An age-hardening copper-base alloy and processing method to make a commercially useful strip product for applications requiring high yield strength and moderately high electrical conductivity, in a strip, plate, wire, foil, tube, powder or cast form. The alloys are particularly suited for use in electrical connectors and interconnections. The alloys contain Cu-Ti-X where X is selected from Ni, Fe, Sn, P, Al, Zn, Si, Pb, Be, Mn, Mg, Ag, As, Sb, Zr, B, Cr and Co. and combinations thereof. The alloys offer excellent combinations of yield strength, and electrical conductivity, with excellent stress relaxation resistance. The yield strength is at least of 724 MPa (105 ksi) and the electrical conductivity is at least 50% IACS.