Aluminum Alloy For Die Casting, And A Method For Producing A Cast Product Using The Aluminum Alloy

Abstract

An aluminum alloy suitable for obtaining a die-cast aluminum product having high strength and high toughness, comprises, by mass, Si: 7.0 to 9.0%, Mg: 0.4 to 0.6%, Cu: 0.4 to 0.7%, Cr: 0.5% or less, Mn: 0.5% or less, [Cr+Mn]: 0.1 to 0.8%, Fe: 0.10 to 0.25%, and Sr: 0.005 to 0.02%, the balance being Al and impurities.

What is claimed is: 
     
         1 . An aluminum alloy for die casting, comprising, by mass, Si: 7.0 to 9.0%, Mg: 0.4 to 0.6%, Cu: 0.4 to 0.7%, Cr: 0.5% or less, Mn: 0.5% or less, [Cr+Mn]: 0.1 to 0.8%, Fe: 0.10 to 0.25%, and Sr: 0.005 to 0.02%, the balance being Al and impurities. 
     
     
         2 . The aluminum alloy for die casting according to  claim 1 , further comprising 0.2% or less of Ti. 
     
     
         3 . A method for producing a cast product, comprising die-casting the aluminum alloy according to  claim 1 , and filling the aluminum alloy in a laminar flow into a metal mold at an injection gate speed of 1 m/sec or less. 
     
     
         4 . The method for producing a cast product according to  claim 3 , wherein heat treatment is performed at 160° C. to 200° C. for 2 to 8 hours after the die casting. 
     
     
         5 . The method for producing a cast product according to  claim 4 , wherein the cast product has high strength and high toughness with tensile strength of 280 N/mm 2  or more, a 0.2% proof stress of 180 N/mm 2  or more, elongation of 4% or more, and a Charpy impact value of 3 J/cm 2  or more.