Aluminum die casting alloy, aluminum die cast product and production process

Abstract

An aluminum alloy for die casting, contains, in terms of mass percentage: Si in the range of 1.0˜3.5 %; Mg in the range of 2.5˜4.5 %; Mn in the range of 0.3˜1.5%; Fe in the range equal to or less than 0.15%; Ti in the range of equal to or less than 0.20%; and the balance of aluminum and inevitable impurities. A die cast product having good strength and elongation in a high strain rate region is produced from the aluminum alloy without the need for solution heat treatment.

What is claimed is:  
     
         1 . An aluminum alloy for die casting, comprising, in terms of mass ratio: 
 silicon in the range of 1.0˜3.5%;    magnesium in the range of 2.5˜4.5%;    manganese in the range of 0.3˜1.5%;    iron in the range equal to or less than 0.15%;    a further constituent comprising titanium in the range of equal to or less than 0.20%; and    the balance of aluminum and inevitable impurities.    
     
     
         2 . The aluminum alloy as claimed in  claim 1 , wherein the further constituent consists of titanium, and the aluminum alloy consists essentially, in terms of mass ratio, of: 
 silicon in the range of 1.0˜3.5%;    magnesium in the range of 2.5˜4.5%;    manganese in the range of 0.3˜1.5%;    iron in the range equal to or less than 0.15%;    titanium in the range of equal to or less than 0.20%; and    the balance of aluminum and inevitable impurities.    
     
     
         3 . The aluminum alloy as claimed in  claim 2 , wherein the Ti content is 0.10% or more.  
     
     
         4 . The aluminum alloy as claimed in  claim 1 , wherein the further constituent consists of titanium and boron, and the aluminum alloy consists essentially, in terms of mass ratio, of: 
 silicon in the range of 1.0˜3.5%;    magnesium in the range of 2.5˜4.5%;    manganese in the range of 0.3˜1.5%;    iron in the range equal to or less than 0.15%;    titanium in the range of 0.05˜0.20%;    boron in the range of 0.001˜0.10%; and    the balance of aluminum and inevitable impurities.    
     
     
         5 . The aluminum alloy as claimed in  claim 1 , wherein the further constituent consists of titanium and zirconium, and the aluminum alloy consists essentially, in terms of mass ratio, of 
 silicon in the range of 1.0˜3.5%;    magnesium in the range of 2.5˜4.5%;    manganese in the range of 0.3˜1.5%;    iron in the range equal to or less than 0.15%;    titanium in the range equal to or smaller than 0.20%;    zirconium in the range of 0.05˜0.30%; and    the balance of aluminum and inevitable impurities.    
     
     
         6 . The aluminum alloy as claimed in  claim 1 , wherein the Mn content is equal to or more than 1.0%.  
     
     
         7 . The aluminum alloy as claimed in  claim 1 , wherein the Si content is equal to or more than 2.5%.  
     
     
         8 . The aluminum alloy as claimed in  claim 1 , wherein the Si content is equal to or less than 2.0%.  
     
     
         9 . The aluminum alloy as claimed in  claim 1 , wherein a ratio of the Mg content in mass %, to the Si content in mass % is equal to or smaller than 2.0.  
     
     
         10 . The aluminum alloy as claimed in  claim 1 , wherein a ratio of the Mg content in mass %, to the Si content in mass % is equal to or greater than 1.8.  
     
     
         11 . A product comprising an aluminum die casting of the aluminum alloy as claimed in  claim 1 .  
     
     
         12 . The product as claimed in  claim 11 , wherein the product is a part of a motor vehicle.  
     
     
         13 . A production process comprising: 
 preparing an aluminum alloy comprising, in terms of mass ratio, 
 silicon in the range of 1.0˜3.5%,  
 magnesium in the range of 2.5˜4.5%,  
 manganese in the range of 0.3˜1.5%,  
 iron in the range equal to or less than 0.15%,  
 a further constituent comprising titanium in the range equal to or less than 0.20%, and  
 the balance of aluminum and inevitable impurities; and  
   forming the aluminum alloy into a fixed shape by die casting operation.    
     
     
         14 . The production process as claimed in  claim 13 , wherein the die casting is vacuum die casting.  
     
     
         15 . The production process as claimed in  claim 13 , wherein a ratio of the Mg content in mass % to the Si content in mass % of the aluminum alloy is equal to or greater than 1.8; and the production process further comprises heat-treating a die-casting obtained by the die casting operation, in the temperature range of 130° C.˜300° C. after the die casting operation.  
     
     
         16 . The production process as claimed in  claim 15 , wherein the operation of heat-treating is one of an artificial aging operation and a stabilizing operation.  
     
     
         17 . The production process as claimed in  claim 15 , wherein the operation of heat-treating comprises at least one of an annealing operation, and a baking operation of baking a coating layer.  
     
     
         18 . The production process as claimed in  claim 13 , wherein a ratio of the Mg content in mass % to the Si content in mass % of the aluminum alloy is equal to or smaller than 2.0; and the production process further comprises stabilizing treatment in the temperature range of 150° C.˜400° C. of stabilizing a die-casting obtained by the die casting operation.  
     
     
         19 . A product comprising an aluminum die casting produced by the production process as claimed in  claim 13 .  
     
     
         20 . The product as claimed in  claim 19 , wherein the product is one of A pillar, B pillar, C pillar, roof, space frame node, and fitting for suspension of a motor vehicle.  
     
     
         21 . The product as claimed in  claim 19 , wherein the product is one of suspension arm, sub-frame and link for suspension.