Anisotropic response in mechanical behavior of additively manufactured Al-Mn-Sc alloys by in-situ EBSD tensile tests

The anisotropic of microstructure for additively manufactured Al alloys is attributed to sharp temperature gradient during laser melting, resulting in anisotropy of mechanical properties. The correlation of grain orien-tation, size and aspect ratio on mechanical properties were investigated using in-situ EBSD tensile method on selective laser melting Al-Mn-Sc alloys in longitudinal section and cross section. The lattice rotation behavior and the effects of grain orientation, grain size and aspect ratio on mechanical anisotropy were explored. The predominant <001> orientation of the columnar crystals in the longitudinal section and the <102 > and <101> orientation that dominates the equiaxed crystals in the cross-section had a certain influence on the anisotropy of mechanical properties. The grains with different shapes and sizes exhibited different rotation behavior, and lattice rotation of equiaxed crystals with smaller grain sizes was more complex. By introducing anisotropy co-efficients (Ka), the anisotropy sensitivity to grain orientations was revealed. Based on the anisotropy coefficient, grain size and aspect ratio, the mechanical anisotropy in both directions was accurately predicted.

Automated summary

This study investigated the correlation between grain orientation, size, and aspect ratio and mechanical properties in selectively laser melted Al-Mn-Sc alloys using in-situ EBSD tensile method. The results showed that grain orientation and size influenced the mechanical anisotropy, and mechanical anisotropy was accurately predicted by introducing an anisotropy coefficient.