单晶Pt中位错与非共格孪晶界反应的原位原子尺度观察

单晶Pt中位错与非共格孪晶界反应的原位原子尺度观察

郭谊忠，李  帅，王占鑫，李雪峤，王立华^*，韩晓东^*

(北京工业大学固体微结构与性能研究所，北京市重点实验室，北京 100124)

摘  要 非共格孪晶界(incoherent twin boundary, ITB)是金属中一种重要的晶界结构，其原子层次结构对金属的力学性能有显著影响。之前虽有一些关于ITB的结构演化及动态行为研究报道，但ITB与全位错相互反应导致ITB结构变化的原位研究还很少见，相关的原子层次机制仍然不清楚。本文以具有高密度生长孪晶的Pt薄膜为研究对象，利用高角环形暗场像揭示了Pt薄膜中ITB的原子结构。在原子层次原位观察到了全位错向ITB运动靠近，然后被ITB吸收的过程。原子尺度的位移分布测量表明全位错向ITB靠近的过程中就会引起ITB结构的变化。分子动力学模拟以及能量计算结果揭示出全位错容易被ITB吸引，然后形成了新的ITB结构而降低系统能量，这一结果很好地解释了这种新ITB结构在生长的薄膜中经常被观察到的原因。

关键词   Pt薄膜；全位错；非共格孪晶界；原子尺度；高角环形暗场像；原位

中图分类号：076；0482；TB34；TG115. 21⁺ 5. 3 

文献标识码：Adoi:10.3969/j.issn.1000-6281.2022.05.001

In situatomic-scale observation of dislocation reaction with incoherent twin boundary in Pt thin films

GUO Yi-zhong，LI Shuai，WANG Zhan-xin，LI Xue-qiao，WANG Li-hua*，HAN Xiao-dong*

(Beijing Key Lab of Microstructure and Property of Advanced Material, Beijing University of Technology, Beijing 100124, China)

Abstract   Incoherent twin boundary (ITB) is an important type of grain boundaries in metals, and its atomic-scale structures can significantly affect the mechanical properties of metals. Although there are some reports on the microstructural dynamic evolution of ITB, the in-situ atomic-scale study on the structural evolution of ITB induced by the interaction of full dislocation with ITB is still lacking, and the relevant atomistic mechanism is still unclear. In this paper, the atomic-scale structure of ITB in Pt thin films with high-density growth twins was investigated by using high-angle dark-field imaging technique. We found that full dislocations moved towards ITBs and adsorbed by these ITBs at atomic scale in real time. Atomic-scale displacement maps show that the motion of full dislocation towards ITBs can cause the change of ITB structures. Molecular dynamics simulation reveals that full dislocations are easily attracted by ITBs, and followed by the generation of new ITBs in order to lower the total energy of the system. Our results here provide a clear picture for understanding why new ITB structures in thin films can be frequently observed.

Keywords Pt thin film；full dislocation；incoherent twin boundary；atomic-scale；high-angle annular dark-field technique；in situ

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[1]     吕昭平，雷智锋，黄海龙，等. 高熵合金的变形行为及强韧化[J].  金属学报，2018, 54 (11): 1553-1566.

[2]     GOJNY F H, WICHMANN M, FIEDLER B, et al. Influence of nano-modification on the mechanical and electrical properties of conventional fibre-reinforced composites[J]. Composites Part A: Applied Science & Manufacturing, 2005, 36 (11): 1525-1535.

[3]     REISER A, KOCH L, DUNN K A, et al. Metals by micro‐scale additive manufacturing: comparison of microstructure and mechanical properties [J]. Advanced Functional Materials, 2020, 30 (28): 1910491.

[4]     LU K, LU L, SURESH S. Strengthening materials by engineering coherent internal boundaries at the nanoscale [J]. Science, 2009, 324 (5925): 349-352.

[5]     YIN F, CHENG G J, RONG X, et al. Ultrastrong nanocrystalline stainless steel and its Hall-Petch relationship in the nanoscale [J]. Scripta Materialia, 2018, 155: 26-31.

