CA1036841A

CA1036841A - Aluminum-coated nickel or cobalt core flame spray materials

Info

Publication number: CA1036841A
Application number: CA198,685A
Authority: CA
Inventors: Ferdinand J. Dittrich; George J. Durmann; Herbert S. Ingham (Jr.)
Original assignee: Metco Inc
Current assignee: Metco Inc
Priority date: 1973-07-06
Filing date: 1974-05-01
Publication date: 1978-08-22
Also published as: FR2236015B1; GB1460086A; DE2432061C2; DE2432061A1; FR2236015A1; JPS5536066B2; IT1013258B; JPS5021942A

Abstract

Abstract of the Disclosure A flame spray material in the form of a composite comprising (1) as a first component an alloy containing at least about 40% of its weight of at least one of nickel and cobalt, and about 1 to 6% by weight of boron, and (2) aluminum powder as a second component, the first component being present in about 66 to 99% by weight of the composite. The material, desirably blended with about 10% of an aluminum-molybdenum-coated nickel fore powder, produces self-bonded wear resistant coating which can be ground without cracking. The flame spray material can be used to line metal surfaces with other metals of different mechanically superior properties to obtain the best properties of both metals.

Description

The invention relates to an alumlnum-clad nlckel-cobalt-boron based flame spray materlal which i8 characterlzed by excellent bondlng and workablllty of coated surfaces.
It is common to line metal surfaces with other metals of tifferent mechanically superior properties to obtain the beat properties of both metals, e.g. cylinders in aluminum engine blocks have been lined with iron sheets to give the bene-fits of the light weight of aluminum and the wear properties of iron. An improvement thereon involved flame spraying the wear surface onto the receiving surface. To ensure a secure bond between substrate and sprayed metal it was customary to - q~

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; prepare the substrate by mechanical roughening. U. S. Patent

2 Nos. 2,588,421 and 2,588,422 made a furhter improvement thereon 'I
in that molybdenum was first flame sprayed onto the substrate ~ ¦
4 without need for special preparation of the substrate. There-after a hard wear surface such as high carbon steel could be ;
6 sprayed and the laminate would be securely held together.
7 In U. S. Patent No. 2,875,043 there were disclosed 8 spray-weld alloys, also known as self-fluxing alloys, 9 comprising nickel bases which could be sprayed and which, because of a content of boron and/or silicon, act as a fluxer 11 of the alloy and of the surface to be alloyed during subsequene 12 fusing of a sprayed coating. Other metallic components such ;~
13 as chromium, iron, carbon, copper and molybdenum could also 14 be present. In U. S. Patent No. 2,936,229 it was taught that such self-fluxing alloys might also contain about 0.2 to 5~L
16 of aluminum and that the nickel could be replaced in whole 17 or in part by cobalt. These modifications minimized the 18 formation of any small pores in the coating. Other elements could also be present in mi-nor amounts.
For certain purposes it was desired th~t the flame 21 sprayed surface constitute an intermetallic compound. In 22 U. S. Patent 3,305,326 there was disclosed a powder mixture 2~ as described in U. S. Patent Nos. 2,875,043 and 2,936,229 along J, 24 with coated powder particles comprising a metal nucleus and a metal coating reactable therewith at flame spray temperatures - 26 to form an intermetallic compound. The coated powder material ; rendered the blend self fusing, i.e. it automatically formed 28 a fused coating upon spraying without a separate fusing operatic n.

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~ l ~ 1C~3~i841 l In U. S. Patent No. 3,322,515 there were described modified flame spray composite materials whose components exothermically

