Effect of prior deformation on internal friction in a FeNi based austenitic alloy

Effect of prior deformation on strain amplitude-dependent internal friction has been studied in a FeNi based austenitic alloy subjected to solution and peak-aged treatment. The internal friction initially shows increase and then decreases with pre-strain increase in solution-treated alloy. Nevertheless, it is interesting to find that the internal friction shows continued increase with prior deformation degree in peak-aged alloy. Results could be explained using the breakaway model of dislocation in both state alloys. The discrepancy of internal friction behavior, correlated to dislocation arrangement observation, is discussed in terms of slip mode transition from wavy slip to planar slip with introduction of coherent precipitation particles.

► The internal friction (IF) increases initially and then decreases with prior deformation degree in solution treatment alloy.
► The IF shows continued increase with prior deformation degree in austenitic alloy containing coherent precipitation particle, an experimental phenomenon not reported before.
► The dislocation slip mode transition may be related to the discrepancy of IF behavior.