Effect of dynamic strain aging on the deformation behavior and microstructure of Cu-15Ni-8Sn alloy

The compression deformation behavior of the Cu-15Ni-8Sn alloy prepared by powder metallurgy was investigated under a temperature range from 300 to 573 K and a strain rate range of 5 × 10⁻⁵ ∼1 × 10⁻² s⁻¹. The results showed that in a certain range of strain rates and temperatures, the stress-strain curve exhibited obvious serrated flows which were induced by dynamic strain aging (DSA). The activation energy calculations indicated that the DSA was mainly attributed to the interaction of Sn solute atoms with dislocations. In the microstructure of the alloy pre-deformed in the region of DSA, Sn atoms were more likely to aggregated along the slip bands and therefore resulted in the dynamic precipitation of Sn-rich phase at lower temperature than that of natural aging alloy without pre-deformation. - Highlights: • The Cu-15Ni-8Sn alloy exhibits serrated flow in a certain range of strain rates and temperatures. • It can be identified that Sn atoms play major role in the process of DSA. • DSA resulted in the dynamic precipitation of Sn-rich phase at lower temperature. • The DSA and dynamic precipitation may be an important reason for the acceleration of aging.