Process for producing copper-based alloys having high strength and high electric conductivity

摘要

Copper-based alloys suitable for use as materials in fabricating electric and electronic parts as typified by leadframes and having high strength and high electric conductivity can be produced by a process which comprises the steps of preparing a copper-based alloy consisting essentially of 0.01- 3.0 wt % Co and 0.01- 0.5 wt % P with the balance being Cu and incidental impurities, quenching said alloy from a temperature not lower than 750 DEG C. down to 450 DEG C. and below at a cooling rate of at least 1 DEG C./sec, heat treating the quenched alloy at a temperature of 480 DEG -600 DEG C. for 30-600 minutes, cold working said alloy for a working ratio of 20-80%, further heat treating the alloy at a temperature of 440 DEG -470 DEG C. for 30-600 minutes, and subsequently performing cold working for a working ratio of at least 50% and heat treatment at 380 DEG C. and below.