US20170121841A1 - Electroceramic Coating for Magnesium Alloys - Google Patents

Electroceramic Coating for Magnesium Alloys Download PDF

Info

Publication number
US20170121841A1
US20170121841A1 US15/405,774 US201715405774A US2017121841A1 US 20170121841 A1 US20170121841 A1 US 20170121841A1 US 201715405774 A US201715405774 A US 201715405774A US 2017121841 A1 US2017121841 A1 US 2017121841A1
Authority
US
United States
Prior art keywords
inorganic
layer
based coating
magnesium
sub
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.)
Abandoned
Application number
US15/405,774
Other languages
English (en)
Inventor
Shawn E. Dolan
Kirk Kramer
Lisa K. Salet
Michael A. Murphy, Jr.
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.)
Henkel AG and Co KGaA
Original Assignee
Henkel AG and Co KGaA
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 Henkel AG and Co KGaA filed Critical Henkel AG and Co KGaA
Publication of US20170121841A1 publication Critical patent/US20170121841A1/en
Assigned to HENKEL AG & CO. KGAA reassignment HENKEL AG & CO. KGAA ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KRAMER, KIRK, MURPHY, MICHAEL A., JR., SALET, LISA K., DOLAN, SHAWN E.
Abandoned legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/30—Anodisation of magnesium or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/022—Anodisation on selected surface areas
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/024—Anodisation under pulsed or modulated current or potential
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/026—Anodisation with spark discharge

