Phase-Field Simulation of Spinodal Decomposition on Metastable Hexagonal Close-Packed Phase in Magnesium–Yttrium–Zinc Alloy
Year: 2013
Type: article
Abstract: It has been proposed that a long-period stacking ordered (LPSO) structure is responsible for the excellent mechanical properties of lightweight alloys of Mg–Zn–RE (RE: rare earth elements) system. The phase separation of the metastable hexagonal close-packed (hcp) phase in the Mg–Y–Zn alloy was simulated by means of the phase-field method to discuss the mechanism of formation of the LPSO structure. Near the Mg-corner of the Mg–Y–Zn ternary system, metastable spinodal decomposition occurs before conventional spinodal decomposition, i.e., the supersaturated solid solution of Mg–7 at% Y–7 at% Zn alloy separates into two phases: Mg–12 at% Y and Mg–17 at% Zn. The resulting microstructure has a lamellar morphology, elongated along the [0001] direction of the hcp phase, with a wavelength of ∼7 nm. The calculated orientation of the lamellar is completely different from that of the LPSO structure. Therefore, it is difficult to explain the formation of the LPSO structure directly in terms of a spinodal decomposition of the hcp phase in the Mg–Y–Zn ternary system.
Source: MATERIALS TRANSACTIONS
Institution: Nagoya Institute of Technology
Language: English
Subfield: Biomaterials
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1968953716