Dislocation boundary width changes due to cyclic hardening

Abstract

In this article, cyclic deformations of pure aluminum specimens were characterized by analyzing the cyclic hardening response. Microstructural observations were done by means of transmission electron microscopy (TEM). Microscopic analysis showed that dislocation tangles migrate to the boundary and dislocation boundaries become thinner, condensed, and well defined as plastic strain increases.

Creep and Superplasticity: Evolution and Rationalization

“…Finally, it was predicted that under a combination of experimental conditions and favorable materials parameters, ductility in a solid‐solution alloy should exhibit a maximum at intermediate strain rates (intermediate stresses). Such a prediction was based on two observations: 1) for solid‐solution alloy, the stress exponent decreases from a value of about 5 at low stresses (low strain rates) to a value of about 3 at intermediate stresses (intermediate strain rates) and then to a value higher than 3 at high stresses and 2) ductility is a sensitive function of the stress exponent .…”

On the low-cycle fatigue behavior of thermo-mechanically processed high-strength aluminum alloys

“…Specimens formed in the tool with a temperature of 350 °C exhibit steady cyclic hardening during LCF testing (with the exception of the AA7075 at lowest strain amplitude). This can be attributed to a progressive dislocation generation and dislocation-dislocation as well as dislocation precipitate interactions during cyclic loading, eventually leading to the evolution of dislocation cell structures in between the coarsened precipitates [52,[56][57][58][59]. At this point further in-depth analysis requires assessment of microstructure evolution via transmission electron microscope (TEM), which is beyond the scope of the present study.…”