Definitions

  • This invention relates to articles having magnesium-containing metal surfaces with an electroceramic coating chemically bonded to the metal surfaces and to articles having a composite coating comprising first sectors of electroceramic coating and second sectors comprising organic and/or inorganic components different from the electroceramic coating.
  • the invention further relates to processes of making and using the articles.
  • the light weight ( ⁇ 1.74 gm/cm 3 density) and strength of magnesium and magnesium alloys makes products fashioned therefrom highly desirable for use in manufacturing parts, for example, electronic devices, including handheld electronic devices; motor vehicles; aircraft and other products where low density is beneficial.
  • magnesium and magnesium alloys One of the most significant disadvantages of magnesium and magnesium alloys is susceptibility to corrosion. Exposure to oxygen, moisture and other environmental agents, such as human fingerprint constituents, causes magnesium and magnesium alloy surfaces to corrode. This corrosion is both unsightly and reduces strength.
  • Anodization One method used to improve corrosion resistance of metal surfaces is anodization, see for example U.S. Pat. No. 4,978,432, U.S. Pat. No. 4,978,432 and U.S. Pat. No. 5,264,113.
  • a metal (M) surface is electrochemically oxidized to form metal oxides (MOx) from the metal surface thereby creating a coating layer.
  • MOx metal oxides
  • anodization of magnesium and magnesium alloys generating MgO affords some protection against corrosion, improvements in corrosion performance are desirable.
  • conventional anodization often fails to form a protective layer on the entire surface of a complex workpiece. Anodized coatings have been found to contain cracks, some down to the metal surface, at sharp corners. Further, adhesion of paint to anodized magnesium surfaces is often insufficient and improvements are needed.
  • Plasma Electrolytic Oxidation also known as Micro Arc Oxidation (MAO), Spark Anodizing and Microplasma Oxidation, referred to herein collectively as “PEO”
  • PEO Plasma Electrolytic Oxidation
  • MAO Micro Arc Oxidation
  • Spark Anodizing Spark Anodizing and Microplasma Oxidation
  • PEO Plasma Electrolytic Oxidation
  • MAO Micro Arc Oxidation
  • Spark Anodizing and Microplasma Oxidation referred to herein collectively as “PEO”
  • PEO Plasma Electrolytic Oxidation
  • MAO Micro Arc Oxidation
  • Spark Anodizing Spark Anodizing
  • Microplasma Oxidation referred to herein collectively as “PEO”
  • PEO Plasma Electrolytic Oxidation
  • MAO Micro Arc Oxidation
  • Spark Anodizing Spark Anodizing
  • Microplasma Oxidation referred to herein collectively as “PEO”
  • PEO processing of magnesium and its alloys oxidizes the magnesium producing a coating that contains crystalline magnesium oxide (60-80 vol. %) with minor amounts of magnesium silicate and/or magnesium phosphate, depending on the content of the PEO bath.
  • PEO processes have disadvantages including weaker throwing power that can result in thin coatings on inner or less accessible surface areas of the substrate. Due to the voltage and amperage required to generate the “glow” or “sparking” needed for PEO, the process has electricity consumption greater than processes which do not require micro-arc discharges.
  • the resulting oxide layer produced using PEO consists of two sub-layers, the outer layer is a brittle sub-layer with a porosity of more than 15%, which is removed by an additional polishing step. Removal of the outer layer has the disadvantages of additional processing and, often, manual labor, as well as loss of dimensional integrity of the article and challenges in uniformly polishing complex articles or those having non-uniform coating layers due to throw-power limitations of PEO.
  • % Zn has three main phases namely primary ⁇ (i.e. matrix), eutectic ⁇ (i.e. Al-rich ⁇ ) and ⁇ phase (Mg17A112 intermetallic), since the substrate is electrochemically heterogeneous each constituent reacts differently in the an electrolytic coating bath leading to non-uniform coating growth which tends to degrade the corrosion resistance of coatings.
  • primary ⁇ i.e. matrix
  • eutectic ⁇ i.e. Al-rich ⁇
  • ⁇ phase Mg17A112 intermetallic
  • the metal content and surface contamination of industrial grade magnesium alloys varies considerably based on alloy type, raw material and production conditions, and even the vendor. Many of these variables are outside the control of the product manufacturer and lead to variation in coating uniformity and reduced corrosion resistance. It is desirable to provide a process for uniformly coating Mg alloys and coated Mg alloy articles with improved corrosion resistance.
  • the inorganic-based coating may have additional layers deposited thereon, may form a composite coating comprising the inorganic-based coating and a second component distributed throughout at least a portion of the inorganic-based coating and/or the coating on the magnesium containing article may comprise a reaction product the inorganic-based coating and a second component.
  • first sub-layer O wt. % ⁇ second sub-layer O wt. %.
  • step F) i) is present and comprises a step of introducing at least one vanadium containing composition as the second component to the second sub-layer of inorganic-based coating, contacting at least the external surfaces and desirably at least some of the internal surfaces of the second sub-layer, whereby the second component forms a thin film in contact with the external surfaces of the inorganic-based coating and lining at least a portion of the pores in the inorganic-based coating.
  • the infusing step comprises reacting the vanadium containing composition and elements of the inorganic-based coating to thereby form a portion of the second component, which is different from the inorganic-based coating and the vanadium containing composition.
  • step F) ii) is present and comprises contacting the first layer of an inorganic-based coating with a polymeric composition thereby forming a second layer comprising organic polymer chains and/or inorganic polymer chains; and optionally applying a layer of paint after the post-treating step.
  • a magnesium-containing article comprising at least one metallic magnesium or magnesium alloy surface coated according to the methods disclosed herein.
  • a magnesium-containing article comprising at least one metallic magnesium or magnesium alloy surface coated with a first layer of an inorganic-based coating chemically bonded directly to said surface wherein the inorganic-based coating has a bilayer structure.
  • the bilayer structure may comprise: a first sub-layer directly bonded to the bare metallic magnesium or magnesium alloy surface at a first interface, said first sub-layer comprising at least 70 wt. % of a combined mass of fluorine and magnesium, and a positive amount of oxygen present in an average amount of less than about 20 wt.
  • It is also an object of the invention to provide a magnesium-containing article having a composite coating comprising: a matrix formed by a first layer of an inorganic-based coating chemically bound directly to at least one metallic magnesium or magnesium alloy surface, said matrix having pores and internal surfaces defined by pores, at least some of said pores being in communication with an external surface of the first layer and forming openings therein; and a second component, different from the inorganic-based coating, distributed throughout at least a portion of the matrix comprising the pores, said second component being in contact with at least some of the internal surfaces and external surfaces.
  • the article may further comprise a second layer that is different from the inorganic-based coating and is adhered to at least external surfaces of the inorganic-based coating.
  • FIG. 1 is an electron micrograph of a cross-section of a panel of AZ-31 coated according to Example 1, prior to post-treating, at 2500 ⁇ magnification.
  • the line with white arrows indicates a distance of 3.08 micron between the end points.
  • FIG. 2 is a graph of elemental composition, in weight percent, of an inorganic-based electrolytically deposited coating according to the invention showing varying chemical composition of a coating of the invention, as a function of distance from the magnesium alloy surface.
  • Articles according to the invention include magnesium-containing articles having a coating, which may be an electrolytically deposited coating, chemically bonded to one or more metal surfaces of the magnesium-containing article. Such articles are useful as for example, parts for motor vehicles, aircraft, and electronic devices, including handheld electronic devices, and other products where the light weight and strength of magnesium is desired.
  • the articles generally have at least one metal surface, which comprises magnesium metal, and chemically bonded directly to that surface an inorganic-based coating.
  • the inorganic-based coating is post treated to improve corrosion resistance.
  • magnesium-containing article means an article having at least one surface that may be in whole or in part metallic magnesium or a magnesium alloy.
  • the body of the article may be formed of metallic magnesium or a magnesium alloy or may be formed of other materials, e.g. metals other than magnesium, polymeric materials, refractory materials, such as ceramics, that have a layer of magnesium or magnesium alloy on at least one surface.
  • the other materials may be other metals different from magnesium, non-metallic materials or combinations thereof, such as composites or assemblies.
  • the article may comprise at least one surface of metallic magnesium or a magnesium alloy comprising, in order of increasing preference, at least about 51, 60, 65, 70, 75, 80, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 wt. % magnesium.
  • Chemically bonded to at least one magnesium surface of the magnesium-containing article is a first layer comprising an inorganic-based coating.
  • An inorganic-based coating may include some organic material, but contains a greater mass of inorganic material than of organic molecules.
