Revealing extraordinary tensile plasticity in layered Ti-Al metal composite
Revealing extraordinary tensile plasticity in layered Ti-Al metal composite
复制标题
揭示层状钛铝金属复合材料非凡的拉伸塑性
DOI：
10.1038/srep38461
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发表时间：
2016-12-05
影响因子：
4.6
通讯作者：
Xie, H. L.
中科院分区：
文献类型：
--
作者：
Huang, M.;Fan, G. H.;Xie, H. L.
采用热压和热轧工艺制备的层状Ti-Al金属复合材料(LMC)具有比这两种材料更高的延展性。本文结合数字图像相关(DIC)和X射线层析成像技术，揭示了应变离域和约束裂纹分布是产生异常拉伸延性的原因。应变离域是由于应变分配在Ti和Al层之间的转移而产生的，有效地缓解了LMC的应变局部化。此外，由于约束效应，LMC的扩展裂纹被限制在界面上。层状结构约束了裂纹的分布，显著缓解了应变局部化。同时，应变分配传递和约束裂纹分布抑制了钛的应变局部化，改变了钛的变形机制。我们的发现丰富了目前关于通过结构设计同时提高强度和延性的理解。
Layered Ti-Al metal composite (LMC) fabricated by hot-pressing and hot-rolling process displays higher ductility than that of both components. In this paper, a combination of digital image correlation (DIC) andX-ray tomography revealed that strain delocalization and constrained crack distribution are the origin of extraordinary tensile ductility. Strain delocalization was derived from the transfer of strain partitioning between Ti and Al layer, which relieved effectively the strain localization of LMC. Furthermore, the extensive cracks of LMC were restricted in the interface due to constraint effect. Layered architecture constrained the distribution of cracks and significantly relieved the strain localization. Meanwhile, the transfer of strain partitioning and constrained crack distribution were believed to inhibit the strain localization of Ti and change the deformation mechanisms of Ti. Our finding enriches current understanding about simultaneously improving the strength and ductility by structural design.