CA1133848A - Electrodeposition of composite coatings from a barrel - Google Patents

Electrodeposition of composite coatings from a barrel

Info

Publication number
CA1133848A
CA1133848A CA318,463A CA318463A CA1133848A CA 1133848 A CA1133848 A CA 1133848A CA 318463 A CA318463 A CA 318463A CA 1133848 A CA1133848 A CA 1133848A
Authority
CA
Canada
Prior art keywords
barrel
particles
article
solution
slurry
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
Application number
CA318,463A
Other languages
French (fr)
Inventor
Eric C. Kedward
Colin A. Addison
Francis J. Honey
John Foster
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Baj Vickers Ltd
Original Assignee
Baj Vickers Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Baj Vickers Ltd filed Critical Baj Vickers Ltd
Application granted granted Critical
Publication of CA1133848A publication Critical patent/CA1133848A/en
Expired legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25DPROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D15/00Electrolytic or electrophoretic production of coatings containing embedded materials, e.g. particles, whiskers, wires
    • C25D15/02Combined electrolytic and electrophoretic processes with charged materials
    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25DPROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D17/00Constructional parts, or assemblies thereof, of cells for electrolytic coating
    • C25D17/16Apparatus for electrolytic coating of small objects in bulk
    • C25D17/18Apparatus for electrolytic coating of small objects in bulk having closed containers
    • C25D17/20Horizontal barrels

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Chemically Coating (AREA)
  • Electroplating Methods And Accessories (AREA)

Abstract

ABSTRACT OF THE DISCLOSURE
A process of and apparatus for coating an article with a layer of metal incorporating particles. The article is placed in a barrel together with the particles and the barrel is placed in a plating bath and rotated therein about a horizontal axis. The barrel has an opening covered by a cover which is pervious to the solution but impervious to the particles. The article is thus flowed over by solution within the barrel which can have a high concentration ofparticles but there are no particles in the part of the bath outside the barrel.The process may be electroless or electrolytic. In the latter case, the anode is preferably outside the barrel.

