Effect of P Content on Stress Relaxation and Clustering Behavior in Cu-Ni-P Alloys

Stress relaxation behavior and cluster distributions in Cu P alloy and Cu Ni P alloys with different P content have been investigated by means of three dimensional atom probe (3DAP) The overall Improvement in the stress relaxation performance is considered in terms of dislocation pinning by solute atoms and clusters The Cu Ni P alloy with low P content forms a low density of Ni P clusters during annealing and shows a greater improvement in stress relaxation resistance than the Cu P alloy It is shown that the pinning effect of solute P has much less Impact on the stress relaxation behavior in Cu alloys than the effect of the clusters It is demonstrated that the clusters play a key role in the stress relaxation in Cu alloys and that the stress relaxation performance can be related to the volume fraction of the clusters [doi 10 2320/matertrans M2010190].