Coherent twin-oriented Al3Sc-based precipitates in Al matrix
S. Shanmugam, M. Peterlechner, M. Iskandar, U. Saikia, V. Kulitckii, M. Lipińska-Chwałek, J. Mayer, H. Rösner, T. Hickel, S. V. Divinski, G. Wilde.
Scripta Materialia, Elsevier BV, 229, 115351, (2023)
Al3(Sc,Zr,Ti) nanoparticles with an ideal twin-type orientation relationship to Al host matrix were found in cold-rolled and subsequently annealed Al-based alloy. Atomic-scale investigations using high-resolution scanning transmission electron microscopy identified particles that form prominent coherent (111) twin-type interfaces along their longer facets and semi-coherent twin interfaces on their shorter facets. Ab-initio calculations showed that a coherent Al/Al3Sc twin-like phase boundary corresponds to a local energy minimum. A model is proposed explaining the formation of the twin orientation relationship of an Al3Sc nanoparticle with the Al host matrix.