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US 3,945,861 AGranted
High strength automobile bumper alloy
AssigneeAluminum Company of America
InventorsWilliam A. Anderson, Ralph W. Rogers, Jr., William D. Vernam
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AssigneeAluminum Company of America
InventorsWilliam A. Anderson, Ralph W. Rogers, Jr., William D. Vernam
Estimating the term…
An improved automotive bumper or bumper back-up bar is provided in an aluminum alloy containing selected amounts of zinc and magnesium with a small amount of zirconium and copper, with small amounts of chromium and manganese being optional but preferred. Copper is included to enhance strength. The alloy can contain 5.5-9% Zn, 0.8-2% Mg, 0.11-0.25% Cu, 0.05-0.2% Zr, and preferably 0.05-0.35% Mn or 0.05-0.25% Cr, or both. The alloy products contemplated include shaped sheet and extrusion bumper products. The improved method contemplates homogenization at a controlled temperature and control of subsequent thermal exposure to, in cooperation with the homogenization, assure good performance from the standpoint of both strength and resistance to stress corrosion cracking.
In the production of an improved automotive bumper, the steps comprising
In the production of an improved aluminum bumper beam member wherein an aluminum alloy workpiece is shaped into a bumper beam section by operations which include metal working at temperatures of 750.degree.F or less or at room temperature after annealing at 600.degree.-800.degree.F and wherein said bumper beam section is thereafter solution heat treated and artificially aged, the improvement wherein said aluminum is provided as an alloy consisting essentially of 5.5-9% Zn, 0.8-2% Mg, 0.11-0.25% Cu, 0.05-0.2% Zr, balance essentially aluminum, and said alloy body is homogenized at a temperature of 800.degree.-900.degree.F.
In the production of an improved aluminum bumper beam member wherein an aluminum alloy workpiece is shaped into a bumper which is solution heated, quenched and artificially aged, the improvement wherein said aluminum alloy is provided as an alloy consisting essentially of 5.5-9% Zn, 0.8-2% Mg, 0.11-0.25% Cu, 0.08-0.15% Zr, 0.05-0.35% Mn, 0.05-0.30% Cr, balance essentially aluminum and incidental elements and impurities and said body is homogenized at a temperature of 800.degree.-900.degree.F and further wherein portions of said shaping occur at elevated temperatures of 600.degree.-750.degree.F or at room temperature following annealing at 600.degree.-800.degree.F.
Dependencies are inferred from the claim text.