Abstract: Copper-based alloys containing minor amounts of beryllium, cobalt and/or nickel, and zirconium are subjected to treatment comprising, in sequence: annealing followed by quenching; cold working; a second optional annealing followed again by quenching; a cold working; an initial age hardening treatment; a secondary age hardening treatment; if necessary, straightening the alloy; and stress relieving the straightened alloy. Optimum elevated temperature properties are developed in alloys treated according to the present invention and articles made of the treated alloys are useful under conditions involving high operating speed and elevated temperature.