| 摘要 |
PROBLEM TO BE SOLVED: To provide an Al-Mg-Si based alloy extrusion shape material which has excellent bending workability in a T5 material or a T6 material. SOLUTION: The aluminum alloy extrusion profile material has a composition containing, by weight, 0.40 to 0.75% Si and 0.65 to 1.0% Mg so as to satisfy -0.05%<=(Si-Mg/1.73)<=0.20, and further containing 0.02 to <0.05% Mn and 0.02 to <0.05% Zr, and also containing 0.05 to 0.4% Cu, and further containing 0.1 to 0.4% Fe, 0.005 to 0.1% Ti and 0.0001 to 0.004% B, and the balance Al with inevitable impurities. The profile material has a crystal grain structure in which the average grain size in the cross section in the extruding direction of the crystal grains is <=100μm, and also, the ratio between the length in the extruding direction of the crystal grains and the length in the thickness direction is <=2.
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