Swiss Aluminium Ltd.

Swiss Aluminum Ltd.

Gunter Hollrigl

Ladislav Sandera

Pedro Rodrigues

In a process for manufacturing a fine-grained recrystallized sheet of heat-treatable i.e. age-hardenable aluminum alloy containing an addition of at least one of the elements Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W amounting in total to 0.08-1.50%, the alloy is brought into a condition A in which the alloying elements that lead to age-hardening and the above mentioned additive elements are, at least for the greater part, in solid solution, following which in step B the incoherent hardening phases are precipitated out in a temperature range between the solvus T.sub.gps and the solvus T.sub.s, and in a subsequent step C the aluminides of the above mentioned elements are precipitated as a very dense uniform dispersion by heating in a temperature range between 300.degree. C. and T.sub.s -30.degree. C., whereby any deformation by rolling may take place between condition A and step C at temperatures not higher than T.sub.s -30.degree. C., and in which process the temperature of the sheet below a thickness or 2.5 xd does not exceed 200.degree. C., and the sheet at thickness d is heated to a recrystallization treatment D such that the heating rate is at least 20.degree. C./s until above the recrystallization threshold.

Process for manufacturing a fine-grained recrystallized sheet

Continuous process for anodizing and subsequent electrolytic coloring of an aluminium strip or foil with A.C. in which the strip after leaving the anodistaion unit passes through an aqueous acidic contacting electrolyte, e.g. dilute sulfuric acid, and then through the aqueous acidic coloring electrolyte containing metal ions and in which the A.C. source is connected to inert electrodes dipping in the contacting and in the coloring electrolyte respectively.

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Schaffhausen, Switzerland

Gunter Hollrigl