Aluminum alloy and method for producing same

Abstract

To provide an aluminum alloy in which natural aging is suppressed and a method for producing the same. This disclosure relates to an Al—Si-based aluminum alloy containing Si, Mg, Mn, Fe, and unavoidable impurities and Al—Si—Mg—Fe—Mn-based compounds, and further to a method for producing said Al—Si—based aluminum alloy by controlling the cooling process of a molten alloy during casting.

What is claimed is: 
     
         1 . An Al—Si-based aluminum alloy comprising Si, Mg, Mn, Fe and unavoidable impurities in which the Al—Si-based aluminum alloy comprises Al—Si—Mg—Fe—Mn-based compounds. 
     
     
         2 . The Al—Si-based aluminum alloy according to  claim 1 , in which when the Al—Si-based aluminum alloy is observed by EPMA mapping with a field of 80 μm×80 μm, in the Al—Si—Mg—Fe—Mn-based compounds, positions with a 50% or more intensity of K-α from Mg, positions with a 10% to 20% intensity of K-α from Mn, and positions with a 5% to 14% intensity of K-α from Fe are at a same location with respect to Mg, Mn and Fe, and positions with a 80% or more intensity of K-α from Mn and positions with a 44% or more intensity of K-α from Fe are at a same location with respect to Mn and Fe. 
     
     
         3 . A method for producing an Al—Si-based aluminum alloy, comprising
 (i) a raw material preparation process of preparing raw materials for the Al—Si-based aluminum alloy comprising Si, Mg, Mn, Fe, and unavoidable impurities; 
 (ii) a molten alloy preparation process of heating the raw materials prepared in the raw material preparation process of (i) to prepare a molten alloy; 
 (iii) a pouring process of pouring the molten alloy prepared in the molten alloy preparation process of (ii) into a mold; and 
 (iv) a cooling process of cooling and solidifying the molten alloy poured in the pouring process of (iii), 
 in which the cooling process of (iv) includes a solidification holding process in which the molten alloy is held in a temperature range of 510° C. to 470° C. for 20 minutes to 40 minutes when a temperature of the molten alloy reaches the said temperature range.