Description

1133~8 This invention relates to processes and apparatus for the electro-deposition of composite coatings which consist of a metal matrix containing particles, in which processes the particles are co-deposited with the metal from a solution in which the particles are insoluble. The invention is primarily concerned with the electrodeposition of coatings incorporating ceramic particles but the particles may be of cermet or metal. Such coatings may be used for various purposes including wear and abrasion resistance, corrosion and oxidation resistance and improvement in coefficient of friction (lubricity) and anti-fretting and anti-galling properties. In certain cases the coatings themselves may constitute the final product after removal of a substrate. The process comprises electrodeposition in a bath containing insoluble particles dispersed in the bath, the particles being co-deposited with the metal deposited from the bath. The process and apparatus of the invention may be used for electroless deposition but are particularly applic-able to electrolytic deposition.
In British Patent No. 860 291 it is proposed to remove electrolyte containing particles from the bottom of the bath and to reintroduce this electrolyte to the top of the bath so that the particles fall through the bath under gravity; the article which is being coated and which forms the cathode is rotated about a generally horizontal axis so that the falling particles settle on the parts of the article which are uppermost for the time being. It has been found that this system does not provide an even coating , particularly on parts which are of irregular shape. British Patent No. l 218 179 describes a process in which the article is suspended without movement in a bath and the particles are maintained in suspension in the bath by circulating the solution, gas being admitted to the container to produce a generally upward flow of solution and gas in the vicinity of the surface on which deposition is occurring. Another construction is ~' 11338~8 described in British Patent No. 1,329,081 in which the solution is agitated by movement generally up and down of a generally horizontal perforated agitator in the solution below the part being coated.
Both these arrangements have proved extremely satisfactory in use but~ both require large volumes of solution and particles, and this is expensive. In addition, considerable energy is required to maintain the large volume of the bath homogeneous.
According to the present invention, a process of coating an article with a layer of metal incorporating particles comprises placing said article and particles within a hollow barrel, support-ing said article therein, immersing said barrel in a plating solution whereby said particles form a slurry at the bottom of said barrel, at least part of the wall of said barrel being impervious to said particles but pervious to said solution, rotating said barrel at a speed not greater than four revolutions per minute about a horizontal axis or an axis which is slightly inclined to the horizontal, and codepositing metal and particles onto the article, whereby said codepositing is provided by said slurry being carried up on the interior of said barrel by said rotation, falling onto said article as a dense layer and sliding off said article.
The present invention may be more particularly defined as a process of electroplating an article with a layer of cobalt incorporating chromium carbide particles, the process comprising:
supporting said article in a hollow barrel having internal paddles;
placing in said barrel chromium carbide particles in an amount of at least 2 kilograms per liter of capacity of said barrel; immersing said barrel in a cobalt plating solution whereby said particles form a slurry at the bottom of said barrel, at least part of the wall of ~338~8 said barrel being impervious to said particles but pervious to said solution; providing a cobalt anode in said solution outside said barrel; rotating said barrel about a substantially horizontal axis at a speed not greater than two revolutions per minute; and passing an electric current between said article and said anode, whereby said electroplating is provided by said slurry being carried up on the interior of said barrel by said rotation, falling onto said article as a dense layer and sliding off said article.
Due to the rotation of the barrel about a non-vertical axis, particles fal7ing under gravity towards that part of the barrel which is loweæt will be carried upwards by rotation of the barrel and will again fall through the solution. Thus, in addition to the turbulence which will be caused by rotation of the barrel, there will also be circulation of the particles which will be falling under gravity and being carried upwardly again by rotation of the barrel.
With this construction it is possible to employ a small quantity of particles and a higher rate of inclusion of particles is obtained.
The reduction in particle inventory is particularly advantageous where valuable particles such as diamond are employed.
To improve circulation of the particles, it is preferred for the barrel to contain paddles rotating therewith, the paddles being formed by axially extending ribs on the interior surface of the barrel. In most cases the article to be plated will be rigidly supported within and from the barrel, - 2a -il338~8 but advantages may be obtained in certain cases by supporting the article separately from the barrel so that the artlcle is held stationary or rotates about the axis of rotation of the barrel or another axis at a speed which is different from the speed of rotation of the barrel. In an alternative arrangement the interior surface of the barrel is conductive and is connected into the plating circuit and the part or parts to be plated are loose within the barrel so that they tumble as the barrel rotates.
Where the process is used for electroless plating, the solution ,~ ~ os~oh or~
~ will be of appropriate composition, for example a nickel-iron electroless plating solution with diamond particles in the barrel. Where the process is used for electrolytic plating, the solution will be of appropriate com-position, for example a cobalt plating solution with chromium carbide part-icles in the barrel, and the process will include passing an electric current between an anode in the solution and the article.
By use of the process, it is possible to cause a stream of solution heavily loaded with particles to flow gently over the surface to be plated without stagnation occurring. The heavy loading is achieved in a restricted area, i.e. within the barrel, while there is a larger volume of solution whose characteristics, e.g. temperature, concentration and homogeneity, can more easily be maintained constant than could a smaller volume. The space outside the barrel can be utilised for such items as heaters, agitators and, in the case of electrolytic plating, anodes which in the previous processes have been located in the solution containing particles.
Figure 1 is a somewhat diagrammatic side elevation of apparatus for performing a process of electrodeposition of composite coatings, part of the tank wall being broken away to show the apparatus within;
Figure 2 is a side ele~ation of the drum of the apparatus shown in Figure 1 to a slightly enlarged scale;

