Deformation behavior of as-cast and as-extruded Mg97Zn1Y2 alloys during compression, as tracked by in situ neutron diffraction
Deformation behavior of as-cast and as-extruded Mg97Zn1Y2 alloys during compression, as tracked by in situ neutron diffraction
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DOI：
10.1016/j.ijplas.2018.08.001
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发表时间：
2018-12
影响因子：
9.8
通讯作者：
W. Gong;K. Aizawa;S. Harjo;Ruixiao Zheng;T. Kawasaki;J. Abe;T. Kamiyama;N. Tsuji
中科院分区：
文献类型：
--
作者：
W. Gong;K. Aizawa;S. Harjo;Ruixiao Zheng;T. Kawasaki;J. Abe;T. Kamiyama;N. Tsuji
热挤压是一种有效的镁合金强化工艺。研究了具有长周期堆垛有序（LPSO）相和α-Mg相双重组织的Mg 97 Zn 1 Y2合金的热挤压强化机制。利用原位中子衍射技术研究了Mg 97 Zn 1 Y2合金在铸态和挤压态下的单轴压缩变形行为。结果表明，热挤压可显著提高Mg 97 Zn 1 Y2合金的屈服强度。在铸态合金中，LPSO相通过基底滑移在−50 MPa的相当低的应力下屈服。然而，在α-Mg基体屈服后，LPSO相保持弹性行为并共享额外的晶格应力，直到挤压态合金在−289 MPa下发生扭结变形。铸态合金中LPSO相与周围共格的α-Mg基体的基底滑移结合是LPSO相屈服应力相对较低的原因。相应力分配的定量评价证实，LPSO相是显着增强的热挤压和扭结变形的LPSO相起着重要的作用，在保持塑性。
Hot extrusion is an effective process for strengthening magnesium alloys. In this study, we investigated the hot extrusion strengthening mechanism in an Mg97Zn1Y2alloy with a duplex microstructure consisting of a long period stacking ordered (LPSO) phase and an α-Mg phase. The deformation behavior of Mg97Zn1Y2alloys in the as-cast and as-extruded states was examined byin situneutron diffraction during uniaxial compression tests. The results show that the yield strength of Mg97Zn1Y2alloy was substantially enhanced by hot extrusion. The LPSO phase yielded at a rather low stress of −50 MPa in the as-cast alloy via basal slip. However, the LPSO phase persisted elastic behavior and shared additional lattice stress after the yielding of the α-Mg matrix until the onset of kink deformation at −289 MPa in the as-extruded alloy. The conjunction of basal slip in LPSO phase and the surrounding coherent α-Mg matrix is believed to be the reason for the relative low yield stress of the LPSO phase in the as-cast alloy. The quantitative evaluation of phase stress partition confirmed that the LPSO phase was significantly enhanced by hot extrusion and kink deformation of the LPSO phase plays an important role in preserving ductility.