| 摘要 |
<p>An aluminum alloy consising essentially of 0.65 to 0.75% by weight of magnesium and 0.50 to 0.60% by weight of silicon or 0.47 to 0.57% by weight of magnesium and 0.75 to 0.85% by weight of silicon, 0.15% to 0.25% by weight of iron, less than 0.05% of an impurity selected from the group consisting of copper, manganese, zinc, chromium, and titanium and the balance aluminum, the aluminum alloy being subjected to aging treatment at a temperature below 200 DEG C for 20 to 50 minutes to obtain 0.2% proof stress larger than 11 kg/mm2, ultimate tensile strength larger than 20 kg/mm2 and elongation more than 8%. Aluminum alloy shapes are formed of the above aluminum alloy by extrusion forming of the aluminum alloy to obtain an extrusion, coating a film on the surface of the extrusion with a water-soluble paint after forming thereon a ground film, heating the extrusion at a temperature below 200 DEG C for 20 to 50 minutes to effect printing and hardening of the coated film and age hardening of the extrusion at the same time.</p> |
