Method for manufacturing aluminum alloy exterior material for smart device

A method for manufacturing an aluminum alloy exterior material for smart devices, the method comprising:

• preparing a molten aluminum alloy;
• casting the molten aluminum alloy into a sheet shape using a rotating mold to form an aluminum alloy cast sheet;
• and
• anodizing the aluminum alloy cast sheet, wherein in the forming of an aluminum alloy cast sheet, X in Equation 1 below has a value in a range of greater than 0 to equal to or less than 0.15,
• X=(WZn+WMg+WCu+WSi)/TC(wt %/(W/m·K)) <Equation 1>
• where Wzn is the content (wt %) of the zinc (Zn) in the aluminum alloy, WMg is the content (wt %) of the magnesium (Mg) in the aluminum alloy, WCu is the content (wt %) of the copper (Cu) in the aluminum alloy and WSi is the content (wt %) of the silicon (Si) in the aluminum alloy, and where WZn+WMg+WCu+WSi is the total content (wt %) of the zinc (Zn), magnesium (Mg), copper (Cu) and silicon (Si) in the aluminum alloy, and TC is the thermal conductivity (W/m K) of the rotating mold,
• wherein the aluminum alloy cast sheet comprises a 6000 series aluminum alloy or a 7000 series aluminum alloy,
• wherein the rotating mold comprises a copper twin roll, and
• wherein the copper twin roll has thermal conductivity in a range of 200 W/m·K to 500 W/m·K.