Alcan International Limited

Michael John Wheeler

Michael Jackson Bull

Alok Kumar Gupta

Pierre Henri Marois

Greg J Courval

Ian Wilson

David F Charles

Michael P Thomas

Application of surface marking to metal stock, such as aluminum sheet, prior to or during scrap-generating manufacturing operations, to provide a detectable mark on pieces of manufacturing scrap derived from the marked sheet and commingled with scrap of other aluminum alloy sheet, so that the scrap can be sorted and the marked alloy scrap pieces separated from scrap of other alloy sheet to which the marking was not applied. Different markings, providing detectably different marks, may be respectively applied to sheet of different compositions if scrap pieces of more than two different compositions or compositional families are to be sorted and separated from each other.

Method of applying marking to metal sheet for scrap sorting purposes

An aluminum alloy containing the following elements in the stated amounts: 0.6&lE;Mg&lE;0.9; 0.25&lE;Si&lE;0.6; 0.25&lE;Cu&lE;0.9; Fe<0.4; Mn<0.4; the total of the amounts of Cu, Si and Mg being, in atomic weight percent, more than 1.2% and less than 1.8%. These alloys may be subjected to homogenization at about 470 to 560&deg; C. for more than four hours, hot rolling at a temperature in the range of 400 to 580&deg; C., cold rolling, solutionizing at a temperature in the range of 470 to 580&deg; C., and natural aging at ambient temperature. The alloys may then be used as structural components for all aluminum vehicles and may be recycled with other aluminum alloys used in such vehicles.

Precipitation-hardened aluminum alloys for automotive structural applications

A process of producing solution heat treated aluminum alloy sheet material comprises subjecting hot- or cold-rolled aluminum alloy sheet to solution heat treatment followed by quenching and, before substantial age hardening has taken place, subjecting the alloy sheet material to one or more subsequent heat treatments involving heating the material to a peak temperature in the range of 100.degree. to 300.degree. C. (preferably 130.degree.-270.degree. C.), holding the material at the peak temperature for a period of time less than about 1 minute, and cooling the alloy from the peak temperature to a temperature of 85.degree. C. or less. The sheet material treated in this way can by used for automotive panels and has good a good 'paint bake response', i.e. an increase in yield strength from the T4 temper to the T8X temper upon painting and baking of the panels.

Heat treatment process for aluminum alloy sheet

Growing community of inventors

Kingston, Canada

Michael John Wheeler