Assessing Mg–Sc–(rare earth) ternary phase stability via constituent binary cluster expansions

• The disordered Mg–Sc body-centered cubic (bcc) phase is both lightweight and strong; however, the system is impractical for general industrial use due to the high cost of scandium. We propose a computationally efficient metric that assesses ternary rare earth element additions that may stabilize the bcc phase at lower Sc concentrations. We find that the bcc phase is stabilized by the ternary addition of Y or Er, but not by La, Ce, or Nd, and we validate these predictions by experimental production and characterization of Mg–Sc–(Y,Er,Nd) alloys. The results suggest a computationally efficient method to anticipate integration of ternary elements into binary systems using cluster expansions of constituent binaries.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

Keyword

Magnesium alloys

Neodymium alloys

Rare earth elements

Rare earths

Binary clusters

Body-centered-cubic phase

Cluster expansion

Computationally efficient

High costs

Industrial use

Rare earth metals

Rare-earth metals

Rare-earths

Ternary phasis

Computational efficiency

Publication and Content Type

ref (subject category)

art (subject category)