High-strength and high-toughness aluminum alloy material for bumper beam and method for manufacturing the same

Abstract

The present invention discloses a high strength and high toughness aluminum alloy for a bumper beam and a method for manufacturing the same. The method includes: casting into a billet an aluminum alloy which comprises aluminum as a principal element, silicon (Si) of 0.1 wt. % or less, ferrum (Fe) of 0.2 wt. % or less, copper of 0.45 wt. % to 0.60 wt. %, manganese (Mn) of 0.1 wt. % to 0.20 wt. %, magnesium (Mg) of 1.3 wt. % to 1.5 wt. %, chromium (Cr) of 0.1 wt. % or less, zinc of 4.5 wt. % to 5.1 wt. %, titanium (Ti) of 0.04 wt. % or less, zirconium (Zr) of 0.08 wt. % to 0.12 wt. %, and inevitable impurities of 0.15 wt. % or less; extruding the billet into a predetermined form to form an extrusion; performing a solid-solutionization process to quench the extrusion; subjecting the extrusion to an artificial age-hardening which is performed at a temperature of about 120° C. for 24 hours; and subjecting the extrusion an over age-hardening which is performed at a temperature of about 170° C. to 185° C. for 1 hour to 3 hours.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims the benefit under 35 U.S.C. §119(a) on Korean Patent Application No. 10-2007-0057548 filed on Jun. 13, 2007, the entire contents of which are incorporated herein by reference.BACKGROUND[0002]1. Technical Field[0003]The present invention relates to a high strength and high toughness aluminum alloy suitable for a bumper beam of a vehicle and a method of manufacturing the same.[0004]2. Background Art[0005]Researches on lightweight materials for reducing the weight of a transportation machine such as a vehicle or an aircraft have been undergone for years, and an aluminum alloy has been the most popular material satisfying such a need.[0006]Since an aluminum alloy has high strength and light weight, it is extensively used as a material for a vehicle, an aircraft, etc. or as a material for construction industry.[0007]An aluminum alloy is currently being used in various industrial fields, for example, as electrical and ele...

AI Technical Summary

Benefits of technology

[0022]One aspect of the present invention provides a aluminum alloy material with high-strength and high-toughness, comprising: aluminum as a principal element, silicon (Si) of 0.1 wt. % or less, ferrum (Fe) of 0.2 wt. % or less, copper of 0.45 wt. % to 0.60 wt. %, manganese (Mn) of 0.1 wt. % to 0.20 wt. %, magnesium (Mg) of 1.3 wt. % to 1.5 wt. %, chromium (Cr) of 0.1 wt. % or less, zinc of 4.5 wt. % to 5.1 wt. %, titanium (Ti) of 0.04 wt. % or less, zirconium (Zr) of 0.08 wt. % to 0.12 wt. %, and inevitable impurities of 0.15 wt. % or less.

Problems solved by technology

It is why there is little difference between magnesium (Mg) and zinc (Zn) in solid-solution strengthening effect, and in an alloy that magnesium (Mg) is excessively contained, Al3Mg2 which may be produced according to a heat treatment condition is very harmful to stress corrosion.

However, the high-strength aluminum alloy material of 7000 series still has a problem in that while its elongation is high, its toughness is so low as not to be sufficiently transformed by a crash, which makes the alloy material not suitable for an aluminum bumper beam of a vehicle.

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