Aluminum casting alloy

Abstract

A cast aluminum alloy contains at least five of the following alloy components: 2.5 to 3.3 wt.-% of Si; 0.2 to 0.7 wt.-% of Mg; <0.18 wt.-% of Fe; <0.5 wt.-% of Mn; <0.1 wt.-% of Ti; <0.03 wt.-% of Sr; 0.3 to 1.3 wt.-% of Cr; and <0.1 wt.-% of others, supplemented by Al to add up to 100 wt.-%. The parts cast from the alloy are preferably homogenized by annealing for 1 to 10 hours at 490° C. to 540° C. and tempered for 1 to 10 hours at 150° C. to 200° C. Preferably, the alloy is used for chassis parts in motor vehicles.

1 . An aluminum casting alloy that contains at least five of the alloy components listed below
 Si: 2.5 to 3.3 wt.-%;   Mg: 0.2 to 0.7 wt.-%;   Fe: <0.18 wt.-%;   Mn: <0.5 wt.-%;   Ti: <0.1 wt.-%;   Sr: <0.03 wt.-%;   Other: <0.1 wt.-%   
       wherein Cr in an amount that increases alloy strength is contained as another alloy component, supplemented to 100 wt.-% with Al. 
     
     
         2 . The aluminum casting alloy according to  claim 1 , wherein Si is present in the amount of 2.7 to 3.1 wt.-%. 
     
     
         3 . The aluminum casting alloy according to  claim 1 , wherein Mg is present in the amount of 0.3 to 0.6 wt.-%. 
     
     
         4 . The aluminum casting alloy according to  claim 1 , wherein Fe is present in the amount of 0.05 to 0.16 wt.-%. 
     
     
         5 . The aluminum casting alloy according to  claim 1 , wherein Mn is present in the amount of 0.05 to 0.4 wt.-%. 
     
     
         6 . The aluminum casting alloy according to  claim 1 , wherein Ti is present in the amount of 0.01 to 0.08 wt.-%. 
     
     
         7 . The aluminum casting alloy according to  claim 1 , wherein Sr is present in the amount of 0.01 to 0.03 wt.-%. 
     
     
         8 . The aluminum casting alloy according to  claim 1 , wherein Cr is present in the amount of 0.3 to 1.3 wt.-%. 
     
     
         9 . The aluminum casting alloy according to  claim 1 , wherein Cr is present in the amount of 0.4 to 1.0 wt.-%. 
     
     
         10 . The aluminum casting alloy according to  claim 1 , wherein Cr is present in the amount of 0.5 to 0.8 wt.-%. 
     
     
         11 . The aluminum casting alloy according to  claim 1 , wherein the at least five of the alloy components are present in amounts listed below
 Si: 2.7 to 3.1 wt.-%;   Mg: 0.3 to 0.6 wt.-%;   Fe: 0.05 to 0.16 wt.-%;   Mn: 0.05 to 0.4 wt.-%;   Ti: 0.01 to 0.08 wt.-%;   Sr: 0.01 to 0.03 wt.-%.   
     
     
         12 . An aluminum casting alloy that contains at least five of the alloy components listed below
 Si: 2.5 to 3.3 wt.-%;   Mg: 0.2 to 0.7 wt.-%;   Fe: <0.18 wt.-%;   Mn: <0.5 wt.-%;   Ti: <0.1 wt.-%;   Sr: <0.03 wt.-%;   Cr: 0.3 to 1.3;   Other: <0.1 wt.-%   
       and supplemented to 100 wt.-% with Al. 
     
     
         13 . The aluminum casting alloy according to  claim 12 , wherein the at least five of the alloy components are present in amounts listed below
 Si: 2.7 to 3.1 wt.-%;   Mg: 0.3 to 0.6 wt.-%;   Fe: 0.05 to 0.16 wt.-%;   Mn: 0.05 to 0.4 wt.-%;   Ti: 0.01 to 0.08 wt.-%;   Sr: 0.01 to 0.03 wt.-%;   Cr: 0.4 to 1.0 wt.-%.   
     
     
         14 . The aluminum casting alloy according to  claim 12 , wherein the at least five of the alloy components are present in the amounts listed below
 Si: 2.7 to 3.1 wt.-%;   Mg: 0.3 to 0.6 wt.-%;   Fe: 0.05 to 0.16 wt.-%;   Mn: 0.05 to 0.4 wt.-%;   Ti: 0.01 to 0.08 wt.-%;   Sr: 0.01 to 0.03 wt.-%;   Cr: 0.5 to 0.8 wt.-%.   
     
     
         15 . The aluminum casting alloy according to  claim 12 , wherein in addition, CuNi is contained as an additional alloy component, by being alloyed in at the same time, supplemented to 100 wt.-% with Al. 
     
     
         16 . A method of producing a part comprising
 (a) forming a cast part from an aluminum casting alloy containing at least five of the alloy components listed below   Si: 2.5 to 3.3 wt.-%;   Mg: 0.2 to 0.7 wt.-%;   Fe: <0.18 wt.-%;   Mn: <0.5 wt.-%;   Ti: <0.1 wt.-%;   Sr: <0.03 wt.-%;   Other: <0.1 wt.-%   
       wherein Cr in an amount that increases alloy strength is contained as another alloy component, supplemented to 100 wt.-% with Al; and
 (b) solution-annealing the cast part between 490° C. to 540° C. for 1 to 10 hours. 
 
     
     
         17 . The method according to  claim 16 , wherein the cast part is annealed between 150° C. to 200° C. for 1 to 10 hours. 
     
     
         18 . The method according to  claim 16 , wherein the Al casting alloy is grain-refined. 
     
     
         19 . The method according to  claim 16 , further comprising using the part to form a work piece. 
     
     
         20 . The method according to  claim 16 , further comprising using the part to form a component of a motor vehicle chassis.