Low-migration copper alloy

Abstract

The present invention relates to a copper alloy, in particular for components which carry media or drinking water, in particular fittings, valves or compression joints and also an advantageous use of the copper alloy and components for lines carrying media or drinking water. It is an object of the present invention to provide a copper alloy which has good corrosion resistance, good castability and mechanical workability and also good mechanical properties and displays good migration values, particularly in respect of the migration of lead and nickel ions into drinking water. The copper alloy provided for this purpose by the present invention comprises from 2% by weight to 4.5% by weight of silicon, from 1 to 15% by weight of zinc and from 0.05% by weight to 2% by weight of manganese. Furthermore, from 0.05 to 0.4% by weight of aluminium and from 0.05 to 2% by weight of tin can optionally be present. As balance, the copper alloy contains copper and unavoidable impurities.

1 . Use of a copper alloy for the manufacture of components for gas or water lines which carry media, in particular drinking water lines as well as fittings and valves of the same, wherein the copper alloy comprises, in % by weight:
 2.8≦Si≦4.5;   1≦Zn≦15;   0.05≦Mn≦2;   80≦Cu≦96.95   
     optionally further comprising;
 0.05≦Al≦0.5 
 0.05≦Sn≦2; 
 0.0005≦Zr≦0.05 
 0.01≦P≦0.2 
 and unavoidable impurities. 
 
   
   
       2 . Use according to  claim 1 , characterized in that the copper alloy is used for the manufacture of compression joints. 
   
   
       3 . Use according to  claim 1 , characterized in that the copper alloy is used for the manufacture of valves with a fixed compression connection. 
   
   
       4 . Use according to  claim 1 , characterized in that 5% by weight≦Zn≦15% by weight. 
   
   
       5 . Use according to one of  claims 1  to  4 , characterized in that 0.2% by weight≦Mn≦0.6% by weight. 
   
   
       6 . Use according to  claim 5 , characterized in that the unavoidable impurities are contained with not more than altogether 0.5% by weight. 
   
   
       7 . Use according to  claim 6 , characterized in that the unavoidable impurities are contained with not more than altogether 0.25% by weight. 
   
   
       8 . Use according to  claim 6  or  7 , characterized in that Ni and/or Pb are contained as unavoidable impurities with not more than altogether 0.25% by weight. 
   
   
       9 . Components for gas or water lines which carry media, in particular drinking water lines as well as fittings and valves of the same, at least partially consisting of a copper alloy, comprising in % by weight:
 2.8≦Si≦4.5;   1≦Zn≦15;   0.05≦Mn≦2;   80≦Cu≦96.95   
     optionally further comprising;
 0.05≦Al≦0.5 
 0.05≦Sn≦2; 
 0.0005≦Zr≦0.05 
 0.01≦P≦0.2 
 and unavoidable impurities. 
 
   
   
       10 . Component according to  claim 9 , characterized in that the elements Cu, Zn and Si are present in an amount of more than 98% by weight in the form of an α-solid solution. 
   
   
       11 . Components according to  claim 9 , characterized in that the components are compression joints. 
   
   
       12 . Components according to  claim 11 , characterized in that the components are valves with fixed compression connection. 
   
   
       13 . Component according to  claims 9  or  11 , characterized in that 5% by weight≦Zn≦15% by weight. 
   
   
       14 . Component according to  claims 9  or  11 , characterized in that 0.2% by weight≦Mn≦0.6% by weight. 
   
   
       15 . Component according to  claim 9 , characterized in that the unavoidable impurities are contained with altogether not more than 0.5% by weight. 
   
   
       16 . Component according to  claim 15 , characterized in that the unavoidable impurities are contained with altogether not more than 0.25% by weight. 
   
   
       17 . Component according to  claim 15 , characterized in that Ni and/or Pb are contained as unavoidable impurities with altogether not more than 0.25% by weight. 
   
   
       18 . Components for gas or water lines which carry media, in particular drinking water lines as well as fittings and valves of the same, at least partially consisting of a copper alloy, comprising in % by weight:
 2.8≦Si≦4.5;   1≦Zn≦15;   0.05≦Mn≦2;   80≦Cu≦96.95   
     optionally further comprising;
 0.05≦Al≦0.5 
 0.05≦Sn≦2; 
 0.0005≦Zr≦0.05 
 0.01≦P≦0.2 
 
     and unavoidable impurities and wherein the elements Cu, Zn and Si are present in an amount of more than 98% by weight in the form of an α-solid solution. 
   
   
       19 . Components according to  claim 18 , characterized in that the components are compression joints. 
   
   
       20 . Components according to claim to  18 , characterized in that the components are valves with fixed compression connection. 
   
   
       21 . Component according to  claim 18 , characterized in that 5% by weight≦Zn≦15% by weight. 
   
   
       22 . Component according to  claim 18 , characterized in that 0.2% by weight≦Mn≦0.6% by weight. 
   
   
       23 . Component according to  claim 18 , characterized in that the unavoidable impurities are contained with altogether not more than 0.5% by weight. 
   
   
       24 . Component according to  claim 23 , characterized in that the unavoidable impurities are contained with altogether not more than 0.25% by weight. 
   
   
       25 . Component according to  claim 18  or  24 , characterized in that Ni and/or Pb are contained as unavoidable impurities with altogether not more than 0.25% by weight.