Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G1/00—Methods of preparing compounds of metals not covered by subclasses C01B, C01C, C01D, or C01F, in general
  • C01G1/12—Sulfides
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B19/00—Selenium; Tellurium; Compounds thereof
  • C01B19/007—Tellurides or selenides of metals
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D15/00—Electrolytic or electrophoretic production of coatings containing embedded materials, e.g. particles, whiskers, wires
  • C25D15/02—Combined electrolytic and electrophoretic processes with charged materials
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D9/00—Electrolytic coating other than with metals
  • C25D9/04—Electrolytic coating other than with metals with inorganic materials
  • C25D9/08—Electrolytic coating other than with metals with inorganic materials by cathodic processes
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/60—Particles characterised by their size
  • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/60—Particles characterised by their size
  • C01P2004/62—Submicrometer sized, i.e. from 0.1-1 micrometer
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
  • C01P2004/82—Particles consisting of a mixture of two or more inorganic phases two phases having the same anion, e.g. both oxidic phases
  • C01P2004/84—Particles consisting of a mixture of two or more inorganic phases two phases having the same anion, e.g. both oxidic phases one phase coated with the other

Definitions

• ABSTRACT OF THE DISCLOSURE A method of treatment of surfaces, especially metallic surfaces, which is intended to improve their qualities of resistance to friction and wear, said method consisting of subjecting the surface to electrolysis in an aqueous solution of a salt or a mixture of salts, such as the thio or seleno-molybdates, the thio or seleno-tungstates, the thio or seleno niobiates, or of one or more compounds having similar properties, or of a mixture of basic compounds adapted to form said salts in situ.
• a salt or a mixture of salts such as the thio or seleno-molybdates, the thio or seleno-tungstates, the thio or seleno niobiates, or of one or more compounds having similar properties, or of a mixture of basic compounds adapted to form said salts in situ.
• the present invention relates to a method of treatment of surfaces, in particular metallic surfaces, intended to improve their properties of resistance to friction and to wear.
• lamellar compounds with a foliated structure are already known, such as the disulphides of molybdenum M08 tungsten W8 niobium NbS the diselenides of molybdenum MoSe tungsten WSe niobium -NbSe
• the methods at present .known for more or less attaching films of such solid lubricants to mechanical parts are definitely inadequate, and such films do not generally exceed the behaviour in time necessary for a simple running-in.
• the present invention has for its object a method providing a remarkable attachment on a metal surface of a thin film comprising a suitable proportion of lamellar lubricants bound together by a sulphide or a selenide.
• the method according to the invention consists of subjecting the said metallic surface to electrolysis in an appropriate aqueous solution.
• this metallic surface can equally well form part of a solid piece of metal or of a non-metallic part, plastic for example, previously coated by any means with a superficial metallic coating.
• the present invention has also for its object the mechanical parts obtained by this method, which are characterized by friction and wearing qualities having a lasting power unequaled at the present time.
• the part to be treated is immersed in an aqueous solution of a salt or of a mixture of alkali or alkaline-earth salts such as thio or selenio-molybdates, thio or selenio-tungstates, thio or selenio-niobiates, etc.
• a salt or of a mixture of alkali or alkaline-earth salts such as thio or selenio-molybdates, thio or selenio-tungstates, thio or selenio-niobiates, etc.
• the lamellar lubricant incorporated in the film obtained by the method according to the invention is respectively either a disulphide of molybdenum or a diselenide of molybdenum, or a disulphide of tungsten, or a diselenide of tungsten, or a disulphide of niobium, or a diselenide of niobium.
• aqueous solution to be electrolyzed according to the invention with a base of one or more of the substances defined above can be obtained either by directly dissolving the substance or substances, or, as will furthermore be described in a particular example referred to below, by reconstitution in solution of the desired substance or substances.
• the part to be treated is preferably connected to the 3,591,472 Patented July 6, 1971 cathode, that is to say to the negative pole of a direct or rectified source of current, the anode being formed by a piece of conducting material.
• the current density is comprised between 2.5 a./sq. dm. and a./sq. dm.
• these layers are constituted, inter alia, by the solid lubricant corresponding to the electrolyzed substance or substances and the metallic sulphides or selenides corresponding to the base metal.
• EXAMPLE 1 200 grams of thio-molybdate of ammonium having the formula (NH -MoS dissolved in 800 cc. of water constitute the bath, the temperature of which is 35 C.
• the part to be treated is a Faville-Levally test sample for friction, of 16 NC 6 steel, case-hardened, tempered and ground, having the dimensions 6.5 mm. in diameter and 40 mm. in height.
