Classifications

• • 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
  • C25D3/54—Electroplating: Baths therefor from solutions of metals not provided for in groups C25D3/04 - C25D3/50
• • 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
  • C23C26/00—Coating not provided for in groups C23C2/00 - C23C24/00
• • 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
  • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
  • C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
• • 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

Definitions

• This invention is related to a process for producing a surface!
• Said layer consists of manganese (Mn) comprising
• Said layer exhibits a metallurgical bond (fusion bond) to the substrate, i.e. bonding to the substrate by diffusion caused by heating or optionally melting.
• Galvanic (electrolytic) layers characteristically are inferior! to heat bonded layers as regards adherence.
• galvanic (electrolytic) surface layers on j aluminum or aluminum alloy substrates with the same good
• the invention uses a
• the introduction of oxygen and nitrogen in the coating is preferably achieved by heat treating in an atmosphere which supplies nitrogen and oxygen to the manganese layer under the heat treating conditions, preferably an oxidizing treatment in an oxidizing atmosphere, preferably an atmosphere comprising water vapour, preferably for a period of at least 0.5 hours and preferably up to 1.5 hours, and a nitriding treatment, preferably in ammonia or cracked ammonia, preferably for a period of at least 0.5 hours and prefer-ably up to 6 hours.
• oxidizing and nitriding treatments are preferably performed at a temperature of 753 to. 883°K and suitably simultaneously with the previously mentioned heat treatment for bonding the manganese .layer to the substrate.
• the introduction of oxygen, sulphur and ; nitrogen in the coating is preferably achieved by heat j treating in an atmosphere which supplies nitrogen, sulphur and' oxygen to the manganese layer under the heat treating conditions, preferably an atmosphere comprising ammonia (NH_) ! and sulphur dioxide (SO_).
• the introduction of oxygen, sulphur and nitrogen into the manganese layer is preferably performed simultaneously with the previously mentioned heat j treatment.
• ammonia and sulphur dioxide are supplied to the reaction in the gaseous state through separate conduits in order to facilitate and improve the control of the process.
• the quantity of SOun added depends upon the size of the treated articles and is usually from 1.0 to a few per cent, e.g. up to 5% of the ammonia volume.
• the surface coating layer according to the invention comprises in addition to manganese also various compounds of manganese with nitrogen and oxygen, e.g. of the type Mn.N, Mn.,0., etc., as particulate precipitates in the manganese matrix, or various compounds of manganese with nitrogen, oxygen and sulphur, e.g. of the type Mn. (N, S, 0), in which the mutual quantity ratios of N, S and 0 may vary, i.e. from pure Mn,N, and, furthermore, compounds of the types Mn 2 (0,S),, Mn 3 (0,S) ., etc., as particulate precipitates in the manganese matrix.
• the process according to the invention can basically be used for the treatment of all kinds of aluminum and aluminum alloy articles, e.g. parts for internal combustion engines, e.g. spark ignition and diesel engines, e.g. pistons and similar articles, engines with rotating piston, such as wankel engine ⁇ and in general for articles of aluminum and aluminum alloys which are subjected to wear and/or are intended to exhibit low friction.
• the aluminum alloy should preferably have a compo ⁇ sition which permits coating, especially electrolytical coating with manganese (or optionally with manganese alloys consisting mainly or to at least 75% or 90% of manganese) and ; firm bonding of the manganese (or manganese alloy) coating to ; the aluminum substrate by heat bonding (metallurgical bonding) .
• Electrolyte temperature 283-288°K, electrolyte pH 7.0
• the electrolytic manganizing process was performed with anodes made from an alloy of, by weight:
• the aluminum articles were subjected to an oxidizing treatment in water vapour for 0.5 hours and a nitriding treatment in ammonia for 2 hours, both at the temperature 813°K.
• Example 2 The same substrates and pretreatment as in Example 1 were used but instead of the oxidizing-nitriding treatment of Example 1 the aluminum articles were subjected to a heat treatment for introducing oxygen (0), sulphur (S) and nitrogen (N). in an atmosphere comprising a nitrogen source (ammonia, NH.,), a sulphur source and an oxygen source (sulphur dioxide, S0 2 ) at a temperature of 883°K for 3 hours.
