Grain boundary plasticity in nanocrystalline alloys: Transition to glassy behavior?

纳米晶合金中的晶界塑性：向玻璃行为的转变？

• 批准号: 250679794
• 负责人: Professor Dr. Rainer Birringer
• 金额: --
• 依托单位: Lehrstuhl für Technische Physik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/250679794?language=en
• 关键词: Grain; boundary; plasticity; nanocrystalline; alloys

The goal of this project is to unravel the synergy and hierarchy of coexisting deformation modes in nanocrystalline (nc) PdAu-alloys at the low end of the nanoscale (< 10 nm). We put special emphasis on identifying and quantifying the evolution of shares of different elastic and plastic strain carrying deformation mechanisms. In the spirit of set theory, we have been able to identify that grain boundary mediated deformation mechanisms contribute in a dominant manner to overall strain in nc PdAu-alloys. We gathered ample evidence that shear tranformations (ST), the intrinsic flow event in disordered media, should be the active and dominant deformation mode in grain boundaries. In fact, we find that ST dominate the macroscopic deformation behavior. Based on a study of the stress dependence of the barrier height scaling in nc Pd90Au10, we could deduce a scaling relation for the stress strain-rate reponse of the material and conjecture that this viscoplastic material law should have universal character. The main trust of this proposal relies upon corroborating this conjecture. Since the observed stress dependence of barrier height scaling is a signature of quiet a variety of disorderd media, it seems straightforward to also look into nanglasses and figure out whether or not the universal viscoplastic material response prevails.

该项目的目的是揭示纳米晶（NC）PDAU-Alloys在纳米级低端（<10 nm）中共存变形模式的协同和层次结构。我们特别着重于识别和量化不同弹性和塑性应变变形机制的份额的演变。本着集合理论的精神，我们能够确定晶界介导的变形机制以主要方式促进NC PDAU合金中的整体应变。我们收集了充分的证据表明，剪​​切变形（ST）是无序介质中的固有流动事件，应是晶界的主动变形模式。实际上，我们发现ST主导了宏观变形行为。基于对NC PD90AU10屏障高度缩放的应力依赖性的研究，我们可以推断出材料和猜想的应力应变率响应的缩放关系，即这种粘塑料材料定律应该具有普遍特征。该提案的主要信任依赖于证实这一猜想。由于观察到的屏障高度缩放的应力依赖性是安静的各种混乱介质的标志，因此也很容易研究Nanglasses并弄清楚通用粘塑料材料响应是否占了上风。

项目成果

Structural relaxation of nanocrystalline PdAu alloy: Probing the spectrum of potential barriers

• DOI: 10.1063/1.5121520
• 发表时间: 2019-11
• 期刊: Journal of Applied Physics
• 影响因子: 3.2
• 作者: M. Deckarm;C. Braun;R. Birringer

Magnetic small-angle neutron scattering on bulk metallic glasses: a feasibility study for imaging displacement fields

• DOI: 10.1103/physrevmaterials.1.074403
• 发表时间: 2017-12
• 期刊: Physical Review Materials
• 影响因子: 3.4
• 作者: D. Mettus;M. Deckarm;A. Leibner;R. Birringer;M. Stolpe;Ralf Busch;D. Honecker;Joachim Kohlbrecher;P. Hautle;N. Niketic;Jesús Rodríguez Fernández;L. Barquín;A. Michels

Anatomizing deformation mechanisms in nanocrystalline Pd90Au10

• DOI: 10.1016/j.mechmat.2017.08.010
• 发表时间: 2017-11-01
• 期刊: MECHANICS OF MATERIALS
• 影响因子: 3.9
• 作者: Grewer, M.;Braun, C.;Birringer, R.
• 通讯作者: Birringer, R.

Elevated temperature, micro-compression transient plasticity tests on nanocrystalline Palladium-Gold: Probing activation parameters at the lower limit of crystallinity

纳米晶钯金的高温、微压缩瞬态塑性测试：探测结晶度下限的活化参数

• DOI: 10.1016/j.actamat.2017.02.045
• 发表时间: 2017
• 期刊: Acta Materialia
• 影响因子: 9.4
• 作者: J. Wehrs;M. J. Deckarm;J. M. Wheeler;X. Maeder;R. Birringer;S. Mischler;J. Michler
• 通讯作者: J. Michler

Structural relaxation of nanocrystalline PdAu alloy: Mapping pathways through the potential energy landscape

纳米晶 PdAu 合金的结构弛豫：绘制势能景观的路径

• DOI: 10.1063/1.5141525
• 发表时间: 2020
• 期刊: Journal of Applied Physics
• 影响因子: 3.2
• 作者: M. J. Deckarm;N. Boussard;C. Braun;R. Birringer
• 通讯作者: R. Birringer