Atomistic Insight into the Texture Weakening and Shear-Shuffle Twinning Mechanism During Cold-Rolling of Magnesium

Basal texture weakening and twinning are two important mechanisms causing enhancement in the formability of nanocrystalline magnesium. However, the atomistic perspective of these mechanisms along with structural evolution during the rolling process is unexplored. Here, we have implemented molecular dynamics simulations and modeled the cold-rolling process to study the dynamic twin nucleation through atomic shuffling and texture weakening mechanisms under the influence of compressive loads. Results show that twinning propagates along the grains under shear stress through twin boundary disconnection steps, whereas successive thickness reduction through multiple passes causes an overall texture weakening due to the RD splitting of basal orientation. Along with this, grain refinement is also found to contribute towards texture weakening. The findings of this work comply well with the experimental results and we hope that it can aid in demystifying the enigma related to structural evolution in nanostructured HCP metals during the rolling process.

Automated summary

This study investigates the effects of basal texture weakening and twin nucleation mechanisms under compressive loads during the cold-rolling process using molecular dynamics simulations. The results show that twinning propagates along the grains through twin boundary disconnection steps, while multiple thickness reductions contribute to overall texture weakening. Grain refinement also plays a role in texture weakening.