ALUMINUM ALLOY EXTRUSION MATERIAL HAVING EXCELLENT AXIAL COLLAPSE CHARACTERISTIC AND PRODUCTION METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide an aluminum alloy extrusion material which has excellent axial collapse characteristics and corrosion resistance, and is suitable as an energy absorption member, and a production method therefor.;SOLUTION: The extrusion material of an aluminum alloy has a composition containing 0.4 to 0.8% Mg and 0.3 to 0.9% Si, and in which Cu as impurities is controlled to ≤0.05%, and the total content of Mn, Cr and Zr is controlled to ≤0.095%, and the balance Al with inevitable impurities, and is subjected to aging treatment. In the extruding direction, Mg₂Si crystallized products having a length of ≥3 μm are present in ≥50 pieces/mm². A billet of the aluminum alloy having the above composition is subjected to homogenizing treatment at 500°C for ≤20 hr, and is thereafter hot-extruded at 400 to 490°C, or is hot-extruded at 400 to 490°C without undergoing homogenizing treatment, and is subjected to press quenching of performing water cooling or air cooling directly after the extrusion, so that the extrusion material is produced.;COPYRIGHT: (C)2002,JPO