Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
  • C25D5/48—After-treatment of electroplated surfaces
  • C25D5/50—After-treatment of electroplated surfaces by heat-treatment
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D3/00—Electroplating: Baths therefor
  • C25D3/02—Electroplating: Baths therefor from solutions
  • C25D3/56—Electroplating: Baths therefor from solutions of alloys
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/922—Static electricity metal bleed-off metallic stock
  • Y10S428/9335—Product by special process
  • Y10S428/934—Electrical process
  • Y10S428/935—Electroplating
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/922—Static electricity metal bleed-off metallic stock
  • Y10S428/9335—Product by special process
  • Y10S428/941—Solid state alloying, e.g. diffusion, to disappearance of an original layer
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/12—All metal or with adjacent metals
  • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
  • Y10T428/12681—Ga-, In-, Tl- or Group VA metal-base component
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/12—All metal or with adjacent metals
  • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
  • Y10T428/12736—Al-base component
  • Y10T428/1275—Next to Group VIII or IB metal-base component

Definitions

• the surface of aluminium or an aluminium alloy is s t 4 I973 F 73 3303! treated by electrolytic deposition of a copper-indium ep rance alloy surface layer followed by the diffusion heat treat- 1 U S Cl 204/37 29/197 29/199 ment of the coated surface.
• Electrolysis is carried out 204/44 in a bath containing, in an aqueous alkaline solution, [5H Int Cl C23) slszrcnb 5/46 B23 3/00 monovalent copper ions, trivalent indium ions, an al- 58]
• References Cited the heat treatment is carried out at between 120 and 155C. UNITED STATES PATENTS 2,458,839 1 1949 Dyer, Jr. et a1.
• the present invention relates to a process for the treatment of surfaces of aluminium or aluminium alloys to improve their frictional properties and resistance to wear and seizure by forming on their surface, by diffusion, intermetallic or semi-metallic compounds.
• the second technique permits the use of a lower diffusion temperature and a shorter temperature holding time.
• this coating morphology results in rapid wear of the porous zone and a substantial, progressive increase of the coefficient of friction; at a certain degree of wear there may even be epidermic sticking and seizure.
• the composition of the alloy deposited varies from one point to another on the treated part, and this variation is considerable.
• the copper content of the mixed coating is above 50 percent by weight, the alloy, when subjected to friction, becomes covered with copper, which in practice is incompatible with the usual mechanical parts, particularly steels, which have to rub against parts of the treated aluminium alloys.
• the indium content exceeds 65 percent by weight the hardness of the alloys formed decreases very rapidly and the mechanical characteristics of the layer of alloy become insufficient to prevent the phenomenon of surface creep when friction occurs.
• An object of the present invention is to provide a process by which it is possible, under industrial large-scale production conditions, to obtain on surfaces of aluminium and aluminium alloys a coating having good frictional properties without seizing and without reduced wear, which is capable of following without fracturing any deformation, even substantial deformation, of its substrate, which is not subject to surface creep, and which has a hardness several times greater than that of the uncoated aluminium alloy, while the mechanical properties of the latter are not affected.
• the present invention proposes a process for the treatment of surfaces of aluminium or aluminium alloys by depositing a layer of a copper-indium alloy followed by diffusion heat treatment, characterised in that this deposition is effected galvanically in a bath containing, in an aqueous alkaline solution, monovalent copper ions, trivalent indium ions, an alkali metal hydroxide, an alkali metal cyanide, an alkali metal gluconate, gluconic acid, and oxalic acid, these products being used in accurately defined proportions which, according to the original feature of the invention, must be concurrently respected, and in that the diffusion heat treatment is effected at a temperature between and C.
• anodic current density between 1.5 and 4 A/dm concentrations of gluconic acid and oxalic acid between 1 and mg/litre.
• the part After deposition of the desired thickness, the part is rinsed and dried and subjected to the diffusion heat treatment at a temperature between 120 and 155C for a time between 2 and 6 hours.
• the friction coating produced according to the invention is a good conductor of heat and electricity, while in addition possessing the unexpected property of providing a friction surface having a low coefficient of friction without unalloyed indium appearing on the surface, which occurs in the above mentioned prior art processes.
• Micrographic examination of a section made in a part of this kind shows the presence of the surface of a layer which is perfectly homogeneous and regular whatever part of the surface is examined, which has perfect adhesion and a hardness between 300 and 450 Vickers under 0.15 N.
• This coating contains copper and indium in the proportion of from 35 to 50 percent by weight of copper in indium, and is composed of hard but nonfragile Cu/ln compounds.
• a bearing treated by the process described in the present invention can operate for several hours with a coefficient of friction of 0.03.
• the aluminium alloy bearing has undergone the treatment of the invention in the following manner:
• the part was thereupon rinsed and then immersed in a galvanic bath to receive a mixed deposition of copper and indium of a thickness of 20 microns; the bath had the composition previously indicated in the description of the invention and the following conditions were adopted:
• alkali metal gluconate in this case potassium gluconate, equal to 2.5 g of this gluconate per gram of indium metal in the bath;
• gluconic acid content equal to 2 mg per litre of bath
• oxalic acid content equal to 1.5 mg per litre of bath
• Second Example This relates to a test of friction between two plane surfaces, carried out under the following experimental conditions: plane cursor ofa length of 20 mm with two longitudinal bearing surfaces ofa width of 4 mm; reciprocating movement on a plane track with a stroke of 60 mm; load: 30 daN; speed of movement 1 cm/s; time delay: 1 second stoppage at the end of each stroke; atmosphere: interposition of grease at beginning and then operation in ambient air without additional supply of lubricant.
• a process for the treatment of the surface of aluminium or an aluminium alloy comprising the steps of a. depositing a copper-indium alloy layer on the said surface by electrolysis in a bath containing, an alkaline solution, monovalent copper ions, trivalent indium ions, an alkali metal hydroxide, an alkali metal cyanide, an alkali metal gluconate, gluconic acid, and oxalic acid, and
• a process according to claim 1. characterised in that the alkali metal gluconate content in the bath is higher than or equal to 0.5 g of this gluconatc per gram of indium metal in the bath.
• a process according to claim 1 characterised in that the heat treatment is effected in air for between 2 and 6 hours.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Electroplating Methods And Accessories (AREA)
• Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
• Electroplating And Plating Baths Therefor (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=9125020