[6]     PARVEEN S, RANA S, FANGUEIRO R. A Review on nanomaterial dispersion, microstructure, and mechanical properties of carbon nanotube and nanofiber reinforced cementitious composites [J]. Journal of Nanomaterials, 2013, 2013 (7): 80.

[7]     MA Y, YANG M X, YUAN F P, et al. A review on heterogeneous nanostructures: a strategy for superior mechanical properties in metals [J]. Metals, 2019, 9 (5): 598.

[8]    卢磊, 卢柯. 纳米孪晶金属材料[J]. 金属学报, 2010, 46 (11): 1422-1427.

[9]     WANG L H, TENG J, KONG D L, et al. In situ atomistic deformation mechanisms of twin-structured nanocrystal Pt [J]. Scripta Materialia, 2018, 147: 103-107.

[10]   ZHANG Y, GUO J, MING W Q, et al. Atomic-scale study on incoherent twin boundary evolution in nanograined Cu [J]. Scripta Materialia, 2020, 186: 278-281.

[11]   WANG L H, GUAN P F, TENG J, et al. New twinning route in face-centered cubic nanocrystalline metals [J]. Nature Communications, 2017, 8 (1): 2142.

[12]   SUN S D, KONG D L, LI D H, et al. Atomistic mechanism of stress-induced combined slip and diffusion in Sub-5 nanometer sized Ag nanowires [J]. ACS Nano, 2019, 13 (8): 8708-8716.

[13]   WANG L H, DU K, YANG C P, et al. In situ atomic-scale observation of grain size and twin thickness effect limit in twin-structural nanocrystalline platinum [J]. Nature Communications, 2020, 11 (1): 1-9.

[14]   GUO Y Z, SUN T, FU L B, et al. In situ atomic-scale observation of dislocation behaviors in twin-structured Pt nanocrystals [J]. Science China Technological Sciences, 2021, 64 (3): 599-604.

[15]   张家宝，李志鹏，杨鲁岩，等. FCC金属中位错与孪晶界交互作用的原子机制[J]. 电子显微学报, 2020, 39 (6): 731-743.

[16]   CHEN Y, YU K Y, LIU Y, et al. Damage-tolerant nanotwinned metals with nanovoids under radiation environments [J]. Nature Communications, 2015, 6 (1): 1-8.

[17]   ZHU Y T, WU X L, LIAO X Z, et al. Dislocation–twin interactions in nanocrystalline fcc metals [J]. Acta Materialia, 2011, 59: 812-821.

[18]   YUE Y H, GAO Y F, HU W T, et al. Hierarchically structured diamond composite with exceptional toughness [J]. Nature, 582 (7812): 370-374.

[19]   ZHANG X, MISRA A, Wang H, et al. Nanoscale-twinning-induced strengthening in austenitic stainless steel thin films [J]. Applied Physics Letters, 2004, 84 (7): 1096-1098.

[20]   MISRA A, ZHANG X, HAMMON D, et al. Work hardening in rolled nanolayered metallic composites [J]. Acta Materialia, 2005, 53 (1): 221-226.

[21]   ZHANG X, WANG H, CHEN X H, et al. High-strength sputter-deposited Cu foils with preferred orientation of nanoscale growth twins [J]. Applied Physics Letters, 2006, 88 (17): 173116.

[22]   ANDEROGLU O, MISRA A, RONNING F, et al. Significant enhancement of the strength-to-resistivity ratio by nanotwins in epitaxial Cu films [J]. Journal of Applied Physics, 2009, 106 (2): 024313.

[23]   WANG Z J, LI Q J, LI Y, et al. Sliding of coherent twin boundaries [J]. Nature Communications, 2017, 8 (1): 1-7.

[24]   NIE J F, ZHU Y M, LIU J Z, et al. Periodic segregation of solute atoms in fully coherent twin boundaries [J]. Science, 2013, 340 (6135): 957-960.

[25]   ZHANG X, MISRA A. Superior thermal stability of coherent twin boundaries in nanotwinned metals [J]. Scripta Materialia, 2012, 66 (11): 860-865.

[26]   PRIESTER L. "Dislocation–interface" interaction — stress accommodation processes at interfaces [J]. Materials Science and Engineering: A, 2001, 309: 430-439.