• a nitrogen source ammonia, NH.,
• S0 2 oxygen source
• the articles were degreased in the same kind of solution and in the same way as according to Example 1.
• the articles were ⁇ then rinsed in hot and cold water and thereafter immersed into ; a solution of:
• Example 1 The composition of the electrolyte and the treatment conditions were the same as in Example 1.
• the aluminum alloy articles were subjected to an oxidizing treatment in water vapour for 1.5 hours and a nitriding treatment in ammonia (cracked ammonia) for 6 hours, both at a temperature of 753°K.
• the prepared coatings comprise Mn and hard Mn-,0 4 and Mn 4 particles.
• Example 3 The same substrates and pretreatments as in Example 3 were used but instead of the oxidizing and nitriding treatments of Example 3 the aluminum alloy articles were subjected to a heat, treatment in an atmosphere comprising an oxygen source, a sulphur source and a nitrogen source for simultaneous intro ⁇ duction of said elements into the layer, said atmosphere comprising ammonia (NH-,) and sulphur dioxide (SO-) at a temperature of 753°K for 10 hours. Said treatment can be regarded as an oxygen, sulphur and nitrogen saturation treatment. _____,
• the manganese coating according to this invention preferably comprises the compounds or reaction products of manganese with oxygen, nitrogen and optionally sulphur embedded as particles ' in a matrix of manganese metal or alloy, especially as a composite coating.
• the amount of oxygen, nitrogen and optionally sulphur in the coating preferably is an amount corresponding at least to the amount introduced by heat treatment in water vapor or ammonia (or cracked ammoni ⁇ ) or a mixture of ammonia and sulphur dioxide for 0,5 hours at 753°K.
• the manganese coating thickness should be sufficient to give good bonding to the substrate and to form or comprise reaction products of manganese with oxygen and nitrogen or with oxygen, nitrogen and sulfur resp.
• a suitable thickness may be e.g. at least 0,1 micron, preferably at least 0,5 micron , at least 1 micron or at least 5 microns , optionally at least 10 microns, or at least 50 microns.
• a suitable upper thickness limit may be e.g. up to mm, up to 1 mm or up to 0,5 mm or optionally up to 0,1 mm. Also a coating thickness outside said ranges may be used
• the manganese coating may optionally be applied also by e.g. electroless coating, flame spraying or plasma flame spraying deposition from a vapour phase, such as a manganese compound vapor phase , e.g. metallizing with manganese, e.t.c.
• a vapour phase such as a manganese compound vapor phase
• the reaction products with oxygen, nitrogen and optionally sulfur may be included into the manganese coating already in the coating step, e.g. as reaction products formed already prior to the coating step or in the coating step.
• the coating may comprise also other constituents, such as conventional impurities normally present in the raw materials or deliberately added constituents which do not prevent or substantially reduce the desired inventive effect.
• the compsition of the substrate and of the coating are selected so that the coefficient of linear (thermal) expansion match, preferably with a difference in relation to the the aluminum or aluminum alloy substrate of at most 50$, optionally at most 25 % or at most 10.. or even at most 5% within the temperature range of intended use of the coated product.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Mechanical Engineering (AREA)
• Electrochemistry (AREA)
• Other Surface Treatments For Metallic Materials (AREA)
• Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)

Priority Applications (2)

Applications Claiming Priority (4)

Publications (1)

Family

ID=26658789

Family Applications (1)

Country Status (5)

Cited By (3)

Citations (1)

• 1985
  • 1985-09-24 AU AU49641/85A patent/AU4964185A/en not_active Abandoned
  • 1985-09-24 EP EP19850905002 patent/EP0194310A1/en not_active Withdrawn
  • 1985-09-24 WO PCT/SE1985/000367 patent/WO1986001836A1/en not_active Application Discontinuation
• 1986
  • 1986-05-26 FI FI862191A patent/FI862191A0/fi not_active Application Discontinuation
  • 1986-05-26 DK DK245986A patent/DK245986D0/da not_active Application Discontinuation

Patent Citations (1)

Non-Patent Citations (1)

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