3 interacted with one another when melted so as to form such

4 intermetallic compound which was deposited upon the substrate.
The heat generated by the exothermic reaction aided in the 6 bonding, and these materials were an improvement over Ij 7 molybdenum for bonding other flame spray materials to the ! substrate. The composite could comprise separate strands of 9 the two components, e.g. a strand of nickel and a strand of I lO aluminum, the strands being simultaneously fed to a flame i ll spray gun. In accordance with a preferred technique one 12 of the components could be coated onto the other, e.g.
13 a wire comprising a nickel core and an aluminum sheath.
14 These composites functioned in generally satisfactory fashion but had certain significant limitations. For example 16 the self-fusing mixture of U. S. Patent No. 3,305,326 did not 17 bond very well, and required either a special substrate 18 preparation such as roughening by grit blasting, or a lg preliminary layer of a bonding material such as molybdenum or exothermic composite described above 21 The surfaces, while of adequate bond strength for 22 most purposes, still imposed limitations upon the working Z3 to which the coated surfaces could be put.
24 It is accordingly an object of the present invention 2~ to provide flame sprayable compositions which are self-26 bonding and which produce coatings which may readily be worked without de-bonding.

_ 3 _ , . i A further object of the invention is to produce superior flame sprayed bearing surfaces.
These and other objects and advantages are realized in accordance with the present invention pursuant to which there is provided a flame spray material in the form of a composite comprising (1) as a first component an alloy con-taining at least about 40~ of its weight of at least one of nickel and cobalt, and about 1 to 6% by weight of boron and (2) aluminum powder as a second component, the first component being present in about 66 to 99% by weight of the composite.
The resulting coatings are characterized by excellent bonding and superior bearing and wearing surfaces. They can readily be worked, generally by grinding.
The first component, which preferably constitutes about 66 to 99% and most preferably about 85 to 95%
of the combined weights of the first and second components, may ~omprise any of the spray-weld, self-fluxing alloy compositions disclosed in above-mentioned U.S. Patent Nos. 2,875,043 and 2,936,229. Thus, the first component may further contain about 1 to 6% of its weight of silicon, preferably about 4 to 5~; up to about 20% of chromium; up to about 8~, and generally at least about 3% when present, of copper, preferably about 5 to 6~; up to about 10%, and generally at least about 3% when present, of ~molybdenum, preferably about 4.5 to 5.5%; and aluminum desirably in about 0.2 to 5% and preferably up to about 2%. Minor amounts of iron and carbon may also be present. While the nickel and/or cobalt should constitute cmj .. , 5. ,, ~ .. , .. ,~. ... . , .. . ,. , . ,, ~ ... . ... . . . .