  • the inorganic material may act as a matrix in which any organic constituent may be distributed.
  • the inorganic-based coating may be applied by an electrolytic deposition process as described herein.
  • the inorganic-based coating contains magnesium, fluorine, oxygen, at least one alloying element from the Mg substrate and at least one metal from the bath.
  • the inorganic-based coating may comprise carbon. Both the carbon and alloying elements, if present, may be dispersed in an insulating ceramic layer. Even with inclusion of carbon and alloying elements in the inorganic-based coating, a uniform thickness is generated which provides uniform paint and adhesive bonding, as well as corrosion resistance, which is improved as compared to the bare surface of the magnesium containing substrate. This feature of the invention is beneficial in reducing scrap rate where substrates and the inorganic-based coatings deposited thereon achieve good coating quality even in the presence of carbon and alloying elements in the inorganic-based coating.
  • the inorganic-based coating comprises C, O, F, Al, Mg, and alkali metal. Desirably the alkali metal comprises less than 50, 40, 30, 20, 10, 5 or 1% Na.
  • the inorganic-based coating comprises magnesium, which may be present in a total amount ranging from, in order of increasing preference, at least about 10, 12, 14, 16, 18, or 20 atomic % and in order of increasing preference, not more than 45, 40, 35, 33, 30, 28, 26, 24 or 22 atomic %.
  • the inorganic-based coating comprises fluorine, which may be present in a total amount ranging from, in order of increasing preference, at least about 15, 20, 22, 24, 26, 28, 30, 32, 34, 36, or 38 atomic % and in order of increasing preference, not more than 60, 55, 50, 45 or 40 atomic %.
  • the inorganic-based coating comprises oxygen, which may be present in a total amount ranging from, in order of increasing preference, at least about 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, or 20 atomic % and in order of increasing preference, not more than 33, 30, 28, 26, 24 or 22 atomic %.
  • the inorganic-based coating may comprise carbon, which may be present in a total amount ranging from, in order of increasing preference, at least about 3, 4, 5, 6, 7, 8, 9, 10 atomic % and in order of increasing preference, not more than 33, 30, 28, 26, 14 or 12 atomic %.
  • the inorganic-based coating may comprise alloying metals from the magnesium-containing article; alkaline earth metals, different from magnesium; and/or alkali metals, which may be present in a total amount ranging from, in order of increasing preference, at least about 1, 2, 3, 4, or 5 atomic % and in order of increasing preference, not more than 14, 13, 12, 10, 8 or 6 atomic %.
  • more than 50 wt. % of the total amount of these constituents present in the inorganic-based coating may be localized near the external surface of the inorganic-based coating, meaning the inorganic-based coating surface that is not in direct contact with a metallic surface of the magnesium-containing article.
  • the inorganic-based coating may comprise fluorine and magnesium in atomic ratios of fluorine to magnesium of about 0.25:1, 0.3:1, 0.4:1, 0.5:1, 0.75:1, 1:1, 1.25: 1, 1.5:1, 1.75:1, 2:1, 2.25:1, 2:5, 2.75:1, 3;1, 3.25:1, 3.5:1, or 3.75;1.
  • the ratio of oxygen to fluorine in the inorganic-based coating may exhibit a gradient wherein amount of oxygen relative to amount of fluorine increases as a function of distance from the magnesium-containing article's metal surface. In one embodiment, the ratio may range from about 0.1:1 up to about 1:1.
  • the inorganic-based coating may have a bi-layer morphology, as shown in FIG. 1 and FIG. 2 .
  • FIG. 1 shows an electron micrograph of a cross-section of a magnesium alloy panel coated according to Example 1, prior to application of a post-treatment, at 2500 ⁇ magnification.
  • the inorganic-based coating has a bilayer structure, despite being deposited in a single processing step: a first sub-layer 1 directly bonded to the metal surface 2 and having an interface 5 with the metal surface (first interface); and a second sub-layer 3 in direct contact with the first sub-layer and spaced away from the metal surface by the first sub-layer lying there between.
  • the second sub-layer is directly bonded with the first sub-layer at an interface 6 with the first sub-layer (second interface).
  • the second sub-layer of the inorganic-based coating comprises pores 4 , and has internal surfaces 7 and external surfaces 8 .
  • the internal surfaces are defined by pores in the second sub-layer and lie interior to the outer boundary 9 of the inorganic-based coating, which comprises the external surfaces of the second sub-layer.
  • the white arrowed line in FIG. 1 extending from the metal surface to the outer boundary of the inorganic-based coating, represents a thickness of about 3 microns for the inorganic-based coating.
  • the external surfaces of the second sub-layer lie in a boundary between inorganic-based coating and an external environment or a secondary layer applied to the outer boundary and are not in direct contact with a metallic surface of the magnesium-containing article.
  • the first sub-layer may have few or no pores and has a more dense composition than the second sub-layer. Any pores present in the first sub-layer are desirably not contiguous between the metallic surface of the article and the external surface of the inorganic-based coating layer, and optionally smaller than the pores of the second sub-layer. Some of the pores of the second sub-layer are open pores in communication with the external surface.
  • the second sub-layer may comprise open and closed cell pore structure.
  • Pore size may range from about 0.1 microns to 5 microns and may make up as much as 50% or more of the volume of the deposited coating.
  • the electrolytically applied inorganic-based coating may have a surface area that is about 75 -150 ⁇ that of the uncoated substrate surface.
  • FIG. 2 is a graph of an elemental depth profile taken of inorganic-based coatings according to the invention using glow discharge optical emission spectroscopy (GDOES). Amounts of various elements are shown in weight percent at particular distances from the metal surface.
  • FIGS. 1 and 2 show that the first sub-layer and the second sub-layer are different in morphology and elemental content. Composition of the first sub-layer may vary somewhat depending upon the Mg alloy used, and may comprise 50, 60, 70, 80 or 90 wt. % of a combined mass of fluorine and magnesium, and may additionally comprise about 1 to about 20 wt. % oxygen.
  • GDOES glow discharge optical emission spectroscopy
  • the second sub-layer may have a weight percent of fluorine that is less than the weight percent of fluorine found in the first sub-layer; the second sub-layer may have a weight percent of Mg that is less than the weight percent of Mg found in the first sub-layer; and the second sub-layer may have a weight percent of oxygen that is greater than the weight percent of oxygen found in the first sub-layer.
  • the inorganic-based coating has an amorphous structure.
  • Physical morphology of the inorganic-based coating may comprise non-crystalline compounds of magnesium and one or more of elements.
  • the inorganic-based coating shows amorphous structure by X-ray crystallography (XRD).
  • the inorganic-based coating may be a hard (Vickers 400-900 by nanoindentation), amorphous coating comprising non-stoichiometric magnesium compounds.
  • Nonstoichiometric glasses of Mg and F, with or without oxygen may be present.
  • the inorganic-based coating is an inorganic composition comprising Mg, O & F, including stoichiometric and non-stoichiometric compounds of said elements with each other.
  • the inorganic composition comprises crystalline and non-crystalline compounds comprising magnesium, with more than 50 atomic percent of the composition comprising non-crystalline compounds.
  • Coating thickness of the inorganic-based electrolytically deposited coating may range from 0.1 microns to about 50 microns, desirably 1-20 microns depending upon the desired use of the coated article. Coating thickness of the inorganic-based electrolytically deposited coating desirably is at least, in increasing order of preference 0.5, 1, 3, 5, 7, 9, 10 or 11 microns thick, and no more than, if only for economic reasons, in increasing order of preference, 50, 30, 25, 20, 15, 14, 13, or 12 microns thick. As a decorative layer, the coating may range from 2-5 microns. In one embodiment, the coating thickness ranges from 3 to 8.5 microns.
  • electrolytically applied inorganic-based coatings according to the invention perform better than commercially available conversion coatings for magnesium in unpainted and painted corrosion testing, as well as providing improved corrosion resistance when compared to PEO coatings on magnesium alloys typically used in the automotive industry, e.g. magnesium casting alloys and forged alloys.
  • the electrolytically applied inorganic-based coatings perform better than commercially available conversion coatings for magnesium in unpainted and painted corrosion testing, as well as providing improved corrosion resistance when compared to PEO coatings on magnesium alloys typically used in the automotive industry, e.g. magnesium casting alloys and forged alloys.
  • magnesium-containing article may have a composite coating wherein the inorganic-based coating may act as a matrix.
  • This embodiment may include a coating comprising:
  • the coating on the magnesium containing article may comprise:
  • the second component may have the same composition as the second layer. In another embodiment of the invention, the second component may be different from both A) and C). In one embodiment, the second component and/or the second layer may form reaction products with elements in the inorganic-based coating. In one embodiment, the inorganic-based coating has a layer of paint deposited thereon, which may comprise the second layer or may be in addition to the second layer.