• the anode is constituted by a cylinder concentric with the cathode, having a height of 40 mm. and an internal diameter of 50 mm.
• the current density is 6 a./sq. dm.
• the potential difference between anode and cathode is The period of the treatment is 15 minutes.
• the part is removed from the bath, washed in pure water for 24 hours and brushed with a metal brush.
• the part according to the invention is covered with a fine grey film having a thickness of 2 microns. It is then rotated between two jaws, in conformity with those of the Faville-Levally test, of 16 NC 6 casehardened and tempered, untreated.
• the test on the Faville-Levally machine lasted 6 minutes with a load of 15,000 N for a speed of rotation of the sample of 350 rpm. with an average coeflicient of friction in the dry state, of 0.04.
• test sample of 16 NC 6 casehardened, tempered and coated with molybdenum disulphide by methods at present known washed for two hours and then brushed with a metal brush, seizes under a load of 4,000 N after a few seconds of test.
• EXAMPLE 2 The solution following the present example of the invention is obtained, not by starting with the basic substance, but by a suitable mixture of various substances capable of resulting in the re-constitution of the substance of Example 1.
• a mixture of this kind has a pH value of 10.3 at a temperature of 35 C.
• the pH value falls to 9.1 and the pH value is readjusted by adding the mixture of molybdenum oxide and ammonia so as to maintain it at the value of 10.5.
• EXAMPLE 3 The bath and the electrolytic parameters are identical with those of Example 2.
• the part to be treated is a Faville-Levally test sample of stainless steel Z3 CN 18-8.
• the temperature of the bath is 53 C.
• the electrolytic parameters are 20 minutes a./sq. dm.
• the sample After treatment, the sample is washed with running Water for two hours and then brushed with a metal brush.
• the duration of the Faville-Levally test of such a treated sample, rotating between two jaws, also of Z3 CN 188 steel is 1 minute 30 seconds under a load of 8,000 N, with a coetficient of friction which does not exceed 0.05.
• EXAMPLE 4 The bath is composed at the start of 100 grams of tungsten oxide W0 and 700 cc. of 20% ammonia NH OH. After dissolving the oxide in the ammonia, sul phuretted hydrogen H 5 is bubbled into the bath in order to produce ammonium thio-tungstate.
• the temperature of the solution is comprised between and 70 C.; the pH value of the solution at a temperature of C. is comprised between 7 and 8.5.
• the electrolytic parameters are as follows: a./sq. dm. for 30 minutes.
• the Faville friction test of a test sample of this kind of 16 NC 6, case-hardened and tempered, treated as described above, rotating between jaws of 16 NC 6 casehardened and tempered but not treated, has a duration of 2 minutes at a load of 20,000 daN and a speed of slip of 0.075 m./sec. with a coefficient of friction which does not exceed 0.06.
• EXAMPLE 5 The bath has a composition identical with that given in Example 2. Its temperature is 43 C. and its pH value at that temperature is 10.8.
• test sample to be treated is an annealed alloy of titanium TA 6V; the anode is identical with that given in Example 1.
• the electrolytic parameters are: 10 minutes- 10 a./sq. drn.
• test sample is washed in running water for 2 hours and brushed with a metal brush, and if this test sample is subjected to the Faville- Levally test between two jaws cut to a V, of titanium TA 6V annealed but not treated, the duration of the test is 2 minutes at a load of 2,500 N with an average coefiicient of friction which does not exceed 0.05.
• a method of treating an electrically conductive surface to improve the resistance to friction and wear comprising subjecting said surface to electrolysis as the cathode in an aqueous solution of a salt selected from the group consisting of the thio-molybdates, thiotungstates, and thio-niobiates of ammonium.
• a method of treating an electrically conductive surface to improve the resistance to friction and wear comprising subjecting said surface to electrolysis as the cathode in an aqueous solution of a salt selected from the group consisting of the seleno-molybdates, seleno-tungstates, and seleno-niobiates of ammonium.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Lubricants (AREA)
• Electroplating And Plating Baths Therefor (AREA)
• Chemical Treatment Of Metals (AREA)
• Electrochemical Coating By Surface Reaction (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=8636458

Family Applications (1)

Country Status (12)

Cited By (4)

Families Citing this family (2)

• 0
  • GB GB1227452D patent/GB1227452A/en not_active Expired
• 1967
  • 1967-08-07 FR FR117007A patent/FR1541726A/fr not_active Expired
• 1968
  • 1968-07-29 BE BE718732D patent/BE718732A/xx unknown
  • 1968-07-29 CH CH1133468A patent/CH487258A/fr not_active IP Right Cessation
  • 1968-08-01 US US749318A patent/US3591472A/en not_active Expired - Lifetime
  • 1968-08-03 ES ES356893A patent/ES356893A1/es not_active Expired
  • 1968-08-05 LU LU56642D patent/LU56642A1/xx unknown
  • 1968-08-06 CS CS5693A patent/CS150961B2/cs unknown
  • 1968-08-06 PL PL1968128526A patent/PL80345B1/pl unknown
  • 1968-08-07 JP JP43055568A patent/JPS4823774B1/ja active Pending
  • 1968-08-07 NL NL6811235A patent/NL6811235A/xx not_active Application Discontinuation
  • 1968-08-07 DE DE1771955A patent/DE1771955C3/de not_active Expired

Also Published As

Similar Documents