Alloying effect on atomic strengthening of binary Ir solid solutions: a first-principles study

摘要

Density functional theory calculations have been performed to systematically study the alloying effect on the atomic strengthening of Ir binary solid solutions. The Mayer bond orders (BOs) were calculated for alloying additions in Ir with 3d, 4d and 5d elements in the periodic table. The trend of the BOs as a function of alloying additions was examined, and then used to assess the alloying effect on Young's moduli of the materials. It was found that the 5d refractory metals Ta, Wand Re increase the BOs significantly and thus could enhance the Young's moduli and hardness. The underlying mechanism for this alloying effect is related to the Mayer total valence electrons of the alloying elements.