Bake-hardenable Mg-Al-Zn-Mn-Ca sheet alloy processed by twin-roll casting
Bake-hardenable Mg-Al-Zn-Mn-Ca sheet alloy processed by twin-roll casting
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DOI：
10.1016/j.actamat.2018.07.057
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发表时间：
2018-10-01
期刊：
影响因子：
9.4
通讯作者：
Hono, K.
中科院分区：
文献类型：
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作者：
Bian, M. Z.;Sasaki, T. T.;Hono, K.
Mg-1.3Al-0.8Zn-0.7Mn-0.5Ca（wt.%）采用低成本双辊铸轧工艺生产的AZMX 1110镁合金板材具有良好的室温成形性能，其埃里克森指数（I.E.）在室温下在溶液处理条件下（T4）的值为7.8mm。在T4条件下，大的I.E.值与弱的基底结构有关。该合金在170 ℃下显示出快速的时效硬化响应，导致流动应力在20分钟内从198 MPa显著增加到238 MPa;这种烘烤硬化性（BH）以前从未在镁合金板材中探索过。通过透射电子显微镜和原子探针层析成像（TEM-APT）对烘烤硬化试样的显微结构进行了表征，结果表明Al、Zn和Ca原子在基体位错中偏聚，并通过位错运动和原子的共聚沿着强化。这是第一种仅由普遍存在的元素组成的BH Mg板材合金，对于应用于汽车车身具有高度吸引力。(C)2018 Acta Materialia Inc.爱思唯尔有限公司出版
Mg-1.3Al-0.8Zn-0.7Mn-0.5Ca (wt.%) (AZMX1110) alloy sheet produced by low-cost twin-roll casting process exhibits excellent room temperature formability with a large Index Erichsen (I.E.) value of 7.8 mm at room temperature in a solution treated condition (T4). The large I.E. value is associated with a weak basal texture in the T4-condition. This alloy shows rapid age-hardening response at 170 degrees C, resulting in a significant increase of the flow stress from 198 MPa to 238 MPa within 20 min; such bake hardenability (BH) has never been explored in magnesium sheet alloys before. The microstructure of the bake-hardened sample, characterized by a correlative transmission electron microscopy and atom probe tomography (TEM-APT), reveals that Al, Zn and Ca atoms are segregated to basal dislocations and contribute to the strengthening by pinning dislocation motions, along with the co-clustering of these atoms. This first BH Mg sheet alloy composed of only ubiquitous elements is highly attractive for application to automotive bodies. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd.