Solid-solution strengthening effects in binary Ni-based alloys evaluated by high-throughput calculations

Abstract

Designing of new alloys requires a detailed understanding of the roles played by each alloying element, yet a systematic investigation of the solid-solution strengthening effects in Ni is still missing. High throughput density functional theory calculations were therefore performed to quantitatively assess the strengthening effects of 35 potential alloying elements from the 2nd to the 6th row of the periodic table in FCC-Ni with varying concentrations. The obtained composition-dependent lattice constants and shear moduli were employed to analyze their strengthening effects within the framework of the Labusch model. It is found that the strengthening ability correlates with the position of the element on the periodic table. Elements in both ends of each period tend to have higher strengthening abilities than those in the middle, and the lattice misfit is found to dominate the strengthening effect for elements in the 5th and 6th period. Stability analysis reveals that all the solid solution models are dynamically stable and intrinsically ductile. Thermodynamic consideration finds that roughly half of the elements are prone to form solid solutions with Ni. By adopting the experimental solubilities, the strengthening potentials of these elements were further evaluated and promising strengthening elements were screened.

Keywords

• Lattice constant
• Shear modulus
• Misfit factor
• Linear regression coefficient
• First-principles calculations