob~ect ls palnted, accordlng to the lnventlon~ by apply1ng 15 thereto a palnt as set ~orth above, allowlng the solYent to ?evaporate, and'applyln~ a gaseous or vo~atlle substance whlch can decompose sald compound(s) to release sald metal(s). Metal powder may be made by atomlslng the palnt and applylng a sald gaseous compo~nd.
ZO Accord~ng to another aspect of the 1nventlon, the method of formlng mlxed-metal coatings on a surface comprlses decompos1ng at the surface a flu~d e.g. vapour comprls1ng:
a f1rst preferably volat~le compound between a first metal and a polydentate reagent, and a second preferably volat~le compound between a second metal and the same or another polydentate reagent, wherein the reagent(s) is/are volatile, whereby the metals are co-deposited on the surface. The reagent(s) and the compounds are preferably stable in alr. The decomposltlon preferably y~elds the reagent(s) d~rectly, whlch accordingly may be recovered for re-use.
Transport o~ the 'bulk' complex ~n vapour phase and I
reactlon on the heated substrate can ln certa~n cases result ~n ~ o~ PCT/GB90/00160 2~A6~
lnteractlons between the regenerating ligand and substrate material, i.e. removal of surface oxide, or the formatlon of a volatile intermedlate whlch itself ls reduced later. This would particularly be enhanced where the chelat~ng llgands are o5 e~tremely actlve toward the base material. Thus, ln one optlon, the satd second metal ls the surface and the sald second volat~le compound is formed from reagent llberated upon decomposltlon o~ the flrst volatlle compound. By thls technlque, ~nterpenetratlon of metals can be achleved at lower temperatures than if, say, dlffuslon was belng relled upon.
Preferably the decompositlon of the polydentate reagent(s) to metal ls by reductlon. Preferably the reduction ls performed by a gas or gases.
Preferably the donor atoms o~ the sald reagent~s) are any selectlon from N, O and S. Pre~Qrably the sald reagent (or one o~ sa~d reagents) ls a Schl~f base or a ~-dlketone. Both thes~
are alr~stable and non-tox~c, unllkQ ~or example metal alkyls and metal carbonyls.
Where the reagents ar~ dlfferent ~or the two metals, at least ZO one may comprlse ballastlng substttuents. Thus, by exploltlng the resultlng dlf~erentlal volatllltles o~ the two compounds, thelr relatlve vapour pressures can be varled so as to ad~ust the composlt~on of the resultlng metal mixture 1f other ways of alter1ng the vapour compos1t~on are not avallable.
One of the metals may be copper and the other may be nickel.
The substrate may be a metal or glass or ceramic (e.g. alum1na) or a membrane requiring to be ~etallised.
UK Patent GB 2135984B, the disclosure of which is imported by reference, clalms a method of winning metal from ore, and d1scloses for that purpose compounds wh1ch may f1nd use 1n th1s ~nvent~on, such as, in the case of Cu(II), tetradentate Schlff base reagents.
.
.
., W o 90/08~4~ pcT/GBso/ool6o 2~3~
~ -diketones wh~ch may be used include for example 2,2,6,6 tetramethyl 3,5 heptadione (trivilally called tert-butyl acetyl acetone), two molecules of which complex each copper atom:
05 C ~ / CH3 CH~ C - C ~ C - C - C ~ CH 3 11 ~ 11 \
CH3 0~ ,0 CH3 `'Cu~
The removal of surface ox'ide, mentloned earller, takes place as ~ollows.
Complex ML ~ Decomposlng agent say H2 ~ DeposltQd metal M ~ polydQntatQ reagQnt LH2 Regenerated ~Hz ~ Sur~ac~ oxlde M0 ~ ~120 vapour ~ ML
Note that sur~ace oxlde can be removed at low temperature (e.g. 300C), below the onset of rapid diffus~on. Thls feature lmproves the adheslon of deposlted metal.