i~W~8 :
Figure 3 ls an end elevation of the drum shown in Figure 2; and Figure 4 is an exploded view of one composite closure panel for the barrel.
The apparatus shown in the drawings comprises a tank 1 to contain a bath of electrolyte 2. A framework 3 having uprights 4 and a horizontal 5 extends over the bath to support by means of S-hooks 6 a frame 7 which depends into the bath 2 and carries bearings 8 in which trunnions 9 and 10 rotate. The trunnions are attached to the opposite end walls 11, 12 of a . .
hexagonal hollow barrel 13 comprising six walls 14 each of which contains a rectangular aperture 15 closed by a composite cover 16 the construction ;. of which is shown in more detail in Figure 4. Each cover comprises a rec-tangular frame member 17 having a plurality of holes 18 through which studs 19 attached to the respective wall 14 of the barrel 13 can pass. The frame traps between itself and the wall 14 a sandwich constituted by two outer layers 20 of porous neoprene and an inner layer 21 formed by filter paper.
The neoprene layers, which are 3 millimetres thick, have a nominal pore size of 10 micrometres ~m) while the filter paper has a nominal pore size : of 2 ~m.
The barrel can be rotated by means of an electric motor 22 support-- 20 ed by the upper horizontal of the frame 7 and connected to the trunnion 10 by a gear wheel 23 on the motor output shaft, an idler wheel 24 mounted on an upright of the frame 7, and a gear wheel 25 mounted on the trunnion 10.
: The barrel contains paddles 30.
As can be seen in Figure 2, the inner end of the trunnion 9 extends axially into the barrel and terminates in a threaded spigot 26 on which can be screwed a mounting jig 21 carrying a part 28 to be coated, in this case a turbine stator blade having platforms at each end.
The apparatus includes an air blower 31 connected by a flexible ;' .

:',' .

11338~8 pipe 32 to a horizontal outlet pipe 33 in the base of the tank 1, the outlet pipe 33 having a number of apertures in its upper surface so that when the blower 31 is in operation air can be bubbled into the solution.

Using the apparatus described, a stainless steel panel two inches by one inch by one-eighth of an inch was provided with a composite coating comprising a cobalt matrix including particles of chromium carbide. The tank was filled with a solution comprising 450 grams per litre of cobalt sulphate, 30 grams per litre of boric acid and 12.5 grams per litre of sodium chloride. To 125 litres of this solution contained in the tank was wcr~
~; added 10 millilitres of Canning's anti-pit liquid and there wa~ supported -~ in the bath four anodes 34 comprising cobalt chips contained in titanium baskets surrounded by anode bags.

The panel to be coated was given a pretreatment comprising immers-~ J~s ion in a cyanide cleaner for two ~ff~e followed by a water rinse, etching by immersion for 30 seconds in 50% sulphuric acid followed by a water rinse, and a nickel strike by plating in a nickel bath for three minutes at a current density of 3.9 amps per square decimetre. The panel was secured in the plating barrel in the manner described for the stator blade 28 shown in Figure 2 and the panel was connected to a cathode contact. Sufficient chromium carbide powder with a mean particle size of 2 to 5 ~m was added to the barrel in an amount to provide 2500 grams per litre of barrel capacity and the opening in the barrel through which the panel to be coated and the powder were admitted was closed by the attachment of a cover 16. The barrel was then completely submerged in the solution in the bank and was rotated at three re~olutions per minute while composite plating took place at a ~oltage of between 2.5 and 3 Yolts w~th a current density of approximately
2.7 amps per square decimetre. The solution temperature was maintained at ..

li;~3~ ~8 50C and the solution had a pH of between 4.5 and 5. After plating had proceeded for a time sufficient to give a thickness of plating of 0.05 mm, plating was stopped and the panel was examined. It was found that the panel had been given a tenacious coating having an even distribution of particles with a particle content of approximately 28.9% by weight and 35.2% by volume.
The barrel capacity was 6 litres.
A series of experiments using the process and apparatus described in the aforementioned British Patent No. 1 218 179 but otherwise using the conditions of the Example set out above and with a progressively increasing loading of particles has indicated that the proportion of particles in the coating increases little, if at all, as the loading rises above 400 grams per litre at which level the proportion was found to be about 23%. A series of experiments using the apparatus shown in Figures 1 to 4 and following the procedure set out in the Example above produced the following results:

Bath loading Particle Inclusion ~Weight %) 600 22.6 700 23.1 1000 24.9 1500 26.5 250~ 2~.9 300~ 33.2 It will be seen that the limit which occurs with the process described in British Patent No. 1 218 179 does not occur with the process described in the present specification.
EXAMPLE II
The apparatus described was used for electrolessly plating a stain-11338~8 less steel panel tw~ inches (50.8 mm) by one inch (25.4 mm) by one-eighth of an inch (3.2 mm) thick with a composite ooating comprising a neckel-phosphorus matrix inclt~;ng diamand particles. m e tank was filled with a proprietary electroless nickel-phosphorus plating solution known as Niklad-794 and sold by Lea Manufacturing Limited of BuKton, Derbyshire, England. The bath was made up of equal parts of 794A diluted to 80 millilitres/litre and 794B diluted to 150 ml/l.
The panel to be coated was given the same pretreatment as in example 1 and secured in the barrel in the same way. Sufficient diamDnd powder was added to the barrel to provide 35 gms/l of barrel capacity, that is mDre than four times the nickel content of the same quantity of solutior.. m e barrel was then closed and ccmpletely submerged in the solution in the tank and was rotated at three revolutions per minute. To initiate the electroless deposition, a volt-age of 2 volts was established between the article and the ancdes for between five and ten seconds and was then switched off. Electroless deposition was allowed to continue for one hour. It was found that the panel then carried a homDgeneous and tenacious deposit 20 micrometres thick and containing between 20 and 25 percent by volume of diamand powder in a nickel-phosphorus matrix. This may be compared with between 15 and 20 percent by volume of diamDnd powder con-tained in deposits using similar conditions but using the process and apparatus ! described in the aforementioned British Patent No. 1 218 179.
;

.'. ~.
. .

Claims (5)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process of coating an article with a layer of metal incorporating particles, the process comprising placing said article and particles within a hollow barrel, supporting said article therein, immersing said barrel in a plating solution whereby said particles form a slurry at the bottom of said barrel, at least part of the wall of said barrel being impervious to said particles but pervious to said solution, rotating said barrel at a speed not greater than four revolutions per minute about a horizontal axis or an axis which is slightly inclined to the horizontal, and codepositing metal and particles onto the article, whereby said codepositing is provided by said slurry being carried up on the interior of said barrel by said rotation, falling onto said article as a dense layer and sliding off said article.
2. A process according to claim 1 wherein said plating solution is an electrolytic plating solution and the process includes passing an electric current between an anode in said solution outside said barrel and said article.
3. A process according to claim 1 or claim 2 wherein circulation of the particles is aided by paddles contained in the barrel and rotating therewith.
4. A process according to claim 1 or claim 2 wherein said particles are chromium carbide particles and said solution is a cobalt plating solution.
5. A process of electroplating an article with a layer of cobalt incorporating chromium carbide particles, the process comprising: supporting said article in a hollow barrel having internal paddles; placing in said barrel chromium carbide particles in an amount of at least 2 kilograms per liter of capacity of said barrel; immersing said barrel in a cobalt plating solution whereby said particles form a slurry at the bottom of said barrel, at least part of the wall of said barrel being impervious to said particles but pervious to said solution; providing a cobalt anode in said solution outside said barrel; rotating said barrel about a sub-stantially horizontal axis at a speed not greater than two revolutions per minute; and passing an electric current between said article and said anode, whereby said electroplating is provided by said slurry being carried up on the interior of said barrel by said rotation, falling onto said article as a dense layer and sliding off said article.
CA318,463A 1977-12-21 1978-12-21 Electrodeposition of composite coatings from a barrel Expired CA1133848A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB5332577 1977-12-21
GB53325/77 1977-12-21

Publications (1)

Publication Number Publication Date
CA1133848A true CA1133848A (en) 1982-10-19

Family

ID=10467386

Family Applications (1)

Application Number Title Priority Date Filing Date
CA318,463A Expired CA1133848A (en) 1977-12-21 1978-12-21 Electrodeposition of composite coatings from a barrel

Country Status (8)