Family Applications (1)

Country Status (13)

Cited By (8)

Families Citing this family (1)

Citations (4)

• 1973
  • 1973-09-14 FR FR7333031A patent/FR2244016B1/fr not_active Expired
• 1974
  • 1974-08-28 SE SE7410901A patent/SE407428B/xx unknown
  • 1974-09-03 NL NL7411651A patent/NL7411651A/xx not_active Application Discontinuation
  • 1974-09-06 ES ES429847A patent/ES429847A1/es not_active Expired
  • 1974-09-09 JP JP10308374A patent/JPS5610992B2/ja not_active Expired
  • 1974-09-09 AR AR255518A patent/AR200366A1/es active
  • 1974-09-09 US US503936A patent/US3891519A/en not_active Expired - Lifetime
  • 1974-09-10 CA CA208,876A patent/CA1030899A/en not_active Expired
  • 1974-09-10 ZA ZA00745762A patent/ZA745762B/xx unknown
  • 1974-09-12 GB GB3988874A patent/GB1443672A/en not_active Expired
  • 1974-09-13 CH CH1248774A patent/CH592747A5/xx not_active IP Right Cessation
  • 1974-09-13 IT IT69776/74A patent/IT1020795B/it active
  • 1974-09-13 BR BR7641/74A patent/BR7407641D0/pt unknown

Patent Citations (4)

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