  • inorganic-based coatings according to the invention and aqueous compositions for depositing the inorganic-based coatings, as defined above, may be substantially free from many ingredients used in compositions for similar purposes in the prior art.
  • aqueous compositions according to the invention when directly contacted with metal in a process according to this invention, contain no more than 1.0, 0.5, 0.35, 0.10, 0.08, 0.04, 0.02, 0.01, 0.001, or 0.0002 percent, more preferably said numerical values in grams per liter, of each of the following constituents: chromium, cyanide, nitrite ions; organic materials, e.g. organic surfactants; amines, e.g. hydroxylamines; ammonia and ammonium cations; silicon, e.g.
  • sulfur e.g. sulfate; permanganate; perchlorate; borate and/or free chloride.
  • as-deposited inorganic-based coatings and inorganic secondary layers according to the invention contain no more than 1.0, 0.5, 0.35, 0.10, 0.08, 0.04, 0.02, 0.01, 0.001, or 0.0002 percent, more preferably said numerical values in parts per thousand (ppt), of each of the following constituents: chromium, cyanide, nitrite ions; organic materials, e.g.
  • organic surfactants amines, e.g. hydroxylamines; ammonia and ammonium cations; silicon, e.g. siloxanes, organosiloxanes, silanes, silicate; phosphorus; rare earth metals; sodium; sulfur, e.g. sulfate; permanganate; perchlorate; borate and/or free chloride.
  • Inorganic-based coatings can be produced by a variety of processes capable of generating hard, amorphous coatings chemically bonded to magnesium-containing metals.
  • the inorganic-based coating may be formed using electrolytic deposition according to the inventive process described herein.
  • Processes according to the invention are directed to methods of improving corrosion resistance on magnesium containing substrates comprising:
  • the process may comprise optional steps of: cleaning, etching, deoxidizing and desmutting with or without intervening steps of rinsing with water.
  • a rinse water may be counterflowed into a preceding bath.
  • a step 5) of masking or closing off portions of the article to limit or prevent contact with the electrolyte may be performed prior to contacting the magnesium containing article with the electrolyte.
  • masking may be applied to magnesium containing portions of the article where no coating is desired or may be applied to protect article components or surfaces that might be damaged by the electrolyte, likewise hollow portions of an article, e.g. the lumen of a pipe, may be closed off or plugged to prevent electrolyte contact of interior surfaces.
  • the inorganic-based coating is not physically or chemically removed or etched. Specifically, no more than 1000, 500, 100, 50, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 or 0.5 mg/m2 of the inorganic-based coating may be removed from the article. Preferably none of the deposited inorganic-based coating is removed.
  • the surface to be electrolytically coated has sufficient magnesium metal or other light metal in combination with magnesium, desirably in the zero oxidation state, to permit coating generation and the non-magnesiferous surfaces are not negatively affected by the treatments.
  • Masking of selected surfaces to prevent contact with electrolyte can be accomplished by methods known in the art.
  • the electrolytic treatment is advantageously applicable to magnesium-base alloys containing one or more other elements such as Al, Zn, Mn, Zr, Si and rare earth metals.
  • the magnesium containing surfaces to be coated are contacted with an electrolyte, desirably an aqueous electrolyte comprising dissolved fluoride ions and free of phosphorus.
  • the electrolyte may have a pH of 10 or more, desirably greater than 10, 11, 12 or 13.
  • an electrolyte is employed which may be maintained at a temperature between about 5° C. and about 90° C., desirably from about 20° to about 45° C.
  • a magnesium or magnesium alloy surface is contacted with, desirably immersed in, an aqueous electrolyte and electrolyzed as the anode in the circuit.
  • One such process comprises immersing at least a portion of the article in the electrolyte, which is preferably contained within a bath, tank or other such container.
  • a second article that is cathodic relative to the anode is also placed in the electrolyte.
  • the electrolyte is placed in a container which is itself cathodic relative to the article (anode).
  • Voltage is applied across the anode and cathode for a time sufficient to form an inorganic-based electrolytic coating.
  • the time required to produce a coating in an electrolytic process according to the invention may range, in increasing order of preference, from about 30, 60, 90, 120 seconds, up to about 150, 180, 210, 240, 300 seconds. Longer deposition times may be utilized but are considered commercially undesirable.
  • Electrolytic processing time can be varied to maximize efficiency by reducing time to Vmax and to control coating weight.
  • Alternating current, direct current or a combination may be used to apply the desired voltage, e.g. straight DC, pulsed DC, AC waveforms or combinations thereof.
  • pulsed DC current is used.
  • a period of at least 0.1, 0.5, 1.0, 3.0, 5.0, 7.0, 9.0, or 10 millisecond and not more than 50, 45, 40, 35, 30, 25, 20, or 15 millisecond may be used, which period may be held constant or may be varied during the immersion period.
  • Waveforms may be rectangular, including square; sinusoidal; triangular, sawtooth; and combinations thereof, such as by way of non-limiting example a modified rectangle having at least one vertical leg that is not perpendicular to the horizontal portion of the rectangular wave.
  • Peak voltage potential desirably may be, in increasing order of preference, up to about 800, 700, 600, 500, 400 volts, and may desirably is at least in increasing order of preference 140, 150, 160, 170, 180, 200, 300 volts. In one embodiment peak voltage can range from 120-200 volts.
  • Average voltage may be in increasing order of preference at least 50, 70, 90, 100, 120, 130, 140, or 150 volts and independently preferably may be less than 600, 550, 500, 450, 400, 350, 300, 250, 200 or 180 volts. In one embodiment, average voltage can range from about 120-300 volts. In another embodiment, average voltage may be selected to be in a higher range of 310-500 volts.
  • Voltage is applied across the electrodes until a coating of the desired thickness is formed on the surface of the article. Generally, higher voltages result in increased overall coating thickness and sparking may ensue. Higher voltages may be used within the scope of the invention provided that the substrate is not damaged and coating formation is not negatively affected.
  • the electrolyte for the process may be an aqueous alkaline composition comprising a source of fluorine and a source of hydroxide ions.
  • the source of hydroxide may be inorganic or organic, provided that it can be dissolved or dispersed in the aqueous electrolyte and does not interfere with the deposition of the inorganic-based coating. Suitable examples include NaOH and KOH, with KOH being preferred.
  • the source of fluoride may be inorganic or organic, provided that it can be dissolved or dispersed in the aqueous electrolyte and does not interfere with the deposition of the inorganic-based coating.
  • Suitable examples include at least one of alkali metal fluorides, certain alkaline earth metal fluorides and ammonium bifluoride.
  • the electrolyte may comprise KF and KOH.
  • free alkalinity is measured and maintained at approximately 10-25 ml titrant using the following alkalinity titration: Pipet 50 mls (volumetric pipet) of bath into a beaker and titrate with phenolphthalein indicator until a clear endpoint is reached using 0.10 M HCl titrant.
  • the process alkalinity is controlled to be at least in order of increasing preference 7, 8, 9,10, 11, 12, 13, or 14 ml and is not more than 24, 23, 22, 21, 20, 19, 18, 17, 16 or 15 ml.
  • the above-described coating process provides improved energy efficiency by lower electrical consumption compared to PEO/MAO processes.
  • the inventive process generally requires less than 20%, 15% or 10% of the electricity consumption (in kWh) to apply an electroceramic coating equal in thickness to a PEO coating per unit surface area.
  • the inventive process utilizes in increasing order of preference, no more than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1.5, 1 kWh/m 2 and energy consumption may be as low as in increasing order of preference 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 kWh/m 2 .
  • the electroceramic coating process also has lower cooling requirements for the electrolyte compared to PEO/MAO, generally less than 20%, 15% or 10% cooling of the electrolyte needed, which is in part due to the lack of spark generation.
  • magnesium-containing surfaces Prior to electrolytic coating, magnesium-containing surfaces may be subjected to one or more of cleaning, etching, deoxidizing and desmutting steps, with or without rinsing steps. Cleaning may be alkaline cleaning and a cleaner may be used to etch the surfaces. A suitable cleaner for this purpose is Parco Cleaner 305, an alkaline cleaner commercially available from Henkel Corporation. Desirably, the magnesium-containing surfaces may be etched by at least in increasing order of preference 1, 3, 5, 7, 10, or 15 g/m2 and independently preferably, at least for economy, not more than 20, 25, 30, 35, 40, 45 or 50 g/m2. Etching can be accomplished using commercially available etchants and/or deoxidizers for magnesium.
  • a desmutting step may also be included in processing.
  • Suitable desmutters include acids such as carboxylic acids, e.g. hydroxyacetic acid, alone or in combination with chelators and nitrates. If any of the above-described steps is utilized, the magnesium-containing surfaces are typically rinsed as a final step to reduce introduction of the prior steps' chemistries into the electrolyte.
  • Additional processing steps may be used after deposition of the inorganic-based coating, such as rinsing with water, alkaline solutions, acid solutions and combinations of such steps.
