The stability of deformation twins in aluminum enhanced by alloying elements

Introducing and stabilizing twins in aluminum is a challenge for metals research due to their high formation energy. Employing first-principles calculations, we investigated the twin boundary segregation of alloying elements and their impact on the twin boundary energy in aluminum. Alloying elements with small solubilities but strong interaction with twin boundary would significantly reduce twin boundary energies in aluminum at low temperatures. With increasing temperature, their segregation near twin boundary weakens, leading to their influence on twin boundary energies reduced. Some elements with large solubilities may greatly reduce the twin energies not only at low temperatures but also at high temperatures. Based on careful analysis of charge density and atomic radius, it has been found that chemical difference has little influence on twin boundary energy whereas the atomic size effect plays a leading role in causing the change of twin boundary energy.