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相关论文: Multi-principal element grain boundaries: Stabiliz…

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Nanocrystalline alloys (nanoalloys) are prone to grain growth. It is known that grain boundary segregation and precipitation can stabilize nanoalloys, but the stabilization becomes less effective at high temperatures and adding grain growth…

材料科学 · 物理学 2022-12-22 Mingde Qin , Sashank Shivakumar , Jian Luo

Grain boundary structural transitions can lead to significant changes in the properties and performance of materials. In multi-principal element alloys, understanding these transitions becomes complex due to phenomena such as local chemical…

材料科学 · 物理学 2024-03-13 Ian Geiger , Diran Apelian , Xiaoqing Pan , Penghui Cao , Jian Luo , Timothy J. Rupert

Although nanocrystalline alloys regularly exhibit high strengths, their use in structural applications often face challenges due to sample size limitations, unstable microstructures, and the limited ability to plastically deform. The…

Local chemical ordering strongly influences the behavior of complex concentrated alloys, yet its characterization remains challenging due to the nanoscale dimensions and scattered spatial distribution of the ordered domains. Here, we study…

材料科学 · 物理学 2026-02-10 Ian Geiger , Yuan Tian , Ying Han , Yutong Bi , Xiaoqing Pan , Penghui Cao , Timothy J. Rupert

Elements with low thermal neutron absorption cross-sections are ideal for enhancing structural materials in nuclear systems. In this study, We systematically investigate the segregation and co-segregation behaviors of eleven elements at the…

材料科学 · 物理学 2025-11-26 Guanlin Lyu , Yuguo Sun , Panpan Gao , Ping Qian

Nanocrystalline materials are defined by their fine grain size, but details of the grain boundary character distribution should also be important. Grain boundary character distributions are reported for ball milled, sputter deposited, and…

材料科学 · 物理学 2016-01-27 David B. Bober , Amirhossein Khalajhedayati , Mukul Kumar , Timothy J. Rupert

Amorphous grain boundary complexions lack long-range crystalline order but are not featureless, as distinct gradients in structural short-range order have been reported through their thickness. In this work, we test the hypothesis that the…

材料科学 · 物理学 2023-09-19 Pulkit Garg , Timothy J. Rupert

Tailoring the nanoscale distribution of chemical species at grain boundaries is a powerful method to dramatically influence the properties of polycrystalline materials. However, classical approaches to the problem have tacitly assumed that…

材料科学 · 物理学 2024-11-11 Malik Wagih , Yannick Naunheim , Tianjiao Lei , Christopher A. Schuh

There are still debates regarding the mechanisms that lead to hot cracking in parts build by additive manufacturing (AM) of non-weldable Ni-based superalloys. This lack of in-depth understanding of the root causes of hot cracking is an…

Refractory multi-principal element alloys exhibiting promising mechanical properties such as excellent strength retention at elevated temperatures have been attracting increasing attention. Although their inherent chemical complexity is…

材料科学 · 物理学 2022-12-28 Ian Geiger , Jian Luo , Enrique J. Lavernia , Penghui Cao , Diran Apelian , Timothy J. Rupert

Segregation-induced structural transitions in metallic grain boundaries are studied with hybrid atomistic Monte Carlo/molecular dynamics simulations using Cu-Zr as a model system, with a specific emphasis on understanding the effect of…

材料科学 · 物理学 2016-04-27 Zhiliang Pan , Timothy J. Rupert

Interfacial segregation and chemical short-range ordering influence the behavior of grain boundaries in complex concentrated alloys. In this study, we use atomistic modeling of a NbMoTaW refractory complex concentrated alloy to provide…

Achieving a combination of high mechanical strength and high electrical conductivity in low-weight Al alloys requires a full understanding of the relationships between nanoscaled features and physical properties. Grain boundary…

材料科学 · 物理学 2020-08-27 Xavier Sauvage , Fabien Cuvilly , Alan Russell , Kaveh Edalati

Segregation to defects, in particular to grain boundaries (GBs), is an unavoidable phenomenon leading to changed material behavior over time. With the increase of available computational power, unbiased quantum-mechanical predictions of…

材料科学 · 物理学 2025-05-22 Dominik Gehringer , Lorenz Romaner , David Holec

It is believed that grain boundary segregation of light interstitials can serve as possible mechanism of thermal stability in commercially pure nanostructured titanium alloys. In this paper, using first-principles calculations, we show that…

材料科学 · 物理学 2015-06-15 D. A. Aksyonov , A. G. Lipnitskii , Yu. R. Kolobov

The grain boundary network of nanocrystalline Cu foils was modified by the systematic application of cyclic loadings and elevated temperatures having a range of magnitudes. Most broadly, the changes to the boundary network were directly…

材料科学 · 物理学 2019-02-20 David B. Bober , Thomas LaGrange , Mukul Kumar , Timothy J. Rupert

The intermetallic compound Zr3Al is severely deformed by the method of repeated cold rolling. By X-ray diffraction it is shown that this leads to amorphization. TEM investigations reveal that a homogeneously distributed debris of very small…

Grain boundary tracer diffusion of Ni, Fe and Cr was studied in a Ni-base 602CA coarse-grained alloy. A co-existence of several short-circuit contributions was distinguished at higher temperatures in Harrison's B-type regime (773-873 K),…

Annealing of crystalline multilayers composed of two miscible elements usually causes interfacial mixing of the constituent atoms, possibly leading to the formation of binary alloys at the interfaces. Magnetron sputtered c-Ni/a-Zr…

材料科学 · 物理学 2021-10-01 Debarati Bhattacharya , Vijay Karki , Surendra Singh , T. V. Chandrasekhar Rao

Atomistic simulations are used to study segregation-induced intergranular film formation in Cu-Zr and Cu-Nb alloys. While Cu-Zr forms structurally disordered or amorphous films, ordered films comprised of a second phase usually precipitate…

材料科学 · 物理学 2016-11-09 Zhiliang Pan , Timothy J. Rupert