The inventlon wlll now be descr~bed by way of example.
The co-deposition of metals, e.g. nickel and copper on varlous substrates, was carrled out using physically mixed 'powdered' proportions of respective metal complexes. A range of `-metallic complex mixtures was prepared by physical m'ixing, and each m1xture was shaken and volatillised prior to reduction and deposltilon. ~he volatilisation temperatures were dependent upon the 'mixtures' used, generally iin the region of 180-200C for ~diketonoate complexes, and around 250C for Schiff's base . 30 complexes. The relative percentage of respective metals iln t ~ ~, ..: \
.
w o s~/oBs44 P ~ /GBso/oo~6 deposlt depends as mentioned on the relative volatlllt~es of the complexes. Thus a mixture of nickel and copper 2,2,6,6-tetramethyl-3,5-heptandioate complexes ~n the proportions Nl 70:Cu 30 gave a deposit containing the same ratio of metals.
05 With a mixture of the same ratio, but 2,4-pentandione as the chelate, a higher proportlon of copper was detected.
In the following examples, deposltlon temperatures of between 350 ~ ~50 ~ lO~C and total gas flow ~carrler and reductant) o~
75 ~ 5 cm3/m1n were used.
Prlor to any deposltlon all substrates were washed ln 0.1 M
HCl, followed by an acetone rinse.
EXAMPLE 1: NiCu alloy ~s deposlted on mlld steel.
A physlcally mlxed composltlon of Nl/Cu ~heptandloate)2 complex mentloned above, ~n the metals ratlo 70:30, was welghed ~n a sample boat and placed ~n a volatlllzatlon zone. ~Total complex 0.4273g; Nl 0.0415g; Cu O.Ol9g). The system was lnltlally ~lush~d wlth nl~rogen. Then hydrogen ~15 ~ 5 cm3/mln) was tntroduced lnto th~ system. The substrate, mounted on a heatlng probe, was brought to a steady state temperature ~400 ~
10C) before the complex mlxture was heated to its volatlli~atlon temperature o~ 180~C and held for a perlod of 1 hr.
Poroslty o~ the resulting NlCu alloy deposlt on the mlld steel substrate was determlned using a chemical stalnlng technique, lncorporat1ng a sens1tlv1ty test for the substrate metal. A p~ece of f~lter paper was d~pped lnto a solution of hexacyanoferrate (III), then- pressed l~ghtly on to the thln depos~t. hlthough a quantit~ve result was not obtained from the test, it gave an indication as to the poroslty of the deposit, in that any holes in the de~os1t resu)ted in a blue stain on the 3V filter paper.
EXAMPLE 2: NiFe alloy is deposited on mlld steel by depositlng Ni and relylng on the freshly liberated ligand to react w~th the substrate 1ron, the lron complex then be~ng decomposed alongside the nlckel complex.
, . ' . ' '' , ' ' ., ' . ' ' :. ~, ', ' , w o 90/0884~ PCT/CB90/00160 20~6335 In this case, the nickel complex used was nlckel bis 1,1,1-trifluoro-2,4-pentanedioate, Ni(tfa)2 for short. Ni(tfa)2, 0.4344 g, was weighed in a sample boat and placed in a volatlzation zone. The system was lnitlally flushed with oS nitrogen. Then hydrogen (10 ~ 5 cm3/min) was introduced into the system. The mlld steel substrate, mounted on a heat~ng probe, was heated to 400 ~ 10C before the complex was vapourlsed over a perlod of 1 hr at a temperature o~ 190C.
Cross-sect~onal analysls of the coated substrate, uslng an energy dispersive X-ray analyser, showed interpenetratton of the base metal (steel) into the coating (nickel). Quantit~ve results have lndlcated the migratlon of lron to the nickel to be as hlgh as 11% ln cases where the coating has been bullt-up durlng a number of separate runs.
EXAMPLES 3 - S: NiCu alloy ls deposited on stllca glass/on alumina/on aluminium.