st least about 40~ o~ the 1rst co~ponent as descrlbet, advan-tageously lt should constltute at least about 60%.
The secont component, a6 notet, comprises aluminu~ and preferably lt ls employed as a flne powter teposltet ln a blnder on partlcles of the first component.
The aluminum preferably ln as finely divitet form as possible, as for eYample a size of -325 mesh, is mixed in the requlret proportions with a binder or lacquer 80 as, in effect, to form a paint in which the aluminum particles correspond to the pigment. The paint is then used to coat the core particles and allowed to set or try.
The binder material may be any known or conventional binder material which may be uset for forming a coating or for bonding particles together or to a surface. The binder is pre-ferably a varnish containing a resin as the varnish solids, and may contain a resin which does not depend on solvent evaporation ln orter to form a dried or set film. The varnish may thus contain a catalyzed resin as the varnish solids. Examples of binders which may be uset include the conventional phenolic epoxy or alkyt varnishes, varnishes containing drying oils, such as tuna oil and linseed oil, rubber and latex binters and the like.
The coating of the high nickel-cobalt first or core com-ponent with the "paint" containing the aluminum may be effected in any known or desired manner, and it is simply necessary to mi~ the two materials together and allow the binder to set or dry which will result in a fairly free-flowing powder consisting of the nickel-cobalt core coatet with cladting of the aluminum.
The powders are sprayet in the conventional manner, using a powter type flame spray gun, though it is also possible to combine the same in the form of a wire or rod, using plastic or a similar binding, as for eYample polyethylene which decomposes tb~,~ 5 103~841 ln a heatlng zone of the gun. When formed a~ wire~, the sa~e may have conventional si~es and accuracy tolerances for flame spray wlres and thus, for example, may vary in slze between 1/4" and 20 gauge.
The spraying i9 in all respects effected in the conven-tional manner previously utilized for self-bonding flame spray material, and in particular nickel aluminum composites. Due to the self-bonding characteristics, special surface preparation other than a good cleanlng is not required though, of course, conventional surface preparation may be utilized if deslred.
The powder in accortance with the invention may be flame-~prayed as a bonding coat for subsequently applied flame spray material. The composites may furthermore be sprayet in con-~unction with. or in addition to, other flame spray materials conventionally used in the art.
When sprayed, the nickel and/or cobalt and aluminum are believed to react exothermically, forming a nickel and/or cobalt aluminide intermetallic. Complex aluminides and alloys with other metals, when present, may be formed.
The term "composite" as used herein is intended to designate a structurally integral unit and does not include a mere mixture of components which may be physically separated without any destruction of the structure. Thus, in the case of powder, the term "composite" does not include a simple mixture of individual granules of the separate components, but requires th~t each of the individual granules contain the separate com-ponents which will exothermically react, forming intermetallic compounds. In the case of wire, the individual components must be incorporated in a single wire. In the composite the com-ponents must be in intimate contact with each other.
In connection with powders, each grain may consist of an ~ggregate containing the components which wlll exothermically db/~ - 6 -rea^t, form~ng the lntermetallic compount, but preferably the lndivldual grains of the powter are in the form of a clad com-poslte consisting of a nucleus of one of the components ant at least one coatlng layer of the other components. Alternatively, the composite may consist of separate, concentric coating layers of at least two of the components ant a nucleus of two, three or even a fourth material.
In the case of wires, the composites may be in the form of a wire having a coating sheath of one material ant a core Of the others, alternate coating sheaths u4 two of the components and a core of the thirt or a fourth material, a wire formed by twi~ting o~ rolling separate wire strands of the components, a wlre consisting of a sheath of one component and a core con- .
tsining the other components in powder or compacted form, a ~lre consisting of a sheath of one component and a core containing a compacted powter mixture of this same component material and other components, a wire consisting of a plastic sheath and a core containing a compacted powder mixture of components, etc.
In order for the wires to be most satisfactory for spraying, it is preferable that the same must not cavitate at the tip when heatet, and should preferably be capable of forming a polnted or ~lightly tapered tip when being melted and sprayed.
Thus, if the wires have an outer layer or sheath of one component and an inner core of another component, the inner core should not have a lower melting point than the outer sheath, as other-~ise the inner core will initially melt, causing cavitation at the tip. For example, if the wire is in the form of a core with a coating sheath, the coating sheath should be aluminum, as otherwise during the spraying operation the wire will initially melt out, causing the cavitation which may interfere with a s-tisfactory spraying operation. The wire havlng the melting-point characterigtics so as to allow the ~elting off of the tip tb/~ 7 -wlthout thl~ cavitation i9 referred to herein and in the claims as "non-cavltating wire."