Country Link
JP (1) JPS54115643A (en)
BE (1) BE872974A (en)
CA (1) CA1133848A (en)
DE (1) DE2855054A1 (en)
FR (1) FR2412626B1 (en)
IT (2) IT7852357A0 (en)
NL (1) NL186917C (en)
ZA (1) ZA787185B (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59123792A (en) * 1982-12-28 1984-07-17 Toshiba Corp Wear resistant coating
JPH0124146Y2 (en) * 1985-05-02 1989-07-21
FR2617510B1 (en) * 1987-07-01 1991-06-07 Snecma METHOD FOR THE ELECTROLYTIC CODEPOSITION OF A NICKEL-COBALT MATRIX AND CERAMIC PARTICLES AND COATING OBTAINED
AU7522698A (en) 1997-04-11 1998-11-11 Inter Transtech S.R.O. Coating method for elongated metal blanks
CN110144572A (en) * 2018-02-12 2019-08-20 威测国际能源材料有限公司 The film plating process of metalwork
CN110144571A (en) * 2018-02-12 2019-08-20 威测国际能源材料有限公司 The filming equipment of metalwork

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE752952C (en) * 1940-09-29 1951-08-16 Finzler Process for the electrolytic bonding of high-quality abrasives, e.g. B. Diamantkoerner, in metal for the production of grinding tools
US3468890A (en) * 1966-06-09 1969-09-23 Sterling Drug Inc Pyrazino(1',2':1,2)pyrido(3,4-b)indoles
US3498890A (en) * 1967-03-27 1970-03-03 Melpar Inc Preparation of fiber-metal composites by electrodeposition

Also Published As

Publication number Publication date
ZA787185B (en) 1980-08-27
FR2412626A1 (en) 1979-07-20
FR2412626B1 (en) 1985-06-14
IT1107577B (en) 1985-11-25
JPS6213440B2 (en) 1987-03-26
NL186917B (en) 1990-11-01
JPS54115643A (en) 1979-09-08
DE2855054A1 (en) 1979-07-05
NL7812367A (en) 1979-06-25
DE2855054C2 (en) 1988-08-11
IT7852357A0 (en) 1978-12-19
IT7852418A0 (en) 1978-12-21
NL186917C (en) 1991-04-02
BE872974A (en) 1979-06-21

Similar Documents

Publication Publication Date Title
US4305792A (en) Processes for the electrodeposition of composite coatings
US5266181A (en) Controlled composite deposition method
CA1063966A (en) Electroplating method
Foster et al. The production of multi-component alloy coatings by particle codeposition
US4214952A (en) Electrochemical treatment process
US3922208A (en) Method of improving the surface finish of as-plated elnisil coatings
CA1133848A (en) Electrodeposition of composite coatings from a barrel
RU2127333C1 (en) Electrodeposited composite coating and method of coating deposition
US3884772A (en) Method for producing a heat exchanger element
US3699014A (en) Vibratory process
Graydon et al. Suspension electrodeposition of phosphorus and copper
JPS58207398A (en) Composite plating method
US4645580A (en) Process for galvanic deposition of a dispersion coating, application of said process and device for performing said process
US5372701A (en) Process and apparatus for electroplating
Dobrovolska et al. Oscillations and self-organization phenomena during electrodeposition of silver-indium alloys. Experimental study
Yee-Shyi et al. Wear resistant nickel composite coating from bright nickel baths with suspended very low concentration alumina
KR100426159B1 (en) Electrodeposition method of metal film and apparatus therefor
US4172771A (en) Method and apparatus for electrolytically producing compound workpieces
US4696728A (en) Apparatus for mass electroplating of bulk goods
GB2182055A (en) Improvements relating to electrodeposited coatings
US4916098A (en) Process and apparatus for manufacturing an electrocatalytic electrode
JPS5989788A (en) Method for electroplating staple fiber having electric conductivity
Wery et al. Barrel zinc electrodeposition from alkaline solution
RU1768670C (en) Device for application of compositional galvanic coating
JP2673829B2 (en) Manufacturing method of copper-coated iron powder

Legal Events

Date Code Title Description
MKEX Expiry