Al-si alloy for casting, al-si alloy casting and al-si alloy casting joint

Abstract

Provided is an Al—Si alloy for casting which is capable of imparting high yield strength to an Al—Si alloy casting in addition to being capable of effectively suppressing the occurrence of cracking when press-fitting a self-piercing rivet into an aluminum alloy casting. In addition, provided are: an Al—Si alloy casting which has high yield strength and effectively suppresses the occurrence of cracking when press-fitting a self-piercing rivet therein; and an Al—Si alloy casting joint in which said Al—Si alloy casting is the material to be joined. The Al—Si alloy for casting in the present invention is characterized by comprising Si in the amount of 5.0-12.0 mass %, Mn in the amount of 0.4-1.5 mass %, Mg in the amount of 0.05-0.6 mass %, Cr in the amount of 0.1-0.5 mass %, and Fe in an amount greater than 0 and no greater than 0.6 mass %, with the remainder constituting Al and inevitable impurities.

1 . An Al—Si alloy for casting, characterized by comprising:
 5.0 to 12.0% by mass of Si, 
 0.4 to 1.5% by mass of Mn, 
 0.05 to 0.6% by mass of Mg, 
 0.1 to 0.5% by mass of Cr, and 
 more than 0 and not more than 0.6% by mass of Fe, 
 with the balance being Al and inevitable impurities. 
 
     
     
         2 . The Al—Si alloy for casting according to  claim 1 , which comprises one or more of:
 0.05 to 0.5% by mass of Cu, 
 0.005 to 0.03% by mass of Ca, 
 0.001 to 0.02% by mass of B, 
 0.005 to 0.03% by mass of Sr, 
 0.01 to 0.2% by mass of Sb, and 
 0.002 to 0.02% by mass of Na. 
 
     
     
         3 . An Al—Si alloy casting, comprising the Al—Si alloy for casting according to  claim 1 . 
     
     
         4 . The Al—Si alloy casting according to  claim 3 , wherein a limit bending angle in the VDA bending test specified in VDA238-100 is 28° or more. 
     
     
         5 . The Al—Si alloy casting according to  claim 3 , wherein a 0.2% yield strength is 100 MPa or more. 
     
     
         6 . A self-piercing rivet joint, which is a joint joined by using a self-piercing rivet, and characterized in that at least one of joined members is the Al—Si alloy casting according to  claim 3 .