In each case a thln yet non-porous coh~rcnt and adhcrent ~llm of alloy was achleved, a~ a temperature low enough not to damage the substrate, even wlth substrates havlng awkward grooves and undercuts; that is, the method has good throwing power.
In Example 5 (alumlnlum substrate) ln partlcular, the operat~ng condltlons were ldentlcal to Example 1.
In~tial mlcrohardness measurements of cross-sectional pieces of coated substrate ~mounted in plastlcs) have indicated that the deposlt in some cases is harder than the substrate. However, these results are tentattve where the depos~t ls extremely thin, such as 10 ~m.
EXAMPLE 6: Coating powder particles can radically alter their propert~es. The coatings may only be a few atoms thick - less than 1% of the weight of the powder, yet be effectlve. In this example, metallic copper is deposited on supermagnetic flakes, ` Y,mm x Y,mm x /~omm for example, of iron neodymlum borlde Fel4NdB, known as Magnequench-, or equally successfully on S-mlcr~n Fel4NdB
powder known as B14.
.
w o go/08844 pcT/Gsso/ool6o r~ 3 6 -This copper provides a non-magnetic insulation ; on compressing the flakes (or powder particles), a small-domain highly magnetic material is obtained. This task would be difficult to achleve us~ng conventional metal paint, and is oS conventionally performed by tumbling the flakes with copper powder ln a process known as tumble-co-milling , which cannot yield the same unlformlty of magne~lc lnsulatlon without greater volumetrlc dllut~on of the supermagnet~c matérlal.
A copper complex conslsting of the compound 10 2,Z,6,6~tetramethyl-3,5-heptadlone described above, two molecules of which complex each copper atom, was used.
B14 ls very pyrophor1c and ls therefore stored under cyclohexane. The copper complex ls dissolved dlrectly lnto thls, ~n an amount dependlng on the ~hlckness of copper coatlng lS requlred after calculat~ng the partlcle surface area: for magnetlc purposes the coatlng thlckness should be the mlnlmum whlch wlll survlve compresslon wlthout rupturlng. In thls example, the complex was calculated to amount to 1% ~based on copper) by mass of the B14. The same procedure, uslng cyclohexane, was also used wlth Magnequench. The mlxture was shaken thoroughly at room ~emperature. The solvent cyclohexane was evaporated under nltrogen at 100C before lncreaslng the temperature of the system and chan~ing to a hydrogen atmosphere to deposit the copper on the Fel4NdB at operatlng temperatures of 2S 210C for 1 hour. At much lower temperatures, the complex wtll not give up the copper at an ade~uate speed, while at much higher temperatures, the liberated dione may attack and extract the substrate Fel4NdB.
Good coverage of the Fel4NdB with copper was established by vtsual ~nspectlon, and by noting in the case of B14 that the product was ~ç~ pyrophoric. In some cases lt may be advantageous as a final step to dry tumble the coated mater~al to assist good overall coverage.
. ... ., .,, 1 .
.
. .
; . . ~, ,; ; . ~ .. ..
WO 90/08X4~ PCl/GB90/1)i)160 20~335 The hydrogen gas reduces the complex, yielding elemental solid metal and liberating, in the gas phase, the initial chelating ligand. Inlt~al n.m.r. and i.r. studles on the collected products have shown that whllst a number of ligands can OS be regenerated to some purity , especlally straight cha~n alkane ~-dlketones, their fluorinated derivatives are prone to some decomposltion.
EXAMPIE 7:
In other appl~catlons, the copper complex of Example 6 dlssolved ln cyclohexane or d1ethyl ether was brush palnted onto a substrate, whlch was heated to 210C for 1 hour ~n hydrogen. A
contlnuous copper coatlng was left on the substrate, and the liberated 11gand could be recycled to make further palnt.
EXAMPLE 8:
In another appllcatlon, the copper complex of Example 6 ln solutlon was ~etted, through an atomtslng nozzle, as a ~lne spray tn~o a chambèr con~aln~ng hydrogen a~ 250~C. Copper powder was rQcovered ~rom the chambQr~ Th~ llberated llgand could be recycled. Care must be taken to avold an undue proportlon of the complex from decomposing on the chamber walls and slmply plat~ng them, for example a cyclonlc gas flow path may be establlshed wlth~n the chamber so that the cc~plex does not contact the chamber wall.
A mixture of such compounds may be used, ln the same or separate sprays, to yield a mixture of liberated metals, in precalculated volumetric proportions of liquid to yleld the metals in the desired ratios.
Preferably the metal ~s one or more of a m~xture of copper and n~ckel.
A mlxture of such metal powders may permit alloys to be made by pressure-sintering wh~ch would otherwise be unobtalnable or only obtainable by extraordinary techniques such as 1mplantation by nuclear bombardment.
Claims (18)
1. A method of forming a mixed-metals coating on a surface, comprising decomposing at the surface a fluid comprising:
a first compound between a first metal and a polydentate reagent, and a second compound between a second metal and the same or another polydentate reagent, wherein the reagent(s) is/are volatile, whereby the metals are co-deposited on the surface.
a first compound between a first metal and a polydentate reagent, and a second compound between a second metal and the same or another polydentate reagent, wherein the reagent(s) is/are volatile, whereby the metals are co-deposited on the surface.
2. A method according to Claim 1, wherein the said second metal is the surface and wherein the said second compound is formed from reagent liberated upon decomposition of the first compound.
3. A method according to either preceding claim, wherein the decomposition is by reduction.
4. A method according to Claim 3 wherein the reduction is performed by a gas or gases.
5. A method according to any preceding claim, wherein the donor atoms of the said reagent are any selection from N, O and S.
6. A method according to anypreceding claim, wherein the said reagent (or one of said reagents) is a Schiff base reagent or a .beta.-diketone.
7. A method according to any preceding claim, wherein one of the metals is copper.
8. A method according to any preceding claim, wherein one of the metals is nickel.
9. A method according to any preceding claim, wherein said first compound is volatile.
10. A method according to any preceding claim, wherein said second compound is volatile.
11. A method according to any preceding claim, wherein said fluid is a vapour.
12. A method according to any of Claims 1-8, wherein said fluid is a liquid.
13. A method according to any preceding claim, wherein the surface is of metal, glass or ceramic or is a membrane.
14. A metallic paint, comprising a compound between the metal or each of the metals of the paint and a polydentate reagent, said compound(s) being dissolved in a paintable solvent.
15. A paint according to Claim 14, wherein the donor atoms of said reagent(s) are any selection of N, O and S.
16. A method of painting an object, comprising applying thereto a paint according to any preceding claim, allowing the solvent to evaporate, and applying a gaseous or volatile substance which can decompose said compound(s) to release said metal(s).
17. A method of painting according to Claim 16, wherein said compound or at least one of said compounds is dissolved in said solvent after the object has been placed in the solvent.
18. A method of making metal powder, comprising atomising a paint according to Claim 14, and applying a gaseous substance which decomposes said compound(s) to release said metal(s).
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8902310.5 | 1989-02-02 | ||
| GB8902312.1 | 1989-02-02 | ||
| GB898902312A GB8902312D0 (en) | 1989-02-02 | 1989-02-02 | Making metal powder |
| GB8902311.3 | 1989-02-02 | ||
| GB898902311A GB8902311D0 (en) | 1989-02-02 | 1989-02-02 | Metallic paint |
| GB898902310A GB8902310D0 (en) | 1989-02-02 | 1989-02-02 | Forming mixed-metal coating |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2046335A1 true CA2046335A1 (en) | 1990-08-03 |
Family
ID=27264297
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2046335 Abandoned CA2046335A1 (en) | 1989-02-02 | 1990-02-01 | Forming a metal coating |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0456679A1 (en) |
| JP (1) | JPH04503085A (en) |
| CA (1) | CA2046335A1 (en) |
| GB (1) | GB2229453A (en) |
| WO (1) | WO1990008844A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102008029691A1 (en) * | 2008-06-24 | 2009-12-31 | Leibniz-Institut Für Neue Materialien Gemeinnützige Gmbh | Mixtures of precursors for the production of ceramic layers by means of MOCVD |
Family Cites Families (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB872610A (en) * | 1958-03-07 | 1961-07-12 | Union Carbide Corp | Gas plating of aggregates |
| US3092511A (en) * | 1958-11-19 | 1963-06-04 | Sperry Rand Corp | Magnetic devices and preparation thereof |
| US3092510A (en) * | 1959-03-02 | 1963-06-04 | Sperry Rand Corp | Magnetic devices and preparation thereof |
| US3242102A (en) * | 1960-06-30 | 1966-03-22 | Sperry Rand Corp | Metal chelate polymers |
| US3071493A (en) * | 1961-11-15 | 1963-01-01 | Ethyl Corp | Metal plating process |
| NL286046A (en) * | 1961-12-01 | |||
| FR1406882A (en) * | 1963-09-13 | 1965-07-23 | Ass Chem Co | Improvements to surface coating |
| NL6505307A (en) * | 1964-06-25 | 1965-12-27 | ||
| SE306771B (en) * | 1965-09-14 | 1968-12-09 | Asea Ab | |
| GB1109890A (en) * | 1965-12-21 | 1968-04-18 | Int Nickel Ltd | Preparation of finely divided metals |
| GB1249623A (en) * | 1967-05-24 | 1971-10-13 | Secr Defence | Improvements in or relating to metal coatings |
| US3594216A (en) * | 1969-06-19 | 1971-07-20 | Westinghouse Electric Corp | Vapor phase deposition of metal from a metal-organic beta-ketoamine chelate |
| US3615888A (en) * | 1969-09-04 | 1971-10-26 | American Cyanamid Co | Chemical treatment of metal |
| CA935336A (en) * | 1970-05-29 | 1973-10-16 | V. Melnikov Valery | Method of depositing inorganic coatings from vapour phase |
| NL7117454A (en) * | 1970-12-24 | 1972-06-27 | ||
| IT1041860B (en) * | 1974-08-23 | 1980-01-10 | Schladitz J H | PROCEDURE FOR MAKING A HEAT EXCHANGER ELEMENT OR A HEAT TRANSMISSION ELEMENT |
| FR2314263A1 (en) * | 1975-06-13 | 1977-01-07 | Anvar | Vacuum vapour deposition of metals or metalloids - by thermal decomposition of their coordination cpds. with (2,2')-bipyridyl |
| FR2325621A1 (en) * | 1975-09-29 | 1977-04-22 | Engelhard Mineral Chemical Cor | DECORATION FOR CERAMIC MATERIALS WITH A SHINY WHITE METAL APPEARANCE |
| US4250210A (en) * | 1977-12-27 | 1981-02-10 | The International Nickel Co., Inc. | Chemical vapor deposition |
-
1990
- 1990-02-01 EP EP19900902310 patent/EP0456679A1/en not_active Withdrawn
- 1990-02-01 JP JP50238590A patent/JPH04503085A/en active Pending
- 1990-02-01 GB GB9002268A patent/GB2229453A/en not_active Withdrawn
- 1990-02-01 WO PCT/GB1990/000160 patent/WO1990008844A1/en not_active Application Discontinuation
- 1990-02-01 CA CA 2046335 patent/CA2046335A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| EP0456679A1 (en) | 1991-11-21 |
| GB2229453A (en) | 1990-09-26 |
| JPH04503085A (en) | 1992-06-04 |
| WO1990008844A1 (en) | 1990-08-09 |
| GB9002268D0 (en) | 1990-03-28 |
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