  • the process may include steps of applying at least one post-treatment, which may be dispersed in the inorganic-based coating, may form reaction products therewith, and/or may form an additional layer and combinations thereof.
  • the additional layer may be an inorganic layer, an organic layer or a layer that comprises inorganic and organic components.
  • any post-treatments including for example additional layers described herein, are durably bound to the inorganic-based coating; while other removable layers for masking during manufacture or for shipping after coating may be applied.
  • the porous structure of the electrolytically deposited inorganic-based coatings on the magnesium containing article was a particular challenge for post-treatments that are not pore closing due to the significant surface area present on the internal surfaces of inorganic-based coatings.
  • Surface area of inorganic-based coatings according to the invention is generally 75 to 100 times that of the original metal surface, by BET measurement. Such surface area is typically not found in conventional conversion coatings, such as for example oxide coatings of Zr, Ti, Co, and the like.
  • a vanadium-containing post-treatment step was surprisingly found to be a suitable method for introducing a second component for additional corrosion protection, in processes according to the invention, despite other post-treatments useful for anodized layers having little or no positive effect on corrosion resistance.
  • Vanadium can be present in the post-treatment in various oxidation states such as III, IV, and V.
  • Sources of vanadium ions in the post-treatment can include metallic V, organic and inorganic V-containing materials, for example V-containing minerals and compounds.
  • Suitable compounds of V include by way of non-limiting example oxides, acids and their salts, and V- containing organic materials, e.g.
  • decavanadate salts have been characterized: NH 4+ , Ca 2+ , Ba 2+ , Sr 2+ , and group I decavanadate salts may be prepared by the acid-base reaction between V 2 O 5 and the oxide, hydroxide, carbonate, or hydrogen carbonate of the desired positive ion.
  • Suitable decavanadate post-treatments include: Vanadium acetyl acetonate, (NH 4 ) 6 [V 10 O 28 ].6H 2 O, K 6 [V 10 O 28 ].9H 2 O, K 6 [V 10 O 28 ].10H 2 O, Ca 3 [V 10 28 .16H 2 O, K 2 Mg 2 [V 10 O 28 ].16H 2 O, K 2 Zn 2 [V 10 O 28 ].16H 2 O, Cs 2 Mg 2 [V 10 O 28 .16H 2 O, Cs 4 Na 2 [V 10 O 28 ].10H 2 O, K 4 Na 2 [V 10 O 28 ].16H 2 O, Sr 3 [V 10 O 28 ].22H 2 O, Ba 3 [V 10 O 28 ].19H 2 O, [(C 6 H 5 ) 4 P]H 3 V 10 O 28 .4CH 3 CN and sodium ammonium decavanadate (nominally (NH 4 ) 4 Na 2 [V 10 O 28 ]).
  • Suitable vanadium containing compositions according to this invention comprise, consist essentially of, or preferably consist of, water and vanadate ions, particularly decavanadate ions.
  • concentration of vanadium atoms present in vanadate ions in the composition according to this invention preferably is, with increasing preference in the order given, at least 0.0005, 0.001, 0.002, 0.004, 0.007, 0.012, 0.020, 0.030, 0.040, 0.050, 0.055, 0.060, 0.065, 0.068, 0.070, or 0.071 M and independently preferably is, with increasing preference in the order given, primarily for reasons of economy, not more than 1.0, 0.5, 0.30, 0.20, 0.15, 0.12, 0.10, 0.090, 0.080, 0.077, 0.074, or 0.072 M.
  • the temperature of such a post-treating composition, during contact with the inorganic-based coating on the magnesium containing article as described above preferably is, with increasing preference in the order given, at least 30° C., 35° C., 40° C., 45° C., 48° C., 51° C., 53° C., 55° C., 56° C., 57° C., 58° C. or 59° C. and independently preferably is, with increasing preference in the order given, not more than 90° C., 80° C., 75° C., 72° C., 69° C., 67° C., 65° C., 63° C., 62° C. or 61° C.
  • the time of contact between the vanadium containing composition and the inorganic-based coating on the magnesium containing article as described above preferably is, with increasing preference in the order given, not less than 0.5, 1.0, 2.0, 2.5, 3.0, 3.5, 4.0, 4.3, 4.6, or 4.9 min and independently preferably is, with increasing preference in the order given, primarily for reasons of economy, not greater than 60, 30, 15, 12, 10, 8, 7.0, 6.5, 6.0, 5.7, 5.4, or 5.1 min.
  • At least one vanadium containing composition is desirably introduced to the second sub-layer of inorganic-based coating, contacting at least the external surfaces and desirably at least some of the internal surfaces thereof.
  • the second component may comprise the vanadium containing composition and/or may comprise reaction products of the vanadium containing composition and elements of the inorganic-based coating.
  • the vanadium containing composition reacts with elements of the inorganic-based coating to thereby form a second component, which is different from the inorganic-based coating at least in that the second component comprises vanadium.
  • the second component may form a thin film in contact with the external surfaces of the inorganic-based coating and lining at least a portion of the pores in the inorganic-based coating.
  • the vanadium containing compositions may also contact internal surfaces of the inorganic-based coating and/or react with elements of the internal surfaces rendering the inorganic-based coating more resistant to corrosion producing agents reaching the magnesium containing surface. Vanadium may further infiltrate the inorganic-based coating such that vanadium is distributed throughout at least a portion of the inorganic-based coating. Analysis of inorganic-based coatings according to the invention that have been contacted with a vanadium containing composition showed the presence of vanadium in the inorganic-based coating matrix.
  • Depth of penetration of vanadium second components into the inorganic-based coating matrix may include up to 100, 90, 80, 70, 65, 60, 55 or 50% of total thickness of the porous second sub-layer of the inorganic-based coating, said total thickness being measured from the second interface to the external surface of the inorganic-based coating.
  • the vanadium containing composition may be reactive with elements in the inorganic-based coating. Contacting the inorganic-based coating with a vanadium-containing composition provides improved corrosion resistance and does not cover up the pores in external surfaces of the inorganic-based coating. This is beneficial if a subsequent paint step is to be used because the pores provide anchoring sites for adhering paint to the surface.
  • Another post-treatment step which may be employed is depositing an additional layer comprising a polymer, preferably this may be done using a thermosetting resin which may or may not react with the inorganic-based coating.
  • Average thickness of the polymeric second layer as measured from an external surface of the inorganic-based coating to an outer surface of the second layer, may range from, in order of increasing preference, at least about 0.1, 0.25, 0.5, 0.75, 1, 2, 3, 4, or 5 microns and in order of increasing preference, not more than about 14, 12, 10, 8 or 6 microns.
  • typical paint thicknesses are at least 25 microns thick.
  • Use of either a thin polymeric layer, as described above, or a paint generally covers the pores in the external surfaces of the inorganic-based coating, the pores providing improved adhesion of the polymer or paint and surprisingly resulting in a uniform surface.
  • polymers forming the second layer may comprise organic polymer chains or inorganic polymer chains.
  • polymers suitable for an additional layer include by way of non-limiting example, silicone, epoxy, phenolic, acrylic, polyurethane, polyester, and polyimide.
  • organic polymers selected from epoxy, phenolic and polyimide are utilized.
  • Preferred polymers forming additional layers include phenol-formaldehyde-based polymers and copolymers generated from, for example novolac resins, which have a formaldehyde to phenol molar ratio of less than one, and resole resins having a formaldehyde to phenol molar ratio of greater than one.
  • Such polyphenol polymers can be made as is known in the art for example according to U.S. Pat. No. 5,891,952.
  • Novolac resins are desirably used in combination with a crosslinking agent to facilitate curing.
  • a resole resin having a formaldehyde to phenol molar ratio of about 1.5 is utilized to form a polymer additional layer on the inorganic-based coating.
  • Phenolic resins useful in forming polymeric layers desirably have molecular weights of about 1000 to about 5000 g/mole, preferably 2000 to 4000 g/mole.
  • At least one of the above-described resins is desirably introduced to the first layer of inorganic-based coating, contacting at least the external surfaces thereof, and crosslinking to thereby form a polymeric layer on external surfaces of the inorganic-based coating.
  • This polymeric second layer is different from the inorganic-based coating and is adhered to the inorganic-based coating.
  • the resin may also contact internal surfaces of the inorganic-based coating and upon curing form a polymeric second component that is different from the inorganic-based coating and distributed throughout at least a portion of the inorganic-based coating.
  • Analysis of inorganic-based coatings according to the invention that have been contacted with a resole resin having a formaldehyde to phenol molar ratio of 1.5 showed the polymeric components present in the inorganic-based coating matrix thereby forming a composite coating.
  • Depth of penetration of polymeric second components into the inorganic-based coating matrix may range in increasing order of preference from 1, 2, 5, 10, 15, 20 or 25% and in increasing order of preference may be not more than 70, 65, 60, 55 or 50, 45, 40 or 35% of total thickness of the inorganic-based coating, said total thickness being measured from the first interface to the external surface of the inorganic-based coating.
