Patent ID: 6267830
Filing Date: 2001-07-31
Classification: A47J,B21B,B23K,B32B,Y10T

Abstract:
A method of making a 5-ply composite metal product comprising the steps of:providing a prebonded composite consisting of a copper core having pure aluminum cold roll bonded on opposed sides of the copper core, said prebonded composite being free from one or more aluminum alloy layers; andbonding a sheet of stainless steel to the pure aluminum on opposed sides of said prebonded composite to provide the 5-ply composite metal product, consisting essentially of layers of stainless steel, pure aluminum, copper, pure aluminum and stainless steel, wherein the copper layer has a thickness greater than any of the other layers, and wherein the aluminum layers each have a thickness less than any of the other layers,wherein the prebonded composite is formed by cold rolling a high purity copper sheet and pure aluminum sheets at a reduction of about 50% followed by a post cold roll heating at a maximum temperature of 550.degree. F., and wherein said bonding of the stainless steel to the prebonded composite is carried out by hot rolling comprising the steps of heating the stainless steel and the prebonded composite to a temperature of between 520.degree.-600.degree. F. and rolling the metals in a stacked array in a first rolling pass at a reduction of 2% to 10% and in a second rolling pass at a reduction of 10% to 30%, followed by a post hot roll heating not to exceed 600.degree. F. to achieve temperature homogeneity within the rolled metals, followed by immediate cooling to avoid formation of brittle intermetallic compounds between the copper and aluminum.