New high pressure die casting aluminum alloy for high temperature and corrosive applications

Abstract

Copper-free aluminum alloys suitable for high pressure die casting and capable of age-hardening under elevated temperatures. The alloy includes about 7-15 wt % silicon, about 0 to 0.6 wt % magnesium, about 0 to 1.0 wt % iron, about 0 to 1.0 wt % manganese, about 0 to 1.0 wt % zinc, about 0 to 0.1 wt % strontium, about 0 to 0.5 wt % titanium, about 0 to 0.5 wt % zirconium, about 0 to 0.5 wt % vanadium, about 0 to 0.5 wt % copper, and about 0 to 1.0 wt % nickel, with a balance of aluminum. Methods for making high pressure die castings and castings manufactured from the alloy.

What is claimed: 
     
         1 . An aluminum alloy suitable for high pressure die casting and capable of temperature-elevated age-hardening, the alloy comprising:
 at least about 78 weight percent aluminum (Al);   about 7 to about 15 weight percent silicon (Si);   about 0 to about 0.6 weight percent magnesium (Mg);   about 0 to about 1 weight percent iron (Fe);   about 0 to about 1 weight percent manganese (Mn);   about 0 to about 1.0 weight percent zinc (Zn);   about 0 to about 0.1 weight percent strontium (Sr);   about 0 to about 0.5 weight percent titanium (Ti); and   about 0 to about 0.5 weight percent zirconium (Zr).   
     
     
         2 . The alloy according to  claim 1 , further comprising:
 about 0 to about 0.5 weight percent vanadium (V).   
     
     
         3 . The aluminum alloy according to  claim 1 , the alloy comprising;
 about 13 weight percent silicon (Si);   about 0.4 weight percent magnesium (Mg);   about 0.4 weight percent iron (Fe);   about 0.8 weight percent manganese (Mn);   about 0.5 weight percent zinc (Zn);   about 0.04 weight percent strontium (Sr);   about 0.3 weight percent titanium (Ti);   about 0.15 weight percent zirconium (Zr); and   a balance of aluminum (Al).   
     
     
         4 . The aluminum alloy according to  claim 2 , the alloy comprising;
 about 8.5 weight percent silicon (Si);   about 0.4 weight percent magnesium (Mg);   about 0.4 weight percent iron (Fe);   about 0.5 weight percent manganese (Mn);   about 0.5 weight percent zinc (Zn);   about 0.04 weight percent strontium (Sr);   about 0.3 weight percent titanium (Ti);   about 0.3 weight percent zirconium (Zr);   about 0.3 weight percent vanadium (V); and   a balance of aluminum (Al).   
     
     
         5 . The alloy according to  claim 1 , further comprising:
 about 0 to about 0.5 weight percent copper (Cu); and   about 0 to about 1 weight percent nickel (Ni).   
     
     
         6 . A high pressure die cast article, cast from an aluminum alloy according to  claim 1 . 
     
     
         7 . The cast article according to  claim 6  having undergone age-hardening at elevated temperature. 
     
     
         8 . The cast article according to  claim 6 , wherein the cast article undergoes a solution heat treatment for a time from about 5 minutes to about 25 minutes. 
     
     
         9 . The cast article according to  claim 7 , exhibiting corrosion of less than about 0.1 mm/year. 
     
     
         10 . The cast article according to  claim 7 , wherein age-hardening conditions comprise an effective temper, T6, or T7 treatments. 
     
     
         11 . The cast article according to  claim 7 , wherein the cast article being as-cast, age-hardened by a temper T5 treatment, or age-hardened by a temper T5 treatment and then soaked at 200° C. for 200 hours and tested at 200° C. exhibits a yield strength above about 150 MPa, ultimate tensile strength above about 190 MPa, and strain above about 1.8 percent. 
     
     
         12 . The cast article according to  claim 10 , wherein the cast article is solution-treated at a temperature around 500° C. 
     
