Exploring the solution strengthening effect of 33 alloying elements in Pt-based alloys by high-throughput first-principles calculations

Abstract

Pt-based alloys are the candidate for high-temperature materials due to their inoxidizability, but the disadvantage is their low strength. The solution strengthening effect of 33 alloying elements on Pt-based alloys is systematically explored for the first time by means of first-principles calculations in this work. It is found that the strengthening ability of alloying elements (Th, La, Ce, Zr, Hf, Ta, W, Nb, and Y) commonly used in Pt-based alloys is validated. Moreover, the potential alloying elements with a stronger strengthening effect are excavated, e.g., Cr, V, Mn, Mo, Ti, Sc, Tc, and Re. Among them, the strengthening effect of rare elements (RE = Th, La, Ce, and Y) mainly originate from larger lattice misfit, while the other alloying elements gain their high strengthening potentials due to larger modulus misfit caused by larger electronegativity difference between alloying elements (Zr, Hf, Ta, Nb, V, Sc, Tc, and Re) and Pt or higher inherent shear modulus of alloying elements (W, Cr, Mn, and Mo). In addition, the strengthening effect of alloying elements under 1/3 of the absolute melting temperature of Pt is effectively predicted by the Labusch model combined with quasiharmonic approximation and quasistatic approximation. These findings are greatly beneficial to the guidance composition design of the new Pt-based superalloys.