Al-Mg-Si alloy with good extrusion properties
AssigneeAlcan International Limited
InventorsNicholas Charles Parson, Jeffrey David Hankin, Kevin Paul Hicklin
Life of this patent
Estimating the term…
Abstract
An alloy of composition in wt. % (see table (I)) and incidental impurities up to 0.05 each 0.15 total, balance A1. The alloy can be extruded at high speed to provide extruded sections which meet T5 or T6 strength requirements.
Claims19
A DC cast extrusion ingot of an alloy of composition consisting of 0.20-0.34 wt. % Mg, 0.35-0.60 wt. % Si, 0.02-0.15 wt. % Mn, up to 0.10 wt. % Cu, up to 0.35 wt. % Fe, optionally Ti and B as grain refiners, incidental impurities up to 0.05 wt. % each, up to 0.15 wt. % total, balance Al, provided that when Mg is at least 0.30 wt % and Cu is at least 0.05 wt %, then Fe is greater than 0.15 wt %.
A method of making an extrusion, comprising DC casting an extrusion ingot of an alloy of composition consisting of 0.20-0.34 wt. % Mg, 0.35-0.60 wt % Si, 0.02-0.15 wt. % Mn, up to 0.10 wt. % Cu, up to 0.35 wt. % Fe, optionally Ti and B as grain refiners, incidental impurities up to 0.05 wt. % each, up to 0.15 wt. % total, balance Al, provided that when Mg is at least 0.30 wt % and Cu is at least 0.05 wt %, then Fe is greater than 0.15 wt %;
- homogenising the ingot to convert β-AlFeSi particles to substantially an α-Al-Fe-Si form;
- cooling the homogenised ingot;
- and extruding the ingot.
A DC cast extrusion ingot of an alloy of composition consisting of 0.20-0.34 wt. % Mg, 0.40-0.59 wt. % Si, 0.03-0.10 wt. % Mn, up to 0.10 wt. % Cu, up to 0.35 wt. % Fe, optionally Ti and B as grain refiners, incidental impurities up to 0.05 wt. % each, up to 0.15 wt. % total, balance Al, provided that when Mg is at least 0.30 wt % and Cu is at least 0.05 wt %, then Fe is greater than 0.15 wt %;
- in which AlFeSi phase is present and more than 80% of said AlFeSi is present as α-AlFeSi, by virtue of homogenisation.
Dependencies are inferred from the claim text.