Patent ID: 9255315
Filing Date: 2016-02-09
CPC Classification: B22D,C22C,C22F,F41H

Claim Text:
1. A method of manufacturing an aluminium alloy plate having improved resistance against incoming kinetic energy projectiles, the plate having a final gauge of 10 mm or more, the method comprising the following steps: (a) casting an aluminum alloy having a chemical composition comprising, in weight percent: Mg 4.0 to 6.0 Mn 0.2 to 1.4 Zn 0.9 max. Zr<0.3 Cr<0.3 Sc≦0.5 Ti≦0.3 Fe<0.5 Si<0.45 Ag<0.4 Cu<0.25, other elements and unavoidable impurities each <0.05, total <0.20, balance aluminum, (b) preheating and/or homogenisation, (c) hot rolling, (d) a first cold working operation selected from the group consisting of stretching in the range of 2 to 15% and cold rolling with a cold rolling reduction of 4 to 12%, (e) an annealing treatment at a temperature of less than 350° C., followed by (f) a second cold working operation consisting of stretching in a range of 2 to 15%, and wherein the manufacturing process of the alloy plate at final gauge after the cold working operation is devoid of a further heat treatment, such that no substantial recovery occurs in the alloy plate.