The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 25, 1999
Filed:
Sep. 30, 1997
Ulrich Heinzel, Bremen, DE;
Daimler-Benz Aerospace Airbus GmbH, Hamburg, DE;
Abstract
A method for testing and determining the alloy class of an aluminum alloy may be simply and easily carried out, for unequivocally determining the correct alloy class among the aluminum alloy classes 2XXX, 5XXX or 6XXX, and 7XXX, of the test sample. According to the method, the material sample is dissolved in hydrochloric acid (HCL) to prepare a first solution, then nitric acid (HNO.sub.3) is added drop-wise to the first solution in order to cause oxidation of any insoluble copper (Cu) therein and form a second solution, then a potassiumhexacyanoferrate (II) solution (K.sub.4 �Fe(CN).sub.6 !) is added to the second solution to bring about a discoloration and precipitation reaction and form a final resulting solution. Finally, the applicable alloy class of the tested material sample is determined by visually categorizing the color and precipitation state of the resulting solution. A brown cloudy solution indicates a 2XXX alloy, a gray-green cloudy solution indicates a 7XXX alloy, and a blue or green transparent solution indicates a 5XXX or 6XXX alloy.