Abstract

The invention relates to an aqueous composition for the electrolytic deposition of a chromium coating on the surface of a substrate, which has a pH of between 0 and 1 and which contains a trivalent chromium salt, glycine, an alkali metal salt, an aluminium salt and, optionally, an ammonium salt. The chromium plating process according to the invention comprises the immersion of the substrate to be treated in this composition and the application of a current between this substrate and an anode. This process makes it possible to form a high-quality chromium coating on the entire surface of the substrate.

IPC Classes  ?

• C25D 3/06 - Electroplating; Baths therefor from solutions of chromium from solutions of trivalent chromium
• C25D 3/12 - Electroplating; Baths therefor from solutions of nickel or cobalt

Abstract

2.

IPC Classes  ?

• C25D 11/08 - Anodisation of aluminium or alloys based thereon characterised by the electrolytes used containing inorganic acids
• C25D 11/02 - Anodisation
• C25D 11/16 - Pretreatment
• C25D 11/24 - Chemical after-treatment
• C25D 11/38 - Chromatising

Abstract

A method for surface treatment of a part made of aluminum, magnesium, or one of the alloys thereof, to protect the part from corrosion. The method comprises consecutively immersing the part in a first aqueous bath containing a corrosion-inhibiting metal salt and an oxidizing compound, and a second aqueous bath containing an oxidizing compound and a corrosion-inhibiting rare-earth salt. The method can be carried out for the chemical conversion of aluminum or the alloys thereof, and of magnesium or the alloys thereof, on parts that have not been previously treated, or after anodizing the part to seal the anodic layer.

IPC Classes  ?

• C23C 22/83 - Chemical after-treatment
• C23C 22/56 - Treatment of aluminium or alloys based thereon
• C23C 22/34 - Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH < 6 containing fluorides or complex fluorides
• C25D 11/18 - After-treatment, e.g. pore-sealing
• C25D 11/04 - Anodisation of aluminium or alloys based thereon
• C25D 11/30 - Anodisation of magnesium or alloys based thereon
• C23C 22/57 - Treatment of magnesium or alloys based thereon
• C23G 1/00 - Cleaning or pickling metallic material with solutions or molten salts
• C23C 22/00 - Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
• C25D 11/24 - Chemical after-treatment

Abstract

The invention relates to a method for the surface treatment of a part made of aluminum, magnesium, or one of the alloys thereof, with a view to protecting said part from corrosion, said method including consecutively immersing the part in a fist aqueous bath containing a corrosion-inhibiting metal salt and an oxidizing compound, and a second aqueous bath containing an oxidizing compound and a corrosion-inhibiting rare-earth salt. Said method can be carried out for the chemical conversion of aluminum or the alloys thereof, and of magnesium or the alloys thereof, on parts that have not been previously treated, or after a step of anodizing the part, in order to seal the anodic layer.

IPC Classes  ?

• C23C 22/34 - Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH < 6 containing fluorides or complex fluorides
• C23C 22/83 - Chemical after-treatment
• C25D 11/24 - Chemical after-treatment

Abstract

The invention relates to a method for anodizing a part made of aluminum or of an aluminum alloy, by immersing the part in an aqueous bath essentially comprising sulfuric acid at a concentration of 150 to 250 g/L and at a temperature of 5 to 25°C, then applying, to the part, a DC voltage according to a voltage profile comprising a voltage increase at a rate of 1 to 32 V/min, and then maintaining the voltage at a so-called plateau voltage value of 12 to 20 V for a duration sufficient for obtaining, at the surface of the part, an anode layer having a thickness of 3 to 7 µm and/or a layer weight of 20 to 150 mg/dm2.

IPC Classes  ?

• C25D 11/08 - Anodisation of aluminium or alloys based thereon characterised by the electrolytes used containing inorganic acids
• C25D 11/02 - Anodisation
• C25D 11/16 - Pretreatment
• C25D 11/24 - Chemical after-treatment
• C25D 11/38 - Chromatising

Abstract

The invention relates to a method for anodizing a part made of aluminum or of an aluminum alloy, by immersing the part in an aqueous bath essentially comprising sulfuric acid at a concentration of 150 to 250 g/L and at a temperature of 5 to 25°C, then applying, to the part, a DC voltage according to a voltage profile comprising a voltage increase at a rate of 1 to 32 V/min, and then maintaining the voltage at a so-called plateau voltage value of 12 to 20 V for a duration sufficient for obtaining, at the surface of the part, an anode layer having a thickness of 3 to 7 μm and/or a layer weight of 20 to 150 mg/dm2.

