US Patent 7820304 Corrosion/abrasion-resistant composite cookware

A composite metal sheet (20) comprising a core layer (24) of drawable aluminum alloy such as 3003 or 3004 aluminum alloy roll bonded to a thinner layer (26) of 5456 aluminum alloy, the composite metal sheet including a layer (22) of stainless steel roll bonded to the layer of drawable aluminum (24) on the opposite side from the 5456 aluminum alloy layer (26). The composite metal sheet is useful in forming drawn cookware (2) such as fry pans, stock pots, and the like wherein the stainless steel layer (22) forms the cooking surface and the 5456 aluminum alloy layer (26) forms the exterior surface of the cookware.