Differences in Deformation Behaviors Caused by Microband-Induced Plasticity of [001]- and [111]-Oriented Austenite Micro-Pillars

A uniaxial compression test and scanning/transmission electron microscopy observations were performed to investigate the differences in mechanical behavior and deformed microstructure between focused ion beam-manufactured [1 1 1]- and [0 0 1]-oriented austenite micro-pillars with 5 mu m diameter from duplex stainless steel. After yielding, the strain hardening of two orientation micro-pillars increased sharply as a result of the formation of a microband, namely microband-induced plasticity, MBIP. The same phenomenon could be observed in a [0 0 1]-oriented pillar due to the activation of the secondary slip system, while slight strain hardening behavior was observed in the [1 1 1] orientation because of the refinement of the microband. Furthermore, the trend of the calculated strain hardening rates of both [1 1 1]- and [0 0 1]-oriented micro-pillars were in good agreement with the experimental data. This study proved that MBIP can be helpful for the mechanical property enhancement of steels.

Automated summary

The study investigated the mechanical behavior and deformed microstructure differences between [1 1 1]- and [0 0 1]-oriented austenite micro-pillars in duplex stainless steel manufactured by focused ion beam. It was found that the strain hardening behavior was different in the two orientations, with the formation of a microband and activation of the secondary slip system playing key roles. The calculated strain hardening rates of both orientations were in good agreement with experimental data, indicating that microband-induced plasticity could enhance the mechanical properties of steels.