Multi-stage aluminum alloy forming and thermal processing method for the production of vehicle components

Abstract

A method of forming and processing a high strength aluminum alloy for the production of a vehicle component includes providing a metal sheet that was rolled from an aluminum alloy. The sheet is heat treated through a first aging step of a set of aging steps that are necessary to achieve a T6 or a T7 temper state. Prior to achieving the T6 or a T7 temper state, the sheet is formed to a desired shape and welded in the desired shape to produce a desired vehicle component. Once formed, the vehicle component is heat treated through a remaining aging step to achieve a T6 or T7 temper state homogeneously throughout the vehicle component.

What is claimed is: 
     
         1 . A method comprising:
 providing an aluminum alloy sheet that has been heat treated through a first aging step of a plurality of aging steps necessary to achieve a final temper state, the first aging step bringing the aluminum alloy sheet to an intermediate temper state;   forming the aluminum alloy sheet in a forming station to form the aluminum alloy sheet to a desired shape;   welding the aluminum alloy sheet in the desired shape with a fusion welding process in a welding station following the forming station without any processing steps between the forming station and the welding station to provide a component; and   heat treating the component through a final aging step of the plurality of aging steps to achieve the final temper state, wherein the final aging step comprises heating the component in a paint bake operation.   
     
     
         2 . The method of  claim 1 , further comprising:
 heat treating the component through a second aging step of the plurality of aging steps to achieve a second intermediate temper state, wherein the second aging step is performed after the first aging step and before the final aging step.   
     
     
         3 . The method of  claim 1 , wherein the first aging step comprises heat treating the aluminum alloy sheet for approximately 5 to 6 hours at around 100 degrees Celsius. 
     
     
         4 . The method of  claim 1 , wherein the final aging step comprises heat treating the component for approximately 10 to 18 hours above 130 degrees Celsius. 
     
     
         5 . The method of  claim 1 , wherein heat treating the processed component through the final aging step provides the final temper state homogeneously throughout the component. 
     
     
         6 . The method of  claim 1 , wherein the forming station comprises a set of rollers that roll form the aluminum alloy sheet by successively imparting deformation in the aluminum alloy sheet to form a beam. 
     
     
         7 . The method of  claim 1 , wherein an edge portion of the aluminum alloy sheet is welded to another portion of the aluminum alloy sheet to fix the aluminum alloy sheet in a tubular shape. 
     
     
         8 . The method of  claim 1 , wherein the desired shape includes a beam having two enclosed tubular shapes. 
     
     
         9 . The method of  claim 1 , wherein the aluminum alloy sheet is fed into the forming station and sequentially into the welding station to be welded in a consistent cross-sectional shape along a length of the component. 
     
     
         10 . The method of  claim 1 , wherein the final temper state comprises a T6 temper state or a T7 temper state. 
     
     
         11 . The method of  claim 1 , wherein the aluminum alloy sheet comprises a 7xxx series aluminum alloy. 
     
     
         12 . The method of  claim 1 , wherein the component comprises a reinforcement beam for a vehicle. 
     
     
         13 . A method comprising:
 providing an aluminum alloy sheet in a W temper state;   heat treating the sheet through a first aging step of a plurality of aging steps that are necessary for the sheet to achieve a final temper state of T6 or T7;   forming the sheet in a forming station to a desired shape;   welding the sheet with a welder in a welding station sequentially after the forming station without any processing steps between the forming station and the welding station to provide a vehicle component; and   heat treating the vehicle component through a final aging step of the plurality of aging steps to achieve the final temper state, wherein the final aging step comprises heat treating the welded sheet in a paint bake operation.   
     
     
         14 . The method of  claim 13 , wherein by roll forming and welding before the final aging step, the vehicle component is less susceptible to stress corrosion cracking than such a component formed and subsequently fusion welded from a sheet in a T6 or T7 temper state. 
     
     
         15 . The method of  claim 13 , wherein the sheet comprises a 7xxx series aluminum alloy. 
     
     
         16 . The method of  claim 13 , wherein the first aging step includes heat treating the sheet at around 100 degrees Celsius for a period of time that does not allow the sheet to achieve a T6 or a T7 temper state. 
     
     
         17 . The method of  claim 13 , wherein the remaining aging step includes heat treating the vehicle component for at around 150 degrees Celsius until the vehicle component reaches a T6 or a T7 temper state. 
     
     
         18 . The method of  claim 13 , wherein welding the sheet includes welding an edge portion of the sheet to another portion of the aluminum alloy sheet along a length of the sheet product to enclose the at least one tubular shape in forming the vehicle component. 
     
     
         19 . The method of  claim 18 , wherein forming the sheet includes roll forming the sheet to form a reinforcement beam having at least one enclosed area. 
     
     
         20 . The method of  claim 18 , wherein welding the sheet causes an area at a welded portion of the sheet to achieve a W temper state, and wherein the area at the welded portion achieves a T6 or a T7 temper state upon heat treating the vehicle component through the remaining aging step.