Development of Ti–Zr–Hf–Y–La high-entropy alloys with dual hexagonal-close-packed structure
Takeshi Nagase, Mitsuharu Todai, Takayoshi Nakano
Abstract
TiZrHfYLa0.2 high-entropy alloys (HEAs) with dual hexagonal-closed-packed (HCP) structures were designed based on the concept of liquid phase separation (LPS) and segregation for enhancing the immiscibility of the constituent elements. The LPS leads to a particular solidification microstructure on the free surface side and Cu-hearth contacted area in the ingots. The dual HCP structures with equi-axis Ti–Zr–Hf dendrite and Y-La-rich interdendrite were observed at most regions of the arc-melted ingots. The mixing enthalpy among the constituent elements and predicted phase diagrams constructed by the Materials Project were effective for the alloy design of the HEAs with dual HCP structures.
Topics & Concepts
Materials scienceHexagonal crystal systemMicrostructureAlloyHigh entropy alloysClose-packing of equal spheresMetallurgyPhase (matter)EnthalpyCrystallographyThermodynamicsChemistryPhysicsOrganic chemistryHigh Entropy Alloys StudiesHigh-Temperature Coating BehaviorsAdvanced materials and composites