Herein, the effect of calcium (Ca) microalloying on the microstructure and mechanical properties of Mg₉₄Zn_2.5Y_2.5Mn₁ alloy is identified. The long‐period stacking‐ordered (LPSO) phase transformation mechanism during solid‐solution treatment and hot deformation behavior during extrusion process are analyzed. The role of minor (0.34 at%) Ca addition in the as‐cast alloy is related to the fine microstructure and abundant 18R‐LPSO phase. Furthermore, the precipitation of 14H‐LPSO phase is greatly induced by Ca addition in subsequent solid‐solution treatment. As for as‐extruded alloys, the dynamic precipitation behavior of W phase nanoparticles is found. The high‐density W phase nanoparticles suppress the dynamic recrystallization (DRX) behavior and inhibit the growth of dynamical recrystallized (DRXed) grains. The as‐extruded Ca‐modified alloy shows a superior mechanical property with yield strength (YS), ultimate tensile strength (UTS), and elongation of 400, 434 MPa, and 19.5%, respectively. The tiny microstructure, W phase nanoparticles, and kinky LPSO (both 18R and 14H type) phase are the reasons for the outstanding mechanical properties.

中文翻译：

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少量添加钙可增强Mg-Zn-Y-Mn合金的性能

本文中，钙（Ca）微合金化对Mg ₉₄ Zn _2.5 Y _2.5 Mn _1的组织和力学性能的影响合金被识别。分析了固溶处理过程中的长周期堆积有序（LPSO）相变机理和挤压过程中的热变形行为。铸态合金中少量（0.34 at％）Ca的添加与精细的组织和丰富的18R-LPSO相有关。此外，在随后的固溶处理中，添加Ca极大地诱导了14H-LPSO相的沉淀。对于挤压合金，发现了W相纳米颗粒的动态沉淀行为。高密度W相纳米颗粒可抑制动态重结晶（DRX）行为，并抑制动态重结晶（DRXed）晶粒的生长。挤压后的Ca改性合金具有优异的机械性能，屈服强度（YS），极限抗拉强度（UTS）和延伸率均为400，分别为434 MPa和19.5％。微小的微观结构，W相纳米颗粒和弯曲的LPSO相（18R和14H型）都是出色的机械性能的原因。