Center for Advancing Materials Performance from the Nanoscale (CAMP-Nano) and Hysitron Applied Research Center in China (HARCC), State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, 710049, Xi'an, China.
Institute for Advanced Technology, Shandong University, 250061, Jinan, China.
Nat Commun. 2023 Jun 20;14(1):3670. doi: 10.1038/s41467-023-39296-6.
To alleviate the mechanical instability of major shear bands in metallic glasses at room temperature, topologically heterogeneous structures were introduced to encourage the multiplication of mild shear bands. Different from the former attention on topological structures, here we present a compositional design approach to build nanoscale chemical heterogeneity to enhance homogeneous plastic flow upon both compression and tension. The idea is realized in a Ti-Zr-Nb-Si-XX/Mg-Zn-Ca-YY hierarchically nanodomained amorphous alloy, where XX and YY denote other elements. The alloy shows ~2% elastic strain and undergoes highly homogeneous plastic flow of ~40% strain (with strain hardening) in compression, surpassing those of mono- and hetero-structured metallic glasses. Furthermore, dynamic atomic intermixing occurs between the nanodomains during plastic flow, preventing possible interface failure. Our design of chemically distinct nanodomains and the dynamic atomic intermixing at the interface opens up an avenue for the development of amorphous materials with ultrahigh strength and large plasticity.
为缓解室温下金属玻璃中主要剪切带的力学不稳定性，引入了拓扑异质结构以促使温和剪切带的增殖。与之前关注拓扑结构不同，我们提出了一种成分设计方法，以构建纳米尺度的化学非均匀性，从而在压缩和拉伸时增强均匀的塑性流动。该想法在 Ti-Zr-Nb-Si-XX/Mg-Zn-Ca-YY 分级纳米域非晶合金中得以实现，其中 XX 和 YY 表示其他元素。该合金在压缩时表现出2%的弹性应变，并经历高达40%应变的高度均匀的塑性流动（具有应变硬化），超过了单相和多相结构的金属玻璃。此外，在塑性流动过程中纳米域之间会发生动态原子混合，从而防止可能的界面失效。我们对化学上不同的纳米域的设计以及界面处的动态原子混合为开发具有超高强度和大塑性的非晶材料开辟了一条途径。