Whlle the components may be present ln the stolchio-metrlc proportions requlret for the formation of the lnter-metallic compound, it is, however, possible to also have an excess of one or the other provided the relative amounts are sufficient to release quantities of heat in the formation of the intermetallic compounds.
The clad powders, in accortance with the invention, may be formet in any known or desiret manner, including known chemical plating processes, in which coating material i8 deposited on a seed or nucleus of another material, or in which multiple lsyers of various materials are built up on the seet material, or in which various materials are co-tepositet in a single lsyer on the seed material.
A mote of forming the clad powders lnvolves the déposi-ting of a metal from a solution by reduction on a seed or nucleus, such as by the hydrogen reduction of ammonical solutions of nlckel and/or cobalt aad ammonium sulfate on a seed powter catalyzet such as by the atdition of anthraquinone. It is also possible to form the coating by other processes, such as coating by vapor deposition, by the thermal decomposition of metal car-bonyls, by hydrogen reduction of metal halite vapors, by thermal deposition of halides, hydrides, carbonyls, organometals, or other volatile compounds, or by displacement gas plating and the like.
A preferred and greatly simplified mode of forming the clat powders in accordance with the invention is the depositing of one component as coating in the form of a paint on the other component. ThuR the component which is to form the coating or cladting may be dispersed in finely tividet form in a binder or lac~uer so as, in effect, to form a palnt in which this component db/~ - 8 -` 10368~1 corresponds to the pigment. The palnt i8 then used to coat core partlcles of the other component and the binder or lacquer allowed to set or dry. The blnder materlal 19 preferably a resin which does not depend on solvent evaporatlon ln order to form a dried or set film, and which film will decompose or break down in the heat of the spraying process. The binder, for example, may be a phenolic varnish or any other known or conventional varnish, preferably conta~ning a resin as the var-nish solids. The components which are initially mlxed with the blnder or varnish should preferably be as finely divided as possible, as for example -325 mesh. The other component which constitute6 the core should be approximately or only s~lightly below the particle size ultimately desired for the spray powder.
The coating of the core component with the "paint" may be effected in any known or desired manner, and it is slmply necessary to;
~ls the two materials together and allow the binder to dry or ~et, which will result in a fairly free-flowing powder consisting of the core component coated with a cladding of the other com-ponent bound in the binder.
The aggregates may be formet by any other known method, suc~ as by compacting or briquetting the various components into the lndividual granules, or into larger aggregates and then breaking these aggregates into the granules.
The wires may be formed in the known conventional man-ner for forming wires with various components as, for example, by shrinking a sheath on a core, by forming the core with powder, by twisting the component wires, followed by rolling, drawing, swagging, or the like if tesired.
In accordance with one mode of manufacture, one of the components may be formed into a tube or sheath and filled with a powder of the other component or a powder comprising a mixture of the two components, vr containing atditional components. The db¦~ ~ 9 ~
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tube ends are then sealed and the wlre reduced to the desired w$re tlameter by swagging, rolllng or drawlng. Preferably the powder or powder mlxture is flr~t compressed into cylindrical briquettes before being placed in the sheath or core. The ~eallng of the tube ends after loading with the powder or pow-der mlxture can be effected, for lnstance, by insertion of a plug, for example of the metal of the sheath, by welding, twlsting, crimping, or the like.
Powders in accordance with the invention should have 10 the general over-all shape and size of conventional, flame spray powders, and thus for example should have a size between -60 mesh and +3 microns and preferably -140 mesh and +10 microns (U.S. Standard screen mesh size). Most preferably the powder should be as uniform as posslble in grain size, with the indivi-dual grains not varying by more than 250 microns and preferably 75 microns.
Dependlng on the partlcular flame spray process and the tesiret purpose, the composite powder may be sprayet per se or ln co~bination with other different composlte powders, or in 20 combination wlth other conventional flame spray powders or powder components.
- While the powders are preferably sprayet, as such, in a powder-type of flame spray gun, it i5 also possible to combine the same in the form of a wire or rod, using a plastic or simi-lar binder, which decomposes in the heating zone of the gun, or in certain cases the powders may be compacted and/or sintered together ln the form of a rod or wire. The wires must have the conventional sizes and accuracy tolerances for flame spray wires and thus for example may vary in size between 1/4" and 20 gauge, ~0 and are preferably of the following sizes: 3/16" + .0005" to -.0025", l/8" t .0005" to -.0025", ll gauge ~ .0005"
to -.0025", and 15 gauge + .OOOl" wlth a smooth clean finish tb/ ' ' - lO -........ ~ .. ~, .... . . . .

