Patent · US Expired

Method of preparing the surfaces of magnesium and magnesium alloys

US4976830A · kind A · utility

19Cited by

1References

16Claims

0Family size

Assignee

Electro Chemical Engineering GmbH · CH

Inventors

Edith L. Schmeling · Brühl, DE
Benno Roschenbleck · Osnabrück, DE
Michael Weidemann · Berlin, DE

Key dates

Filing date	Mar 9, 1989
Grant date	Dec 11, 1990
Priority date	—
Expiry date	Mar 9, 2009

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC25D11/30
WIPO fieldSurface technology, coating
WIPO sectorChemistry

Abstract

A method of preparing the surfaces of magnesium and magnesium alloys by anodic oxidation. To produce protective coatings that have little or no inherent color, that can easily be colored, that provide a satisfactory adhesive base for lacquering or subsequent processing, and that exhibit outstanding resistance to corrosion and wear on magnesium and magnesium alloys by anodic oxidation, an alkali-rich aqueous electrolyte bath containing PA0 (a) borate or sulfonate anions and PA0 (b) phosphate and fluoride or chloride ions and adjusted to a pH of 8 to 12 and preferably 10.5 to 11.5 is employed. A direct current is applied and is either briefly turned off or its polarity incompletely reversed to allow the formation of magnesium phosphate and magnesium fluoride or magnesium chloride and optionally magnesium aluminate.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.