Aluminum alloy and extrusion

摘要

A population of extrusion billets has a specification such that every billet is of an alloy of composition (in wt. %): Fe<0.35; Si 0.20-0.6; Mn<0.10; Mg 0.25-0.9; Cu<0.015; Ti<0.10; Cr<0.10; Zn<0.03; balance Al of commercial purity. After ageing to T5 or T6 temper, extruded sections can be etched and anodised to give extruded matt anodised sections having improved properties.