[27]   HAN Y, LI H, FENG H, et al. Mechanism of dislocation evolution during plastic deformation of nitrogen-doped CoCrFeMnNi high-entropy alloy [J]. Materials Science and Engineering A, 2021, 814: 141235.

[28]   MOHAMADNEJAD S, BASTI A, ANSARI R. Analyses of dislocation effects on plastic deformation [J]. Multiscale Science and Engineering, 2020, 2 (2): 69-89.

[29]   KACHER J, EFTINK B P, CUI B, et al. Dislocation interactions with grain boundaries [J]. Current Opinion in Solid State and Materials Science, 2014, 18：227–243.

[30]   WANG Y B, WU B, SUI M L. Dynamical dislocation emission processes from twin boundaries [J]. Applied Physics Letters, 2008, 93 (4): 041906.

[31]   KOU Z D, FENG T, LAN S, et al. Observing dislocations transported by twin boundaries in Al thin film: unusual pathways for dislocation–twin boundary interactions [J]. Nano Letters, 2022, 22 (15): 6229-6234.

[32]   ERNST F, FINNIS M W, HOFMANN D, et al. Theoretical prediction and direct observation of the 9R structure in Ag [J]. Physical Review Letters, 1992, 69 (4): 620–623.

[33]   LIANG Y X, YANG X F, GONG M Y, et al. Slip transmission for dislocations across incoherent twin boundary [J]. Scripta Materialia, 2019, 166: 39-43.

[34]   WANG J, MISRA A, HIETH J P. Shear response of Σ3 {112} twin boundaries in face-centered-cubic metals [J]. Physical Review B, 2011, 83 (6): 064106.

[35]   ARZAGHI M, BEAUSIR B, TÓTH L S. Contribution of non-octahedral slip to texture evolution of fcc polycrystals in simple shear [J]. Acta Materialia, 2009, 57 (8): 2440-2453.

[36]   ZHU Y T, LIAO X Z, WU X L. Deformation twinning in nanocrystalline materials [J]. Progress in Materials Science, 2012, 57 (1): 1-62.

[37]   WU X L, LIAO X Z, Srinivasan S G, et al. New deformation twinning mechanism generates zero macroscopic strain in nanocrystalline metals [J]. Physical Review Letters, 2008, 100 (9): 095701.

[38]   ZHU Y T, NARAYAN J, HIRTH J P, et al. Formation of single and multiple deformation twins in nanocrystalline fcc metals [J]. Acta Materialia, 2009, 57 (13): 3763-3770.

[39]   WANG J, LI N, ANDEROGLU O, et al. Detwinning mechanisms for growth twins in face-centered cubic metals [J]. Acta Materialia, 2010, 58 (6): 2262-2270.

[40]   LIU L, WANG J, GONG S K, et al. High resolution transmission electron microscope observation of zero-strain deformation twinning mechanisms in Ag [J]. Physical Review Letters, 2011, 106 (17): 175504.

[41]   GUO Y Z, WANG Z X, ZHANG B, et al. Twin thickness and dislocation interactions affect the incoherent-twin boundary phase in face-centered cubic metals [J]. Cell Reports Physical Science, 2022, 3 (3): 100736.

[42]   WEI J, FENG B, ISHIKAWA R, et al. Direct imaging of atomistic grain boundary migration [J]. Nature Materials, 2021, 20 (7): 951-955.

[43]   HAN J, THOMAS S L, SROLOVITZ D J. Grain-boundary kinetics: a unified approach [J]. Progress in Materials Science, 2018, 98: 386–476.

[44]   FROLOV T, OLMSTED D L, ASTA M, et al. Structural phase transformations in metallic grain boundaries [J]. Nature Communications, 2013, 4: 1–7.

[45]   MEINERS T, FROLOV T, RUDD R E, et al. Observations of grain-boundary phase transformations in an elemental metal [J]. Nature, 2020, 579 (7799): 375-378.

[46]   BUFFORD D, LIU Y, WANG J, et al. In situ nanoindentation study on plasticity and work hardening in aluminum with incoherent twin boundaries [J]. Nature Communications, 2014, 5 (1): 1-9.