The study of dislocation dynamics in thermally aged Fe–1%Cu–C alloys by internal friction measurements

The effect of copper precipitation and the role of carbon in the dislocation dynamics of thermally aged Fe–1%Cu–C alloys are studied by measuring the internal friction coefficient of non-deformed and cold-worked samples in the temperature range from 100 to 600 K. In non-deformed samples we observe a complex behaviour of the Snoek-relaxation peak intensity, which indicates the existence of carbon redistribution governed by the copper precipitation. In cold-worked samples, the behaviour of dislocation-related relaxation processes is explained through an increase in hardening due to copper precipitation at early precipitation stages, and through the carbon redistribution which seems to play a major role in the alloy softening at later precipitation stages.