Laser powder bed fusion of an age-hardenable Mg-10Gd-0.2Zr alloy with excellent strength-ductility synergy
Laser powder bed fusion of an age-hardenable Mg-10Gd-0.2Zr alloy with excellent strength-ductility synergy
复制标题
具有优异强度-延展性协同作用的时效硬化 Mg-10Gd-0.2Zr 合金的激光粉末床熔合
DOI：
10.1016/j.jallcom.2022.164863
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发表时间：
2022
影响因子：
6.2
通讯作者：
Wenjiang Ding
中科院分区：
文献类型：
--
作者：
Qingchen Deng;Yu Zhang;Ziyi Liu;Zhiyu Chang;Ning Su;Yujuan Wu;Longlong Hao;Liming Peng;Wenjiang Ding
Mg-Gd合金一般需要先在相对较高的温度下进行固溶处理，然后在较低的温度下进行人工时效，以达到足够的强度，这需要几十个小时。本文报道了一种Mg- 10Gd-0.2Zr （wt%）合金，通过激光粉末床熔合获得了2791.3 MPa × %的极限抗拉强度和伸长率。优异的强度-延性协同作用归功于包含非均匀晶粒结构、粒内片层亚结构和纳米析出物的新型多尺度分层微观结构。在铸态Mg-10Gd-0.2Zr合金中，首次发现大量晶内β1相异常析出，呈块状；研究结果表明，LPBF过程中独特的热应变历史可以调节析出相的类型、面积数、密度、形貌和分布，从而控制力学性能。
Generally, Mg-Gd alloys need to be firstly solution treated at relatively high temperatures and then arti.ficially aged at low temperatures to achieve adequate strength, which costs dozens of hours. Herein a Mg- 10Gd-0.2Zr (wt%) alloy was reported to achieve excellent strength-ductility synergy with the product of ultimate tensile strength and elongation of 2791.3 MPa × % just by laser powder bed fusion (LPBF). The excellent strength-ductility synergy is attributed to the novel multi-scale hierarchical microstructure containing heterogeneous grain structure, intragranular lamellae substructure and nano-sized precipitates. Abnormal precipitation of a large number of intragranular β1 phases with blocky shape is first found in the as-built Mg-10Gd-0.2Zr alloy. The findings demonstrate that the unique heat and strain history during LPBF can be exploited to deliberately regulate the type, area number density, morphology and distribution of precipitates, thus controlling mechanical properties.