Aluminum alloy for automobile wheels, and automobile wheel

Abstract

An aluminum alloy for automobile wheels which contains Si in a range of 8.0% to 11.5% by mass, Cu in a range of 0.7% to 1.2% by mass, Mg in a range of 0.2% to 0.6% by mass, Mn in a range of 0.30% to 0.60% by mass, Fe in a range of 0.10% to 0.30% by mass, Cr in a range of 0.01% to 0.03% by mass, and balance Al with inevitable impurities. The aluminum alloy does not contain, per 1182 μm 2 , two or more crystallized products containing 1% by mass or more of Cu and having a circle equivalent diameter exceeding 5 μm, does not contain, per 1182 μm 2 , two or more Cr-containing intermetallic compounds having a length of 8 μm or more, and does not contain, per 4726 μm 2 , two or more primary crystal Si particles having a circle equivalent diameter exceeding 10 μm.

1 . An aluminum alloy for automobile wheels containing Si in a range of 8.0% by mass or more and 11.5% by mass or less, Cu in a range of 0.7% by mass or more and 1.2% by mass or less, Mg in a range of 0.2% by mass or more and 0.6% by mass or less, Mn in a range of 0.30% by mass or more and 0.60% by mass or less, Fe in a range of 0.10% by mass or more and 0.30% by mass or less, Cr in a range of 0.01% by mass or more and 0.03% by mass or less, and balance Al with inevitable impurities, wherein
 the aluminum alloy does not contain, per 1182 μm 2 , two or more crystallized products containing 1% by mass or more of Cu and having a circle equivalent diameter exceeding 5 μm,   the aluminum alloy does not contain, per 1182 μm 2 , two or more Cr-containing intermetallic compounds having a length of 8 μm or more, and   the aluminum alloy does not contain, per 4726 μm 2 , two or more primary crystal Si particles having a circle equivalent diameter exceeding 10 μm.   
     
     
         2 . The aluminum alloy for automobile wheels according to  claim 1 , wherein
 an average particle size of eutectic Si particles is in a range of 0.5 μm or more and 4 μm or less, and an area ratio of the eutectic Si particles is 8% or more.   
     
     
         3 . An automobile wheel formed of the aluminum alloy for automobile wheels according to  claim 1 . 
     
     
         4 . The automobile wheel according to  claim 3 , wherein the automobile wheel is a forged product. 
     
     
         5 . The aluminum alloy for automobile wheels according to  claim 1 , wherein the aluminum alloy contains Si in a range of 8.5% by mass or more and 10.5% by mass or less, Cu in a range of 0.8% by mass or more and 1.1% by mass or less, and Mg in a range of 0.4% by mass or more and 0.6% by mass or less.