A process of preventing crack formation in chemical conversion coating comprising providing a substrate; introducing a chemical conversion coating material; adding an additive containing a binder to the conversion coating material; and coating the substrate with the chemical conversion coating and the additive.

A process of preventing crack formation in chemical conversion coating comprising providing a substrate; introducing a chemical conversion coating material; adding an additive containing a binder to the conversion coating material; and coating the substrate with the chemical conversion coating and the additive.

There is provided a coating for corrosion protection of metal objects, said coating comprising at least one cerium oxide and at least one polypeptide, wherein the polypeptide comprises 29 or less amino acid residues wherein at least 15% of the number of amino acid residues are DOPA. Advantages include a fast establishment of the corrosion protective properties in an applied coating.

Described are techniques for making aluminum alloy products and methods for pre-treating aluminum alloys with small molecules, and the resultant aluminum alloy products, in which small molecules including phosphorus-containing organic acid functionality, such as organo-phos-phonic acids, are applied to a surface of an aluminum alloy product to generate a self-assembled monolayer or multilayer of small molecules on the surface of the aluminum alloy product. Mixtures of different phosphorus-containing organic acids may be employed. At least some of the phospho-ms-containing organic acids may exhibit a hydrophilic character, such as by including one or more hydrophilic functional groups. The self-assembled monolayer or multilayer including hydrophilic functionality may advantageously allow the aluminum alloy product to have a good wettability by water and other hydrophilic substances, such as some epoxy adhesives, but also to have a good wet-tability by hydrophobic substances, such as some lubricants.

Described are techniques for making aluminum alloy products and methods for pre-treating aluminum alloys with small molecules, and the resultant aluminum alloy products, in which small molecules including phosphorus-containing organic acid functionality, such as organo-phos-phonic acids, are applied to a surface of an aluminum alloy product to generate a self-assembled monolayer or multilayer of small molecules on the surface of the aluminum alloy product. Mixtures of different phosphorus-containing organic acids may be employed. At least some of the phospho-ms-containing organic acids may exhibit a hydrophilic character, such as by including one or more hydrophilic functional groups. The self-assembled monolayer or multilayer including hydrophilic functionality may advantageously allow the aluminum alloy product to have a good wettability by water and other hydrophilic substances, such as some epoxy adhesives, but also to have a good wet-tability by hydrophobic substances, such as some lubricants.

The present invention relates to metals or metal alloys comprising a protective silicate glass-like coating, and methods for coating the metals or metal alloys. The methods comprise removal of any existing oxide layer from the metal or metal alloy, formation of a new oxide layer on the metal or metal alloy using chemical passivation or exposure to a gaseous oxidising environment, coating the oxidised metal or metal alloy with an aqueous silicate solution, and curing the coating.

The present invention relates to metals or metal alloys comprising a protective silicate glass-like coating, and methods for coating the metals or metal alloys. The methods comprise removal of any existing oxide layer from the metal or metal alloy, formation of a new oxide layer on the metal or metal alloy using chemical passivation or exposure to a gaseous oxidising environment, coating the oxidised metal or metal alloy with an aqueous silicate solution, and curing the coating.

A method for producing a diaphragm for an ultrasonic sensor. In the method, a diaphragm body made of metal material is first provided. Next, an external surface region of the diaphragm body is degreased. The external surface region of the diaphragm body is then pickled. To pre-activate the subsequently applied second passivation layer, a first passivation layer is also deposited on the external surface region as a first layer.

A method for producing a diaphragm for an ultrasonic sensor. In the method, a diaphragm body made of metal material is first provided. Next, an external surface region of the diaphragm body is degreased. The external surface region of the diaphragm body is then pickled. To pre-activate the subsequently applied second passivation layer, a first passivation layer is also deposited on the external surface region as a first layer.

Disclosed herein is an aqueous composition having a pH value at 55° C. in the range from 5 to 9, containing at least two different amino organophosphonic acid derivatives of formula (I)

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where residues R independently of each other are CH.sub.2—PO(OR″).sub.2, residues R′ independently of each other are alkylene residues with 2 to 4 carbon atoms, residues R″ independently of each other are H, Na, K, Li or NH.sub.4; and n is an integer from 0 to 4; and where the at least two different amino organophosphonic acid derivatives differ in the value of n. Further disclosed herein is a concentrate to produce such compositions, a pickling method for pickling metallic substrates making use of the compositions, a coating method for coating metallic substrates including the pickling method and a method of using the compositions for pickling metallic substrates.