| 摘要 |
PROBLEM TO BE SOLVED: To provide a composite material of aluminum alloys superior in resistance to pitting corrosion. SOLUTION: The composite material 1 of aluminum alloys has a skin material 3 made from an Al alloy, which is formed on at least one side of a core 2 made from an Al alloy. The skin material 3 comprises, by mass%, 0.03% to 0.3% Fe, 0.4% to 1.9% Mn, 0.4% to 1.4% Si, 2.0% to 5.5% Zn, more than 0% but 0.5% or less Cu, and the balance Al with unavoidable impurities. In a sectional image of the skin material 3 observed with an electron microscope, the maximum size of Al-Mn-based and Al-Cu-based intermetallic compounds precipitated in the skin material 3 shall be 50 nm to 1μm by an circle-equivalent diameter, the number density of the Al-Mn-based and Al-Cu-based intermetallic compounds having the circle-equivalent diameters of 50 nm to 1μm shall be 10 to 150 pieces/100μm<SP>2</SP>, and the area rate of the Al-Mn-based and Al-Cu-based intermetallic compounds having the circle-equivalent diameters of 50 nm to 1μm shall be 1% or less. COPYRIGHT: (C)2009,JPO&INPIT
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