  • the resin may comprise functional groups reactive with elements in the inorganic-based coating, which may form bonds between the resin and the inorganic-based coating.
  • uncured novolac and resole resins comprise OH functional groups which may react with metals in the inorganic-based coating thereby linking the polymer to the inorganic-based coating.
  • Coated substrates according to the invention are useful in motor vehicles; aircraft and electronics where the combination of the inorganic-based coating and post-treatment layers can provide more corrosion protection than paint or anodizing alone, while ceramic-type hardness of the combination imparts additional toughness to external layers because sharp objects have greater difficulty in deforming a harder substrate prime layer than magnesium, which is relatively soft as compared to ceramic. Coatings according to the invention also can be beneficial in keeping the topcoat gloss and color readings relatively consistent by providing a relatively uniform paint base.
  • the process and coated articles of the invention provide a more uniform surface layer on magnesium alloys, by way of non-limiting example AZ91 B, AZ91 D and AZ31 B, and magnesium containing surfaces having contamination, which provides improved corrosion resistance.
  • the AZ-31 Mg alloy panels were about 93-97 wt. % Mg, the remainder being made up of Al, Zn, Mn, and less than 0.5 wt. % of other metal and metalloid impurities.
  • the AZ-91 Mg alloy panels had less magnesium, about 87-91 wt. % Mg, with the remainder being made up of Al, Zn, Mn, and less than 1.2 wt. % of other metal and metalloid impurities.
  • the conditions for electrolytic coating process for the Examples were an electrolyte bath concentration of 40 grams/liter KF and 5 grams/liter of KOH, temperature was maintained between 20-22 ° C. and the panels and parts were processed for 3 minutes at a current set to reach 160 V (Vmax) within 90 seconds.
  • Vmax refers to the time required for the power source for the electrolytic coating process to reach a maximum voltage set for a process run. After coating and removal from the electrolyte, the coated panels and parts were rinsed with deionized water.
  • All AZ-31 panels were cleaned in 5% BONDERITE® C-AK 305, an alkaline cleaner commercially available from Henkel Corp., at 60 ° C. for 3 minutes; rinsed with DI water; deoxidized in 3% BONDERITE®C-IC HX-357 at 20-22 ° C. for 90 seconds, which was about a 30 g/m 2 etch rate.
  • All AZ-91 panels were cleaned with Turco® 6849 alkaline cleaner for one minute; rinsed with DI water; deoxidized with a commercially available phosphate based deoxidizer at 20-22 ° C. for 60 seconds; desmutted in with a 25,000 KHz ultrasound bath of 1 gram per liter citric acid.
  • AZ-31 Mg alloy panels were immersed in an electrolyte bath containing 40 grams/liter KF and 5 grams/liter of KOH.
  • the panels were electrolyzed as the anode using a 25 msec. on and 9 msec off square waveform for about 180 seconds generating an edge-covering, inorganic-based coating.
  • the coated panels were removed from the electrolyte bath and rinsed with DI water for 300 sec. The coating was observed to have a uniform surface appearance and a thickness of 4 microns.
  • the electrolytically deposited inorganic-based coating was not dried. Thereafter, each coated panel was immersed in an aqueous post-treatment containing one of the compositions recited in Table 1. The coated panels were subjected to 3 minutes of immersion time in the post-treatment tank.
  • the coated and post-treated panels were rinsed with DI water and were allowed to dry. The panels were then subjected to salt fog testing according to ASTM B-117 (2011) and the results after 24 and 168 hours exposure are shown in Table 1.
  • Example 2 A new set of samples treated according to the procedure of Example 1 were prepared using test panels of a different Mg alloy (AZ-91) having higher levels of impurities. Some samples were post-treated with a second commercially available post-treatment instead of the SAVAN. All panels were tested according to the procedure of Example 1 and the test results are shown in Table 2.
  • AZ-31 Mg alloy panels were treated as described in the below Table. All panels had a bare 6061 aluminum skin bonded to the test panel with Terocal 5089 adhesive, commercially available from Henkel Corp. The dissimilar metals were used to set up galvanic reactions in the samples. The panels were scribed through the paint and underlying coatings down to the metal surface and then subjected to 504 hours of salt fog testing according to ASTM B-117. The results are shown in Table 3.
  • Electroceramic coating was an electrolytically applied inorganic-based coating according to the invention having amorphous two layered structure. Paints were commercially available powder paint: Clear Topcoat acrylic (Akzo) cured at 350° F. for 25 minutes; JAVA Brown Fluoropolymer Interpon D3000, cured for 15 minutes at 400° F.; Urethane PCU 73101 silver (PPG) cured at 375° F. for 25 min.; and Polyurethane Silver (Cardinal) cured at 375° F. for 20 minutes.
  • Paints were commercially available powder paint: Clear Topcoat acrylic (Akzo) cured at 350° F. for 25 minutes; JAVA Brown Fluoropolymer Interpon D3000, cured for 15 minutes at 400° F.; Urethane PCU 73101 silver (PPG) cured at 375° F. for 25 min.; and Polyurethane Silver (Cardinal) cured at 375° F. for 20 minutes.
  • Magnesium automobile wheel rims were coated as described in Table 4. The rims were scribed as described for Example 1, and then subjected to 1008 hours of salt fog testing according to ASTM B-117 or to 300 hours GM4472 CASS corrosion testing.
  • the CASS test (Copper Accelerated Salt Spray) is a variant on the salt spray test, with the difference being that the solution used is a mixture of sodium chloride, acetic acid and copper chloride (cupro-acetic mixture), the specifics of the test are available online at GM Matspec. The results are shown in Table 4.
  • Conversion Coating 2 was a commercially available chromium free conversion coating formulated for treating Mg having a typical layer thickness of less than 1 ⁇ m. Electroceramic coating was an inorganic-based coating electrolytically applied according to the invention having amorphous regions and a two layered structure. Urethane paint utilized was PCU 73101 silver powder paint (PPG) cured at 375° F. for 25 min.
  • PPG silver powder paint
  • AZ-91 Mg alloy panels were used for this example and were cleaned as described above. Each of the panels was immersed in one of the electrolyte baths shown in the below table. Fluoride concentration measurement was made with a 101 D meter which measures the fluoride attack on a silicon wafer according to the manufacturer's instructions. The panels were electrolyzed as the anode using a 25 msec. on and 9 msec off square waveform for about 180 seconds. An edge-covering, inorganic-based coating having a uniform surface containing pores, resulted on each of the panels. The coated panels were removed from the electrolyte baths, rinsed with DI water for 240 sec. and allowed to dry. The panels were painted with a liquid paint cured according to manufacturer's specification.
  • the Mg alloy panels coated with the inorganic-based coating and cured layer of paint were tested for corrosion resistance according to ASTM B-117 for 504 hours and were tested for cross-hatch adhesion according to ASTM 3359 method B and the results are shown in the Table 5 below.
  • Sample Groups 5.1 to 5.12 having an inorganic-based coating and a layer of paint showed excellent corrosion resistance and paint adhesion across a range of process parameters and coating thicknesses.
  • the above table shows that by controlling the alkalinity, fluoride concentration and temperature of the electrolyte, the ramp time to Vmax can be and coating thickness can be controlled for a given contact time, current and waveform. Using these non-linear relationships Vmax can be reduced thereby increasing throughput of the process without adversely affecting corrosion resistance or paint adhesion.
  • This experiment tested a new set of samples according to the procedure of Example 1 except that the panels were electrolyzed for a time sufficient to generate a uniform, edge-covering, inorganic-based coating, and an organic-based post-treatment was used instead of a post-treatment.
  • the post-treatment used was a resole resin comprising phenol formaldehyde condensate with a degree of polymerization greater than 1.5.
  • the panel was allowed to dry. Thereafter the organic-based post-treatment was applied and dried for 20 minutes at 160 ° C. (320 ° F.).
  • a first set of panels were provided with a post-treatment having a dried thickness of 6 microns, resulting in a total inorganic/organic coating thickness of 12 microns.
  • a second set of panels were provided with a post-treatment having a dried thickness of 10 microns, resulting in a total inorganic/organic coating thickness of 16 microns. All panels were tested for corrosion resistance according to ASTM B-117. After 1000 hours of testing the panels showed no corrosion at the scribe and did not show any field or edge corrosion.
  • a new set of samples were provided with an electrolytic coating according to the procedure of Example 1.
  • the unpainted panels were subjected to tests as set forth in the table below, which also shows test results.
  • Each specimen had a lap joint with 1′′ overlapping epoxy structural adhesive and 1′′ wide shear specimens. Force was applied at a controlled rate to each specimen until the bond at the lapjoint failed and the maximum force was recorded. Reverse Impact Resistance was tested according to ASTM D2794. Vickers hardness measurement was by nanoindentation and appears to be affected by the underlying alloy.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)
  • Laminated Bodies (AREA)
  • Chemical Treatment Of Metals (AREA)
US15/405,774 2014-07-17 2017-01-13 Electroceramic Coating for Magnesium Alloys Abandoned US20170121841A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2014/047026 WO2016010541A1 (fr) 2014-07-17 2014-07-17 Revêtement électrocéramique pour alliages de magnésium

