A copper alloy having improved resistance to cracking due to localized
plastic deformation and the process of making it. The alloy consists
essentially of: from 0.7 to 3.5 weight percent nickel; from 0.2 to 1
weight percent silicon; from 0.05 to 1 weight percent tin; from 0.26 to 1
weight percent iron; and the balance copper and unavoidable impurities.
The copper alloy has a local ductility index of greater than 0.7 and a
tensile elongation exceeding 5%. Cobalt may be substituted for iron, in
whole or in part, on a 1:1 basis by weight. The alloy is precipitation
hardenable and useful for electronic applications, including without
limitation, connectors.