EFFECT OF PRECIPITATION HARDENING ON DYNAMIC STRAIN AGING AND JERKY FLOW

Strain-rate sensitivity measurements were performed over a wide temperature range in commercial, precipitation hardened Ni and Al alloys. The results indicate that the dynamic strain-aging mechanism is not strongly affected by the presence of a precipitate dispersion. However, since precipitates influence the development of Luders type bands as well as the work hardening rate and other metallurgical variables, the critical strain for the onset of jerky flow is influenced. Therefore, the behavior of the critical strain cannot always be used to examine different theories for the origin of the negative strainrate dependence of the flow stress which develops during straining and is a necessary (but not sufficient) condition for jerky flow. © 1979 The Metallurgical of Society of AIME.