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2014/047026 Continuation WO2016010541A1 (fr) 2014-07-17 2014-07-17 Revêtement électrocéramique pour alliages de magnésium

Publications (1)

Publication Number Publication Date
US20170121841A1 true US20170121841A1 (en) 2017-05-04

Family

ID=55078871

Family Applications (1)

Application Number Title Priority Date Filing Date
US15/405,774 Abandoned US20170121841A1 (en) 2014-07-17 2017-01-13 Electroceramic Coating for Magnesium Alloys

Country Status (9)

Country Link
US (1) US20170121841A1 (fr)
EP (1) EP3169831A4 (fr)
JP (1) JP6513180B2 (fr)
KR (1) KR20170029545A (fr)
CN (1) CN106715762B (fr)
CA (1) CA2955317A1 (fr)
MX (1) MX2017000559A (fr)
TW (1) TW201619449A (fr)
WO (1) WO2016010541A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180334755A1 (en) * 2017-05-22 2018-11-22 Campagnolo S.R.L. Bicycle gear and method for manufacturing such a gear
CN113514390A (zh) * 2021-03-10 2021-10-19 首钢集团有限公司 一种汽车板电泳漆膜附着力测试方法
US11180832B2 (en) 2018-12-17 2021-11-23 Canon Kabushiki Kaisha Magnesium-lithium alloy member, manufacturing method thereof, optical apparatus, imaging apparatus, electronic apparatus and mobile object

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110505766A (zh) * 2018-05-17 2019-11-26 安克创新科技股份有限公司 保护涂层的制备方法、电路板组件以及电子设备
JP7418117B2 (ja) * 2018-12-17 2024-01-19 キヤノン株式会社 マグネシウム－リチウム系合金部材及びその製造方法
US11613624B2 (en) 2019-11-07 2023-03-28 The Boeing Company Ceramic coated iron particles and methods for making ceramic coated particles
CN112247097B (zh) * 2020-10-22 2022-03-18 重庆建谊祥科技有限公司 一种镁合金建筑模板半固态压铸及双氟化联合制造方法
EP4053309A1 (fr) * 2021-03-01 2022-09-07 Canon Kabushiki Kaisha Élément d'alliage, élément de glissement, appareil, et procédé de fabrication d'un élément d'alliage

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4976830A (en) * 1988-03-15 1990-12-11 Electro Chemical Engineering Gmbh Method of preparing the surfaces of magnesium and magnesium alloys
US5470664A (en) * 1991-02-26 1995-11-28 Technology Applications Group Hard anodic coating for magnesium alloys
US6409844B1 (en) * 1998-03-17 2002-06-25 Matsushita Electric Industrial Co., Ltd. Surface-treated article of magnesium or magnesium alloys, method of surface preparation and method of coating
US6495267B1 (en) * 2001-10-04 2002-12-17 Briggs & Stratton Corporation Anodized magnesium or magnesium alloy piston and method for manufacturing the same

