<p>Our group has developed age–hardenable Cu–Ni–Al alloys with excellent tensile strength of over 1400 MPa, excellent discoloration resistance, and non–magnetism, which are useful for leaf springs in Voice Coil Motor (VCM) modules of smartphone cameras. The alloys are fabricated by aging, severe cold rolling, and the final annealing process. There are two unique phenomena in the fabrication processing：One is softening in severe cold rolling and the other is significant hardening in the final annealing. In this study, we attempted to elucidate the softening and hardening mechanism by revealing microstructural changes during the processing via conductivity measurements, and TEM, XRD, and 3DAP tomography analysis. Fine Ni₃Al particles with an fcc ordered structure were dispersed in the Cu matrix after aging. Not only the Cu matrix, but also the Ni₃Al particles were sheared and deformed by severe cold rolling. It was also confirmed that the ordering degree of Ni₃Al particles was reduced by severe cold rolling. The Ni₃Al particles did not change significantly in size and morphology after the final annealing, but their ordering degree was partially restored. Therefore, it can be proposed that the disordering of Ni₃Al particles causes to degradation of age–precipitation strengthening and to softening by severe cold rolling. The significant hardening by the final annealing should be caused by the recovery of ordering degree of Ni₃Al particles.</p>