Improving microstructure and mechanical properties in Mg–6 mass% Zn alloys by combined addition of Ca and Ce
Improving microstructure and mechanical properties in Mg–6 mass% Zn alloys by combined addition of Ca and Ce
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DOI：
10.1016/j.msea.2016.01.034
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发表时间：
2016-02
期刊：
影响因子：
6.4
通讯作者：
Yuzhou Du;M. Zheng;X. Qiao;Debao Wang;W. Peng;K. Wu;B. Jiang
中科院分区：
文献类型：
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作者：
Yuzhou Du;M. Zheng;X. Qiao;Debao Wang;W. Peng;K. Wu;B. Jiang
在本研究中，Ca 单或 Ca-Ce 双微合金化 Mg-Zn 合金被铸造和挤压。 Ca和Ce的联合添加明显改善了Mg-6Zn合金挤压后的力学性能。微观结构分析表明，Ca 或 Ca-Ce 添加细化了动态再结晶 (DRXed) 微观结构，促进动态析出并改变了织构。挤压态 Mg-Zn-Ca-Ce 合金中的细小析出物钉扎位错运动并抑制动态再结晶，从而形成具有细晶 DRX 区域和拉长变形区域的双峰显微组织。添加Ca或Ca-Ce后，再结晶织构减弱，这主要归因于粒子刺激成核（PSN）和剪切带成核（SBN）。与单Ca微合金化相比，Ca-Ce双微合金化能更有效地提高Mg-6Zn合金的力学性能。挤压态 Mg-6Zn-0.7Ca-0.2Ce (mass%) 合金表现出良好的强度和延展性，屈服强度为 287 MPa，断裂伸长率为 16.9%，这与织构较弱的细 DRX 晶粒、高密度析出物以及变形区域具有较强的基底织构有关。
Ca single or Ca–Ce double microalloying Mg–Zn alloy was cast and extruded in the present study. The combined addition of Ca and Ce improved the mechanical properties of Mg–6Zn alloy after extrusion obviously. Microstructure analysis reveals that Ca or Ca–Ce addition refined the dynamic recrystallized (DRXed) microstructure, promoted dynamic precipitation and modified the texture. The fine precipitates in the as-extruded Mg–Zn–Ca–Ce alloy pinned dislocation movement and inhibited dynamic recrystallization, resulting in a bimodal microstructure with fine-grained DRXed region and elongated deformed region. The recrystallization texture was weakened with Ca or Ca–Ce addition, which was mainly attributed to the particle stimulated nucleation (PSN) and shear bands nucleation (SBN). Compared with single Ca microalloying, Ca–Ce double microalloying was more effective to improve the mechanical properties of Mg–6Zn alloy. The as-extruded Mg–6Zn–0.7Ca–0.2Ce (mass%) alloy exhibited a good combination of strength and ductility with the yield strength of 287 MPa and elongation-to-fracture of 16.9%, which was related to the fine DRXed grains with weaker texture, high density precipitates, and the deformed region with strong basal texture.