Lubricant-Compatible Copper Alloy

Abstract

The present disclosure relates a copper alloy having a high corrosion resistance for a wide range of different lubricants, in particular different base oils and a variation of lubricant additives. The property of a low corrosion tendency for different tribological systems is also combined with good mechanical properties, and a high strength in particular. Furthermore, the alloy has a low wear and a coefficient of friction. The lubricant-compatible copper alloy is suitable for producing gear components that come in contact with lubricant and are exposed to friction stresses, such as synchronizer rings. A method for manufacturing such gear components and a gear having such gear components is also disclosed.

1 . A lubricant-compatible copper alloy, comprising in % by weight: 
       
         
           
                 
                 
               
                     
                 
                   54-65%  
                   copper 
                 
                   2.5-5.0%     
                   aluminum 
                 
                   1.0-3.0%     
                   silicon 
                 
                   2.0-4.0%     
                   nickel 
                 
                   0.1-1.5%     
                   iron 
                 
                   ≦1.5% 
                   manganese 
                 
                   ≦1.5% 
                   tin 
                 
                   ≦1.5% 
                   chromium 
                 
                   ≦1.5% 
                   cobalt 
                 
                   ≦0.8% 
                   lead 
                 
                   remainder 
                   zinc plus other unavoidable contaminants, 
                 
                     
                 
             
                
               
               
                
                
                
                
                
                
                
                
                
                
                
                
               
            
           
         
         wherein free silicon is present in the alloy matrix or in silicon-containing non-silicide phases in the amount of at least 0.4% and at most 2%, and the weight ratio between zinc and free silicon is 15 to 75; and 
         a β phase is present in an amount greater than 80% and there are no silicon-rich γ phases in the alloy mixture. 
       
     
     
         2 . The copper alloy of  claim 1 , further comprising 3.0-5.0% aluminum, 0.5-1.5% iron and ≦0.7% tin in % by weight. 
     
     
         3 . The copper alloy of  claim 1 , further comprising 56-60% copper, 3.0-4.0% aluminum, 1.3-2.5% silicon, 3.0-4.0% nickel, 0.5-1.5% iron, 0.1-1.5% manganese and 0.3-0.7% tin in % by weight. 
     
     
         4 . The copper alloy according to  claim 1 , containing 59-62% copper, 3.5-4.5% aluminum, 1.2-1.8% silicon, 2.5-3.9% nickel, 0.7-1.1% iron, 0.7-1.0% manganese and 0.05-0.5% tin and ≦0.1% lead. 
     
     
         5 . The copper alloy of  claim 1 , wherein the amount of free silicon is at least 0.65% by weight. 
     
     
         6 . The copper alloy of  claim 1 , wherein the weight ratio between zinc and free silicon is selected to be in the range of 20 to 55. 
     
     
         7 . The copper alloy of  claim 1 , wherein the amount of aluminum exceeds the stoichiometric ratio of the sum of the iron, manganese, nickel and chromium amounts. 
     
     
         8 . The copper alloy of  claim 1 , wherein a ratio of the sum of the elements Ni+Fe+Mn to Si is ≦3.45. 
     
     
         9 . The copper alloy of  claim 1 , wherein lead as an impurity is present in the amount of max. 0.8% by weight in the buildup of the alloy. 
     
     
         10 . A method of producing a workpiece from the copper alloy of  claim 1 , comprising at least one heat treatment step with subsequent cooling such that the amount of free silicon in the matrix or in silicon-containing non-silicide phases corresponds to at least 0.4%. 
     
     
         11 . The method of  claim 10 , wherein process management of the at least one heat treatment step and subsequent cooling creates a β phase content of at least 80%. 
     
     
         12 . The method of  claim 10 , wherein a synchronizer ring for a gear is manufactured from the copper alloy. 
     
     
         13 . A gear containing at least one copper alloy component that is exposed to friction and manufactured from the copper alloy of  claim 1 , said gear comprising a gear casing in which the at least one copper alloy component is arranged in a gear oil environment, said at least one copper alloy component having a reaction layer on a surface which is exposed to friction, with additives present in the gear oil and free silicon present as a reactive element in the matrix or in silicon-containing non-silicide phase or the reaction products and/or decomposition products thereof. 
     
     
         14 . The gear of  claim 13 , wherein the at least one copper alloy component is a synchronizer ring. 
     
     
         15 . The copper alloy of  claim 8 , wherein the ratio is ≦3.25.