Electrical connection element

Abstract

Electrical connection element containing a copper-zinc alloy. The copper-zinc alloy comprises (in percent by weight): 28.0 to 36.0% Zn, 0.5 to 1.5% Si, 1.5 to 2.5% Mn, 0.2 to 1.0% Ni, 0.5 to 1.5% Al, 0.1 to 1.0% Fe, optionally also up to a maximum of 0.1% Pb, optionally also up to a maximum of 0.1% P, optionally up to a maximum of 0.08% S, the remainder being Cu and inevitable impurities. According to the invention, mixed silicides containing iron, nickel and manganese are incorporated in the matrix. The structure comprises an α-matrix, which contains inclusions of β-phase from 5 up to 45 percent by volume and of mixed silicides containing iron, nickel and manganese up to 20 percent by volume. The structure further comprises mixed silicides containing iron, nickel and manganese having a stemmed shape and iron and nickel enriched mixed silicides having a globular shape.

1 . An electrical connection element containing a copper-zinc alloy consisting of (in % by weight):
 from 28.0 to 36.0% of Zn,   from 0.5 to 1.5% of Si,   from 1.5 to 2.5% of Mn,   from 0.2 to 1.0% of Ni,   from 0.5 to 1.5% of Al,   from 0.1 to 1.0% of Fe,   optionally up to not more than 0.1% of Pb,   optionally up to not more than 0.1% of P,   optionally up to 0.08% of S,   balance Cu and unavoidable impurities,   characterized
 in that iron-nickel-manganese-containing mixed silicides are embedded in the matrix, 
 in that the microstructure consists of an α matrix in which inclusions of β phase in a proportion of from 5 to 45% by volume and of iron-nickel-manganese-containing mixed silicides in a proportion of up to 20% by volume are present, 
 in that the iron-nickel-manganese-containing mixed silicides having a rod-like form and iron-nickel-enriched mixed silicides having a globular shape are present in the microstructure. 
   
     
     
         2 . The electrical connection element as claimed in  claim 1 , characterized by:
 from 30.0 to 36.0% of Zn,   from 0.6 to 1.1% of Si,   from 1.5 to 2.2% of Mn,   from 0.2 to 0.7% of Ni,   from 0.5 to 1.0% of Al,   from 0.3 to 0.5% of Fe.   
     
     
         3 . The electrical connection element as claimed in  claim 2 , characterized by:
 from 33.5 to 36.0% of Zn.   
     
     
         4 . The electrical connection element as claimed in  claim 1 , characterized in that the electrical conductivity of the alloy is at least 5.8 MS/m. 
     
     
         5 . The electrical connection element as claimed in  claim 4 , characterized in that the electrical conductivity of the alloy is at least 10 MS/m. 
     
     
         6 . The electrical connection element as claimed in  claim 5 , characterized in that the electrical conductivity of the alloy is at least 13 MS/m. 
     
     
         7 . The electrical connection element composed of a copper-zinc alloy as claimed in  claim 1 , characterized in that the microstructure consisting of an α matrix in which inclusions of β phase in a proportion of from 5 to 45% by volume and of iron-nickel-manganese-containing mixed silicides in a proportion of up to 20% by volume are present has been formed after a further treatment comprising at least one hot forming and/or cold forming step and optionally further heat treatment steps. 
     
     
         8 . The electrical connection element composed of a copper-zinc alloy as claimed in  claim 7 , characterized in that the alloy has gone through the following steps during its further treatment:
 extrusion or hot rolling in the temperature range from 600 to 800° C.,   at least one cold forming step.   
     
     
         9 . The electrical connection element composed of a copper-zinc alloy as claimed in  claim 7 , characterized in that the alloy has gone through the following steps during its further treatment:
 extrusion or hot rolling in the temperature range from 600 to 800° C.,   a combination of at least one cold forming step and at least one heat treatment in the temperature range from 250 to 700° C.   
     
     
         10 . The electrical connection element composed of a copper-zinc alloy as claimed in  claim 8 , characterized in that, during the further treatment, the forming is followed by at least one annealing heat treatment in the temperature range from 250 to 450° C.