In-situ synchrotron diffraction study on compressive deformation behavior of Mg92Y5Ni3 alloy mostly composed of LPSO
In-situ synchrotron diffraction study on compressive deformation behavior of Mg92Y5Ni3 alloy mostly composed of LPSO
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DOI：
10.1016/j.msea.2022.143292
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发表时间：
2022-05
期刊：
影响因子：
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通讯作者：
S.Z. Wu;Y. Chi;W. Xie;G. Garcés;X.H. Zhou;H. Brokmeier;S. Qin;X. Qiao;M. Y. Zheng
中科院分区：
文献类型：
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作者：
S.Z. Wu;Y. Chi;W. Xie;G. Garcés;X.H. Zhou;H. Brokmeier;S. Qin;X. Qiao;M. Y. Zheng
采用原位同步辐射技术，结合对不同应力下压缩变形轨迹的分析，研究了以长周期堆积有序相(LPSO)为主的铸态和挤压态镁92Y5Ni3(at.%)合金的压缩变形行为。铸态合金具有随机织构，而挤压态合金具有典型的基面织构，其基面平行于挤压(压缩)方向。在宏观屈服之前，一些取向较软的颗粒优先塑性变形，导致微观屈服。铸态和挤压态合金的微屈服行为均受基面滑移控制，挤压态合金的微屈服强度高于铸态合金。铸态和挤压态合金在宏观屈服点附近的激活变形方式均为柱状滑移，挤压后合金的抗压屈服强度由217 Mpa提高到Mpa，挤压态合金以硬质取向晶为主。柱面滑移后激活的扭结可在挤压态合金中引入大量位错，使合金的应变硬化率高达3000兆帕，极限抗压强度高达∼800兆帕，塑性应变在10%以上。
The compressive deformation behavior of the as-cast and as-extruded Mg92Y5Ni3(at.%) alloy mostly composed of long period stacking ordered (LPSO) phase was studied byin-situsynchrotron radiation combined with the analysis of deformation traces after compression at different applied stress. The as-cast alloy has random texture, while the as-extruded alloy has a typical basal texture with basal plane parallel to extrusion (compression) direction. Prior to macro-yielding, some softly oriented grains are preferentially plastically deformed, leading to micro-yielding. The micro-yielding behavior of both as-cast and as-extruded alloys is controlled by basal slip, the as-extruded alloy has higher micro-yielding strength than the as-cast alloy. The activated deformation mode near the macro-yielding point is prismatic slip in both as-cast and as-extruded alloys, and as the hard oriented grains dominate in the as-extruded alloy, the compressive yield strength of the alloy is increased from 217 MPa to 535 MPa after extrusion. The kinking activated following the prismatic slip can introduce a large number of dislocations in the as-extruded alloy, resulting in high strain-hardening rate of 3000 MPa, high ultimate compressive strength of ∼800 MPa and plastic strains above 10%.