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4184926A (en) * 1979-01-17 1980-01-22 Otto Kozak Anti-corrosive coating on magnesium and its alloys
US4744872A (en) * 1986-05-30 1988-05-17 Ube Industries, Ltd. Anodizing solution for anodic oxidation of magnesium or its alloys
JPS63100195A (ja) * 1986-05-30 1988-05-02 Ube Ind Ltd マグネシウムまたはその合金の陽極酸化処理液
DE3808609A1 (de) * 1988-03-15 1989-09-28 Electro Chem Eng Gmbh Verfahren zur erzeugung von korrosions- und verschleissbestaendigen schutzschichten auf magnesium und magnesiumlegierungen
WO1992014868A1 (fr) * 1991-02-26 1992-09-03 Technology Applications Group, Inc. Procede chimique/electrochimique a deux etapes d'application d'un revetement sur du magnesium
US5226976A (en) * 1991-04-15 1993-07-13 Henkel Corporation Metal treatment
US5266412A (en) * 1991-07-15 1993-11-30 Technology Applications Group, Inc. Coated magnesium alloys
JP2000345370A (ja) * 1999-06-07 2000-12-12 Ueda Alumite Kogyo Kk マグネシウム又はマグネシウム合金の表面処理方法
JP2005272853A (ja) * 2004-03-22 2005-10-06 Nsk Ltd 酸化物被膜を有する機械部品及び該機械部品を備える転動装置、並びに該機械部品の表面処理方法
JP2006183065A (ja) * 2004-12-24 2006-07-13 Aisin Keikinzoku Co Ltd 軽金属等の表面処理方法
US20070256591A1 (en) * 2005-12-30 2007-11-08 Simmons Walter J Corrosion inhibiting inorganic coatings for magnesium alloys
CN101721753B (zh) * 2009-12-23 2014-04-09 天津大学 无机有机防腐生物相容性复合涂层的可吸收镁合金支架及其制备方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4976830A (en) * 1988-03-15 1990-12-11 Electro Chemical Engineering Gmbh Method of preparing the surfaces of magnesium and magnesium alloys
US5470664A (en) * 1991-02-26 1995-11-28 Technology Applications Group Hard anodic coating for magnesium alloys
US6409844B1 (en) * 1998-03-17 2002-06-25 Matsushita Electric Industrial Co., Ltd. Surface-treated article of magnesium or magnesium alloys, method of surface preparation and method of coating
US6495267B1 (en) * 2001-10-04 2002-12-17 Briggs & Stratton Corporation Anodized magnesium or magnesium alloy piston and method for manufacturing the same

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Lin et al Journal of The Electrochemical Society, 153 10 B417-B424 2006 (Year: 2006) *
Wang et al J. Coat. Technol. Res., 7 (6) 737–746, 2010 (Year: 2010) *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180334755A1 (en) * 2017-05-22 2018-11-22 Campagnolo S.R.L. Bicycle gear and method for manufacturing such a gear
IT201700055002A1 (it) * 2017-05-22 2018-11-22 Campagnolo Srl Ingranaggio per bicicletta e metodo per la fabbricazione di tale ingranaggio
EP3406767A1 (fr) * 2017-05-22 2018-11-28 Campagnolo S.r.l. Engrenage de bicyclette et procédé de fabrication d'un tel engrenage
US10900139B2 (en) * 2017-05-22 2021-01-26 Campagnolo S.R.L. Bicycle gear and method for manufacturing such a gear
US11180832B2 (en) 2018-12-17 2021-11-23 Canon Kabushiki Kaisha Magnesium-lithium alloy member, manufacturing method thereof, optical apparatus, imaging apparatus, electronic apparatus and mobile object
CN113514390A (zh) * 2021-03-10 2021-10-19 首钢集团有限公司 一种汽车板电泳漆膜附着力测试方法

Also Published As

Publication number Publication date
JP6513180B2 (ja) 2019-05-15
WO2016010541A1 (fr) 2016-01-21
KR20170029545A (ko) 2017-03-15
CN106715762A (zh) 2017-05-24
MX2017000559A (es) 2017-04-27
EP3169831A1 (fr) 2017-05-24
JP2017520684A (ja) 2017-07-27
CN106715762B (zh) 2019-07-12
CA2955317A1 (fr) 2016-01-21
EP3169831A4 (fr) 2018-02-07
TW201619449A (zh) 2016-06-01

Similar Documents

Publication Publication Date Title
US20170121841A1 (en) Electroceramic Coating for Magnesium Alloys
US7922889B2 (en) Anodising aluminum alloy
JP5016493B2 (ja) アルミニウムおよび／またはチタンをセラミック酸化物で陽極被覆する製造品およびプロセス
JP4886697B2 (ja) アルミニウムおよびアルミニウム合金被覆基材上の陽極酸化被膜および被覆物品
KR100768565B1 (ko) 전도성 표면을 처리하는 에너지 개선방법
JP2008518096A (ja) 有機または無機被膜の前に、セラミック酸化物でアルミニウム基材を陽極被覆する、製造物品およびプロセス
Seifzadeh et al. Electroless Ni–P plating on magnesium alloy by innovative, simple and non-toxic oxalate pretreatment and its corrosion protection
WO2015091932A1 (fr) Procédé de formation d'un revêtement anodique multicouche
Luan et al. Corrosion protection of magnesium (Mg) alloys using conversion and electrophoretic coatings
Howlett et al. Conversion coatings of Mg-alloy AZ91D using trihexyl (tetradecyl) phosphonium bis (trifluoromethanesulfonyl) amide ionic liquid
Fazal et al. Formation of cerium conversion coatings on AZ31 magnesium alloy
US20190316270A1 (en) Dark colored electroceramic coatings for magnesium
Bestetti et al. Anodic oxidation and powder coating for corrosion protection of AM6oB magnesium alloys
JP3105322B2 (ja) 光輝性アルミホイールの無色クロメート皮膜形成方法
US20240133073A1 (en) A process to protect light metal substrates
Hesamedini Trivalent chromium based conversion coatings containing cobalt on the zinc plated steel
Zhao et al. Improvement of bonding strength of AZ31B magnesium alloy by anodizing and chromium-free conversion treatments
Lampman Chemical Conversion Coatings
JP3224639B2 (ja) アルミホイールの無色クロメート皮膜形成方法
KR20180088966A (ko) 마그네슘의 표면 처리 방법
JP2009299082A (ja) 金属の処理方法、金属基材の製造方法、及び金属基材

Legal Events

Date Code Title Description
AS Assignment

Owner name: HENKEL AG & CO. KGAA, GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:DOLAN, SHAWN E.;KRAMER, KIRK;SALET, LISA K.;AND OTHERS;SIGNING DATES FROM 20170516 TO 20170517;REEL/FRAME:042419/0936

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: FINAL REJECTION MAILED

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION