Title: Method of making hollow bodies
Application Number: 94191766 Application Date: 1994.04.15
Publication Number: 1120855 Publication Date: 1996.04.17
Approval Pub. Date: 2001.01.24 Granted Pub. Date: 2001.01.24
International Classifi-cation: C22C21/10;C22F1/053
Applicant(s) Name: Alcan International Limited Address:
Inventor(s) Name: Nigel John Henry Holroyd;Warren Hepples
Attorney & Agent: LU XINHUA LUO CAIXI
Abstract:
    A method of making a pressurised gas cylinder comprises providing an ingot of composition (in wt. %): Zn 5.0 - 7.0; Mg 1.5 - 3.0; Cu 1.0 - 2.7; recrystallisation inhibitor 0.05 - 0.40; Fe up to 0.30; Si up to 0.15; other impurities up to 0.05 each and 0.15 in total, balance Al of at least commercial purity, if necessary homogenising the ingot at a temperature of at least 470 DEG C and for a time sufficient to reduce the volume fraction of S phase to a value below 1.0 %, extruding the ingot preferably by cold backward extrusion, and forming and over-ageing the resulting pressurised gas cylinder.
Time: 8