-"` ` 1036841.
free from surface marks, blemlshes, or defects. The wires are sprayet in the conventional manner uslng conventlonal ~lre-type flame spray guns.
In combining, in the exothermic reaction, forming the lntermetallic compound, the components generate heat ln situ in the actual material which is to form at least a part of the coating. This is to be distinguished from flame-spray processes ant materials in which heat is generated by a reaction, such as 8n oxitation reaction in whlch a oreign ant non-metallic element is introduced ant in which untesirable components may be pro-ducet. Asite from greatly contributing to the thermal efficiency of the process, the heat generated in situ in the formation of the intermetallic compount produces novel results, in many in-stances forming a tenser, more adhering coating, having charact-eristic~ ~ at least a partially fused coating. In many in-stances the coating has self-bonting characteristics, so that ~pecial surface preparation, other than a good cleaning, is not requiret. The spraying in all other respects is effected in the conventional, well-known manner, using conventional flame spray equipment, ant the conventional surface preparation may be utilizet, if tesired. The composites in accordance with the invention may be sprayet in con~unction with or in addition to other flame spray materials db~
.

conventionally used in the art, or may be sprayed in combination or conjunction with the others.
The use of the nickel- and/or cobalt- aluminum composites will generally improve the bond of the total sprayed material, and thus of the other component or components, to the substrate, sometimes making the mixture self-bonding. The particle bond will be improved and the coating will be denser, 80 that its porosity may be decreased. In general, as little as about 5% by weight of the composites in accordance with the invention will be sufficient to substantially improve the bonding characteristics and decrease the porosity of other flame spray materials, such as conventional flame spray metals, alloys or ceramics. There is, of course, no upper limit on the amount as the composite may be sprayed per se.
An especially suitable blend comprises the novel composite and up to about 20% of its weight, preferably about 5 to 15% of its weight, of another composit~. The other composite may simply be aluminum-clad nickel although preferably it is aluminum- and molybdenum-clad nickel as described more fully in Canadian Application Serial No. 198,563 filed April 30, 1974. In such other composite based on the weight of nickel, aluminum and molybdenum the nickel is present :n about 66 to 97.5%, the aluminum in about 2 to 18% and the molybdenum in about 0.5 to 16%; preferably the nickel is present in about 73 to 89%, the aluminum in about 5 to 15% and cm/ 1 2 ..~

10;16841 l the molybdenum in about 6 to 12%. Such other compo8ite which 2 is preferably a clad core is generally produced in the same 3 manner as described hereinabove for the composite forming 4 I the basix of this in~ention. Such blends produce coatings which will not crack upon working even when extremely thick, 6 e.g. more than about 0.050 inch and even more than about ¦ 0.100 inch.
8 Materials with which the novel composites may be 9 admixed before flame spraying include carbides as described l I 10 in U. S. Patent No. 3,305,326. ~hen blended with a refractory i ¦ ll carbide, such as tungsten carbide, titanium carbide, zirconium l ¦ 12 carbide, tantalum carbide, columbium carbide, hafnium carbide, , 13 chromium carbide or the like, extremely high quality coatings 14 are produced, which are superior in various respects to the conventional carbide coatings. li 16 The carbides used in accordance witl this embodiment 17 should have a particle size between about -140 mesh U. S.
18 Standard screen size and 8 microns, and preferably between l9 about -270 mesh and ~15 microns, with the amount of carbide being between about 5-95% and preferably 25-85% and most prefer 21 I ably 45-55% by weight, based on the total powder mixture.
22 If the refractory carbide powder is in a form so that 23 the refractory carbide is bound in a matrix, as for example 24 a cobalt or nickel matrix containing S-20% by weight of either cobalt or nickel, unusually hard and wear-resistant 26 coatings will be produced which do not contain the individual 27 carbide particles imbedded in a fused matrix, but instead -` 103684~, contain alloy phase~ who~e micro-hardnes~ i9 actually sub-stanelally hlgher than that ordlnarlly obtalned from a bonded carbide.
When the powder, ln accordance wlth the inventlon, con-tainlng this matrix-bonded refractory carbide is plasma-sprayed, the same is self-bonding, so that the conventlonal surface pre-paration for flame spraying, as for example a deep surface roughening, is not requiret.
The carbide coatings formet in accortance with the above are extremely hart and wear-resistant, and may be useful as bearing surfaces, abrasive surfaces, and for any other purpose wherein a working surface requires extremely wear-resistant coating.
The refractory carbide, need not be matrix-bound, but should be a pure crystalline carbide, also having the particle size and u~ed in the amounts lndicated above. The crystalline carbite-containing coatings formed in accordance with the in-vention will have extremely high wear-resistance due to the carbide particles, which are tispersed ant tightly bound in the fused coating. Coatings may be uset for the same type of ap-plications as mentioned in connection with the coatings formed with the matrix-bound carbide.
The following examples, wherein all parts are by weight unless otherwise expressed, are given by way of illustration and not limitation.

