Effect of Alloying Element Segregations on the Grain Boundary Sliding in Al–Mg and Al–Ni Alloy Bicrystals: Atomistic Modeling

Segregation and grain boundary sliding were studied using atomistic modeling methods for special Σ5{013}〈100〉 and Σ5{012}〈100〉 grain boundaries in Al–3 at % Mg and Al–3 at % Ni alloys bicrystals. To reveal the mechanisms controlling the sliding processes, the energy of generalized grain boundary stacking faults (GB-SF) was determined in the plane of grain boundaries, the crystallography of grain boundary shears was analyzed, and the preferable directions and energy barrier of grain boundary sliding were established. It was shown that alloying with Mg and Ni essentially modified the GB-SF energy, increasing the resistance to sliding.