METHOD FOR THE MANUFACTURING OF EXTRUDED PROFILES THAT CAN BE ANODIZED WITH HIGH GLOSS SURFACES, THE PROFILES BEING EXTRUDED OF AN AGE HARDENABLE ALUMINIUM ALLOY THAT CAN BE RECRYSTALLIZED AFTER COLD DEFORMATION, FOR EXAMPLE A 6XXX OR A 7XXX ALLOY

摘要

Method for the manufacturing of extruded profiles that can be anodized with high gloss surfaces, the profiles being extruded of an age hardenable aluminium alloy that can be recrystallized after cold deformation, for example a 6xxx or 7xxx alloy, where the alloy initially is cast to extrusion billet(s), where the billets are homogenized at a holding temperature between 480° C. and 620° C. and soaked at this temperature for 0-12 hours, where after the billets are subjected to cooling from the homogenization temperature at a rate of 150° C./h or faster, a) the billets are preheated to a temperature between 400 and 540° C. and extruded preferably to a solid shape profile and cooled rapidly down to room temperature, b) deforming the profile more than 10% by a cold rolling operation, where after c) the profile is flash annealed with a heating time of maximum two minutes to a temperature of between 400-530° C. and held at this temperature for not more than 5 minutes to obtain an average grain size of about 100 μm or less, and subsequently quenched, d) and the profile is finally aged.