IPC Classes  ?

• C25D 11/08 - Anodisation of aluminium or alloys based thereon characterised by the electrolytes used containing inorganic acids
• C25D 11/16 - Pretreatment
• C25D 11/24 - Chemical after-treatment
• C25D 11/38 - Chromatising
• C25D 11/02 - Anodisation

Abstract

The invention relates to a method for the surface treatment of a part made of aluminum, magnesium, or one of the alloys thereof, with a view to protecting said part from corrosion, said method including consecutively immersing the part in a fist aqueous bath containing a corrosion-inhibiting metal salt and an oxidizing compound, and a second aqueous bath containing an oxidizing compound and a corrosion-inhibiting rare-earth salt. Said method can be carried out for the chemical conversion of aluminum or the alloys thereof, and of magnesium or the alloys thereof, on parts that have not been previously treated, or after a step of anodizing the part, in order to seal the anodic layer.

IPC Classes  ?

• C23C 22/34 - Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH < 6 containing fluorides or complex fluorides
• C23C 22/83 - Chemical after-treatment
• C25D 11/24 - Chemical after-treatment

Abstract

The invention relates to an anticorrosion treatment process in which applied to an oxidizable surface of a solid metal substrate is a liquid solution, referred to as treatment solution, comprising: at least one alkoxysilane, and at least one cerium (Ce) cation; in a liquid aqueous-alcoholic composition, said treatment solution being suitable for being able to form, at the surface of the solid metal substrate, a hybrid matrix by hydrolysis/condensation of each alkoxysilane(s) and of each cerium (Ce) cation; the treatment solution having a molar ratio (Si/Ce) of silicon element of the alkoxysilane(s) with respect to the cerium (Ce) cation(s) of between 50 and 500; characterized in that the cerium (Ce) cation(s) has(have) a concentration between 0.005 mol/L and 0.015 mol/L in the treatment solution.

IPC Classes  ?

• C23C 22/56 - Treatment of aluminium or alloys based thereon
• C23C 22/83 - Chemical after-treatment
• C23C 18/12 - Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of inorganic material other than metallic material

Abstract

The invention relates to an anticorrosion treatment process in which applied to an oxidizable surface of a solid metal substrate is a liquid solution, referred to as treatment solution, comprising at least one alkoxysilane in a liquid aqueous-alcoholic composition, said treatment composition being suitable for being able to form, at the surface of the solid metal substrate, a hybrid matrix by hydrolysis/condensation of the alkoxysilane(s) characterized in that, before applying the treatment solution, said oxidizable surface of the metal substrate is brought into contact with an aqueous liquid solution, referred to as conversion solution, of at least one corrosion inhibitor, said at least one corrosion inhibitor being chosen from the group formed of cations of lanthanides and said oxidizable surface of the metal substrate is kept in contact with the conversion solution under conditions suitable for forming a conversion layer of at least one lanthanide bonded via at least one covalent bond to the oxidizable surface and spreading out at the surface of the metal substrate.

IPC Classes  ?

• C23C 22/56 - Treatment of aluminium or alloys based thereon
• C23C 22/83 - Chemical after-treatment
• C25D 9/06 - Electrolytic coating other than with metals with inorganic materials by anodic processes
• C23C 18/12 - Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of inorganic material other than metallic material

Abstract

The invention relates to a method of regenerating a spent titanium etching solution that is based on hydrofluoric acid and nitric acid and contains dissolved titanium. Said method involves determining the hydrofluoric acid and nitric acid concentrations in the solution, comparing each of the measured values with a respective associated predetermined threshold value, and adding KF and/or KNO3 to the solution when the respective HF and/or HNO3 concentration in the solution is below the associated threshold value. The method also includes determining the titanium concentration in the solution, comparing the measured value with a predetermined limit, and adding KF and KNO3 to the solution if the measured value exceeds said limit.

IPC Classes  ?

• C23F 1/46 - Regeneration of etching compositions
• C23G 1/36 - Regeneration of waste pickling liquors
• C01G 23/00 - Compounds of titanium