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1 I ~xAMpLE 10;UiE~
¦ Finely divided aluminum powder (-325 mesh) was 3 ¦ admixed with a conventional phenolic varnish having 4 approximately 10% solid contents so as to form a mixture having the consistency of heavy syrup and containing about 60% by weight of the metal particles. 100 grams of the 7 ¦ varnish powder mixture was then added to about 900 grams 8 of a self-fluxing alloy powder comprising -200 +325 mesh partic es 9 of the composition O~15~/o carbon, 2.5% silicon, 2.5% boron, 2.5% iron, 10% chromium, balance nickel. The two were ll thoroughly mixed, with the mixing continued until the 12 varnish dried, leaving a fairly free-flowing powder in 13 which all of the core particles were clad with a dry film 14 which contained the aluminum particles. The powder was then warmed to about 250F. to ensure complete drying. The 16 ¦ powder was then screened and hand-milled to reduce the same 17 ¦ to a -100 mesh powder. The powder was flame-sprayed on a 18 mild steel plate which had been surface cleaned by smooth 19 grinding. The spraying was effected under different conditions using three different flame spray guns sold by 21 I Metco, Inc., of Westbury, N.Y., as described in Table I.
22 The process conditions and the results are set forth in 23 Table II along with those Eor one oE the best grindable .
Z4 compositions heretofore available, which composition however is not self-bonding. The novel coatings are hard, grindable 26 ¦ and durab .

1036~141 Table I
2 ¦ Spray Parameters for a Self-Bondin~ Grindable Coatin~

l (1) (1) (2) 4 METC0 "5P" ThermoSpray METC0 "N" ThermoSPray METC0 "3MB"
Plasma Spray Gun Nozzle = P7G N7B Gas - N2 ~ 2 r Meter Valve - 12 15 Press (psi)-50/50 8 Clicks - 8 9 Flow - 100 ~ 0 9 2 Flow - 25 Press - 0213 Current - 500 AMPS
Acet. Flow - 40 Press Acet. 15 Voltage - 73 Volts 11 Carrier ' 2 2 Carrier = 37 12 Vibrator Vibrator Nozzle - G
13 Spray Dis~. = 10" 7" Port ~ 2 14 Spray Rate - 9 Lbs.~Hr. 6 ~r. "S" Wheel 20 15 ¦Deposit Efficiency = 75% 85% Spray Rate-10 Lbs. 'Hr 16 ¦Hardness - Rc 37 Rc 34 Spray Distance ~ 6 17 Hardness - Rc47-49 18 ¦(1) As described in U.S. Patent No. 2,961,335.
20 1(2' As desc ibed in U.S. Patent No. 3,145,287.

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2 ¦ When 90% of the composite aluminum clad self-fluxing 3 alloy in Example 1 was admixed (blended~ with 10% composite 4 powder of aluminum-molybdenum clad nickel core (Example 1 of S ¦ METC0 347), and sprayed per Example 1, a hard grindable coating 6 ¦ was produced which did not crack upon working even when 7 ¦ extremely thick. The coating also had a bond strength of 8 ¦ 5,260 psi (Table II).
9 . l 11 ¦ Uhen 50% of the 90/O composite aluminum self-fluxing 12 alloy with 10% composite aluminum-molybdenum-nickel powder 13 was admixed (blended) with 50% refractory molybdenum metal 14 ¦ powder, and sprayed per Example 1, a hard, grindable, wear resisting coating was produced. (See U.S. Patent 3,313,633, 16 Example 5 - 50% molybdenum). The coating hardness was Rc 35-40 17 and bond strength was 5,027 psi.
18 l i 20 I When 50% of the 90% composite aluminum self-fluxing 21 I alloy with 10% composite aluminum-molybdenum-nickel powder 22 ¦ is admixed (blended) with 50% of a refractory tungsten carbide 23 ¦ powder (See U.S. Patent 3,305,326 Example 3-crystalline 24 carbide~, a hard grindable coating was produced, with Rc hardnes of 53-S5, and a bond strength of 6,444 psi.

28 _ _ I

1 ~ EXAMPL1 1036841 Repeating Example 4 using 50% of the composite powder 3 of Example l (without the addition of the aluminum-molybdenum- .
4 nickel powder) produces similar results.

It will be appreciated that the instant specification 7 and examples are set forth by way of illustration and not 8 limitation, and that various modifications and changes may 9 be made without departing from the spirit and scope of the 11l02 ~ present ention.

3 .

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- 28 .

Claims

What is claimed is:

1. A flame spray material in the form of a composite comprising (1) as a first component an alloy containing at least about 40% of its weight of at least one of nickel and cobalt, and about 1 to 6% by weight of boron, and (2) aluminum powder as a second component, the first component being present in about 66 to 99% of the combined weight of the first and second components.

2. A flame spray material according to claim 1, wherein the first component comprises about 85 to 95% of the combined weights of the first and second components, said first component containing at least about 60% by weight of nickel and cobalt.

3. A flame spray material according to claim 2, said first component further comprising up to about 6% of silicon, up to about 20% of chromium, up to about 8% of copper, up to about 10% of molybdenum, and up to about 5 % of aluminum.

4. A flame spray material according to claim 1, wherein the second component is secured by a binder to the first component as a core.

5. A flame spray material according to claim 4, wherein said binder is a varnish.

6. A flame spray material according to claim 5, wherein the composite is a powder and the first component comprises about 85 to 95% of the combined weights of the first and second components, said first component containing at least about 60% by weight of nickel and cobalt.

7, A flame spray material according to claim 1, in the form of a blend with up to about 20% by weight of a second composite comprising nickel plus at least one of aluminum and molybdenum, the nickel comprising about 66 to 97.5% the weight of said second composite.

8. A flame spray material according to claim 3, in the form of a powder blend, the composite having the second component secured by a varnish to the first component as a core, the blend including about 5 to 15% of a second composite comprising about 2 to 18% by weight of aluminum, about 0.5 to 16% by weight of molybdenum and about 66 to 97.5% by weight of nickel, the nickel being present as a powder having the aluminum and molybdenum secured thereto by a varnish.

9. A flame spray material according to claim 6, in the form of a blend with up to about an equal weight of a metal carbide or molybdenum.

10. A powder blend according to claim 8 further blended with up to about an equal weight of a metal carbide or molybdenum.

11. In the flame spray coating of a substrate, the improvement which comprises employing a flame spray material according to claim 1.

12. The process of claim 11, wherein the first component comprises about 85 to 95% of the combined weights of the first and second components, said first component containing at least about 60% by weight of nickel and cobalt.

13. The process of claim 12, said first component further comprising up to about 6% of silicon, up to about 20% of chromium, up to about 8% of copper, up to about 10% of molybdenum, and up to about 5% of aluminum.

14. The process of claim 11, wherein the second component is secured by a binder to the first component as a core.

15. The process of claim 14, wherein said binder is a varnish.

16. The process of claim 15, wherein the composite is a powder and the first component comprises about 85 to 95%
of the combined weights of the first and second components, said first component containing at least about 60% by weight of nickel and cobalt.

17. The process of claim 11, wherein the composite is present as a blend with up to about 20% by weight of a second composite comprising nickel plus at least one of aluminum and molybdenum, the nickel comprising about 66 to 97.5% the weight of said second composite.

18. The process of claim 13, wherein the composite is present as a powder blend, the composite having the second component secured by a varnish to the first component as a core, the blend including about 5 to 15% of a second composite comprising about 2 to 18 by weight of aluminum, about 0.5 to 16% by weight of molybdenum and about 66 to 97.5%
by weight of nickel, the nickel being present as a powder having the aluminum and molybdenum secured thereto by a varnish.

19. The process of claim 16, wherein the composite is blended with up to about an equal weight of a metal carbide or molybdenum.

20. The process of claim 18, wherein the blend further contains a metal carbide or molybdenum in up to about an equal weight based on the combined weights of first and second composites.