Copper-zinc alloy, production method and use

Abstract

The invention relates to a copper-zinc alloy, consisting of (in wt %): from 28.0 to 36.0% Zn, from 0.5 to 2.3% Si, from 1.5 to 2.5% Mn, from 0.2 to 3.0% Ni, from 0.5 to 1.5% Al, from 0.1 to 1.0% Fe, optionally also up to at most 0.1% Pb, optionally also up to at most 0.2% Sn, optionally also up, to at most 0.1% P, optionally also up to 0.08% S, remainder Cu and inevitable impurities, with mixed silicides of iron-nickel-manganese incorporated in the matrix.

1 . Copper-zinc alloy, consisting of (in wt %):
 from 28.0 to 36.0% Zn,   from 0.5 to 2.3% Si,   from 1.5 to 2.5% Mn,   from 0.2 to 3.0% Ni,   from 0.5 to 1.5% Al,   from 0.1 to 1.0% Fe,   optionally also up to at most 0.1% Pb,   optionally also up to at most 0.2% Sn,   optionally also up to at most 0.1% P,   optionally also up to 0.08% S,   remainder Cu and inevitable impurities, with mixed silicides of iron-nickel-manganese incorporated in the matrix.   
   
   
       2 . Copper-zinc alloy according to  claim 1 , characterized by:
 from 28.0 to 36.0% Zn,   from 0.5 to 1.5% Si,   from 1.5 to 2.5% Mn,   from 0.2 to 1.0% Ni,   from 0.5 to 1.5% Al,   from 0.1 to 1.0% Fe.   
   
   
       3 . Copper-zinc alloy according to  claim 1 , characterized by:
 from 28.0 to 36.0% Zn,   from 1.0 to 2.3% Si,   from 1.5 to 2.5% Mn,   from 1.5 to 3.0% Ni,   from 0.5 to 1.5% Al,   from 0.1 to 1.0% Fe.   
   
   
       4 . Copper-zinc alloy according to  claim 3 , characterized in that the ratio Mn/Ni of the elementary contents of the elements manganese and nickel lies between 0.7 and 1.3. 
   
   
       5 . Copper-zinc alloy according to  claim 1 , characterized in that in the cast state, the structure comprises a β-phase content of up to 50 vol. %. 
   
   
       6 . Copper-zinc alloy according to  claim 1 , characterized in that after post-processing which involves at least hot forming or cold forming and further annealing steps, the structure comprises a β-phase content of up to 45 vol. %, the mixed silicides of Fe—Ni—Mn up to 20 vol. % and a remainder of α-phase. 
   
   
       7 . Copper-zinc alloy according to  claim 6 , characterized in that the ratio R p0.2 /R m  of the values for the yield point and tensile strength of the alloy lies between 0.5 and 0.95. 
   
   
       8 . Method for producing tubes or rods made of a copper-zinc alloy according to  claim 1 , characterized in that a post-processing of the alloy comprises the following steps:
 extrusion in a temperature range of from 600 to 800° C.,   at least one cold forming.   
   
   
       9 . Method for producing tubes or rods made of a copper-zinc alloy according to  claim 1 , characterized in that a post-processing of the alloy comprises the following steps:
 extrusion in a temperature range of from 600 to 800° C.,   a combination of at least one cold forming with at least one anneal in a temperature range of from 250 to 700° C.   
   
   
       10 . Method for producing tubes or rods made of a copper-zinc alloy according to  claim 8 , characterized in that the forming is followed by a stress-relieving anneal in a temperature range of from 250 to 450° C. 
   
   
       11 . Use of a copper-zinc alloy according to  claim 1  for friction bearing elements in combustion engines, transmissions or hydraulic equipment.