Patent ID: 6077363
Filing Date: 2000-06-20
Classification: B32B,C22F,Y10T

Abstract:
A metal sheet with a total thickness >0.5 mm, comprising an AlCuMg aluminum alloy consisting essentially of Al and, in % by weight: 3.5 < Cu < 5.0 1.0 < Mg < 2.0 Si < 0.25 Fe < 0.25 Mn < 0.55  all other elements: <0.25with 0<Mn-2Fe<0.2,optionally plated with another aluminum alloy with the thickness of the plating being no more than 12% of the total thickness of the sheet, said sheet having a recrystallization rate >50% at all points and a deviation in recrystallization rate between surface and mid-thickness <35%, said sheet having in the quenched and stretched state or the quenched, stretched and annealed state, a deflection after a machining to mid-thickness of a bar resting on two distant supports with a length l such that:fe<0.14l.sup.2,with f being the deflection expressed in micrometers, e being the thickness of the sheet in mm and l being the length of the bar in mm.