     
         13 . An aluminum alloy suitable for high pressure die casting and capable of age-hardening, the alloy consisting essentially of:
 at least about 78 to about 90 weight percent aluminum (Al);   about 7 to about 15 weight percent silicon (Si);   about 0 to about 0.6 weight percent magnesium(Mg);   about 0 to about 1 weight percent iron (Fe);   about 0 to about 1 weight percent manganese (Mn);   about 0 to about 1.0 weight percent zinc (Zn);   about 0 to about 0.1 weight percent strontium (Sr);   about 0 to about 0.5 weight percent titanium (Ti);   about 0 to about 0.5 weight percent zirconium (Zr);   about 0 to about 0.5 weight percent vanadium (V);   about 0 to about 0.5 weight percent copper (Cu); and   about 0 to about 1 weight percent nickel (Ni).   
     
     
         14 . A high pressure die cast article, cast from an aluminum alloy according to  claim 13 . 
     
     
         15 . The cast article according to  claim 14  exhibiting a casting microstructure comprising at least one or more insoluble solidified and/or precipitated particles with at least one alloying element selected from the group consisting of Al, Si, Mg, Fe, Mn, Zn, Sr, Ti, Zr, V, Cu, Ni. 
     
     
         16 . A method of manufacturing a high pressure die casting of an aluminum alloy, the method comprising:
 providing a molten aluminum alloy comprising:
 at least about 78 weight percent aluminum (Al); 
 about 7 to about 15 weight percent silicon (Si); 
 about 0 to about 0.6 weight percent magnesium (Mg); 
 about 0 to about 1 weight percent iron (Fe); 
 about 0 to about 1 weight percent manganese (Mn); 
 about 0 to about 1.0 weight percent zinc (Zn); 
 about 0 to about 0.1 weight percent strontium (Sr); 
 about 0 to about 0.5 weight percent titanium (Ti); and 
 about 0 to about 0.5 weight percent zirconium (Zr); 
   casting the molten aluminum alloy into a die under high pressure;   solidifying the alloy in the die to form the casting;   cooling the casting in the die to a quenching temperature;   quenching the casting in a quenching solution; and   subjecting the casting to at least one age-hardening treatment.   
     
     
         17 . The method according to  claim 16 , wherein the casting exhibits corrosion of less than about 0.1 mm/year. 
     
     
         18 . The method according to  claim 16 , wherein the casting being as-cast, age-hardened by a temper T5 treatment, or age-hardened by a temper T5 treatment and then soaked at 200° C. for 200 hours and tested at 200° C. exhibits a yield strength above about 150 MPa, ultimate tensile strength above about 190 MPa, and strain above about 1.8 percent. 
     
     
         19 . The method according to  claim 16 , wherein the casting is subject to solution heat treatment for a time from about 5 minutes to about 25 minutes. 
     
     
         20 . A method of manufacturing a high pressure die casting of an aluminum alloy, the method comprising:
 providing a molten aluminum alloy consisting essentially of at least about 78 to about 90 weight percent aluminum (Al), about 7 to about 15 weight percent silicon (Si), about 0 to about 0.6 weight percent magnesium (Mg), about 0 to about 1 weight percent iron (Fe); about 0 to about 1 weight percent manganese (Mn), about 0 to about 1.0 weight percent zinc (Zn), about 0 to about 0.1 weight percent strontium (Sr), about 0 to about 0.5 weight percent titanium (Ti), about 0 to about 0.5 weight percent zirconium (Zr), about 0 to about 0.5 weight percent vanadium (V), about 0 to about 0.5 weight percent copper (Cu), and about 0 to about 1 weight percent nickel (Ni);   casting the molten aluminum alloy into a die under high pressure;   solidifying the alloy in the die to form the casting;   cooling the casting still in the die to a quenching temperature;   quenching the casting in a quenching solution; and   subjecting the casting to a T5 age-hardening treatment, wherein the casting exhibits corrosion of less than about 0.1 mm/year and exhibits a yield strength above about 150 MPa, ultimate tensile strength above about 190 MPa, and strain above about 1.8 percent after the casting is soaked at 200° C. for 200 hours and tested at 200° C.