lrxin-材料物理与化学专业导师杜奎

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材料物理与化学专业导师杜奎

时间:2018-06-15 09:05 来源:中科院金属研究所研究生部 作者:研究生部 点击:

一、中文信息

1. 姓名:杜奎

2. 照片

 

3. 职务:博士生导师

4. 联系方式

办公电话:(024)83970725

手机:13904036887

Emailkuidu@imr.ac.cn

5. 教育和工作经历

2010.09—         中国科学院金属研究所 研究员

2006.03—2010.09 中国科学院金属研究所 副研究员

2003.02—2006.03 美国Case Western Reserve大学 Senior Research Associate

1999.08—2003.02 德国马普金属研究所 Research Fellow

1996.06—1999.06 中国科学院金属研究所 博士
1993.09—1996.06 中国科学院金属研究所 硕士

6. 主要研究方向

电子显微学;材料结构演化及其对性能的作用机理:

[1] 高温合金中位错结构演化的三维电子层析研究

[2] 亚稳beta型钛合金形变和相变机制的定量电子显微学研究

[3] 材料界面的亚埃尺度结构和材料性能

[4] 关键航空合金材料中动态应变时效的多尺度关联实验与机理研究

7. 近期发表论文

[1]     C.Y. Wang, K. Du*, K.P. Song, X.L. Ye, L. Qi, S.Y. He, D.M. Tang, N. Lu, H.J. Jin, F. Li, H.Q. Ye, “Size-dependent grain-boundary structure with improved conductive and mechanical stabilities in sub-10-nm gold crystals”, Physical Review Letters 120 (2018) 186102.

[2]     B.B. Jiang, A.D. Tu, H. Wang, H.C. Duan, S.Y. He, H.Q. Ye, K. Du*, “Direct observation of deformation twinning under stress gradient in body-centered cubic metals”, Acta Materialia 155 ( 2018) 56.

[3]     G. Yang, K. Du*, D.S. Xu, H. Xie, W.Q. Li, D.M. Liu, Y. Qi, H.Q. Ye, “High speed dynamic deformation of polysynthetic twinned titanium aluminide intermetallic compound”, Acta Materialia 152 ( 2018) 269.

[4]     D.Q. Qi, D. Wang, K. Du*, Y. Qi, L.H. Lou, J. Zhang, H.Q. Ye, “Creep deformation of a nickel-based single crystal superalloy under high stress at 1033 K”. Journal of Alloys and Compounds 735 (2018) 813.

[5]     T.T. Yao, K. Du*, H.L. Wang, Z.Y. Huang, C.H. Li, L.L. Li, Y.L. Hao, R. Yang, H.Q. Ye, “In situ scanning and transmission electron microscopy investigation on plastic deformation in a metastable β-titanium alloy”. Acta Materialia 133 ( 2017) 21.

[6]     T.T. Yao, K. Du*, H.L. Wang, L. Qi, S.Y. He, Y.L. Hao, R. Yang, H.Q. Ye, “Reversible twin boundary migration between α″ martensites in a Ti-Nb-Zr-Sn alloy”. Materials Science and Engineering A 688 (2017) 169.

[7]     K.P. Song, H. Zhang, K. Du*, D.Q. Qi, H.W. Chen, X.H. Wang, J.F. Nie, H.Q. Ye, “Atomic-scale microstructure of Hf2Al4C5 ceramic synthesized by spark plasma sintering”. Journal of the American Ceramic Society 100 (2017) 3208.

[8]     K.P. Song, K. Du*, H.Q. Ye, “Atomic structure and chemistry of a[100] dislocation cores in La2/3Sr1/3MnO3 films”. Micron 96 (2017) 72.

[9]     M. Song, S.Y. He, K. Du*, Z.Y. Huang, T.T. Yao, Y.L .Hao, S.J. Li, R. Yang, H.Q. Ye, “Transformation induced crack deflection in a metastable titanium alloy and implications on transformation toughening”, Acta Materialia 118 (2016) 120.

[10] D.Q. Qi, B.D. Fu, K. Du*, T.T. Yao, C.Y. Cui, J.X. Zhang, H.Q. Ye, “Temperature effects on the transition from Lomer-Cottrell locks to deformation twinning in a Ni-Co-based superalloy”, Scripta Materialia 125 (2016) 24.

[11] T.T. Yao, K. Du*, Y.L. Hao, S.J. Li, R. Yang, H.Q. Ye, “In-situ observation of deformation induced α" phase transformationin a β-titanium alloy”, Materials Letters 182 (2016) 281.

[12] M. Song, K. Du*, C.Y. Wang, S.P Wen, H. Huang, Z.R. Nie, H.Q. Ye, “Geometric and chemical composition effects on healing kinetics of voids in Mg-bearing Al alloys”, Metallurgical and Materials Transactions A 47 (2016) 2410.

[13]  W. Zhang, K. Du*, X.Q. Chen, L.Y. Sheng, H.Q. Ye, “Thermally stable coherent domain boundaries in complex-structured Cr2Nb intermetallics”, Philosophical Magazine 96 (2016) 58.

[14]  N. Lu, K. Du*, L. Lu, H.Q. Ye, “Transition of dislocation nucleation induced by local stress concentration in nanotwinned copper”, Nature Communications 6 (2015) 7648.

[15]  B.D. Fu, K. Du*, G.M. Han, C.Y. Cui, J.X. Zhang, “Deformation mechanisms in a Co-rich nickel based superalloy with different size of g' precipitates”, Materials Letters 152 (2015) 1572.

[16]  S.J. Wang, H. Wang, K. Du*, W. Zhang, M.L. Sui, S.X. Mao, “Deformation-induced structural transition in body-centred cubic molybdenum”, Nature Communications 5 (2014) 3433.

[17]  M. Song, K. Du*, Z.Y. Huang, H. Huang, Z.R. Nie, H.Q. Ye, “Deformation induced dissolution and growth of precipitates in an Al-Mg-Er alloy during high-cycle fatigues”, Acta Materialia 81 (2014) 409.

[18]  M. Song, K. Du*, S.P Wen, Z.R. Nie, H.Q. Ye, “In situ electron microscopy investigation of void healing in an Al-Mg-Er alloy at a low temperature”, Acta Materialia 69 (2014) 236.

[19]  N. Lu, K. Du*, L. Lu, H.Q. Ye, “Motion of 1/3 < 111 > dislocations on Sigma 3 {112} twin boundaries in nanotwinned copper”, Journal of Applied Physics 115 (2014) 024310.

[20]  Y.J. Xu, K. Du*, C.Y. Cui, H.Q. Ye, “Deformation twinning with zero macroscopic strain in a coarse-grained Ni-Co-based superalloy”, Scripta Materialia 77 (2014) 71.

[21]  Y.J. Xu, D.Q. Qi, K. Du*, C.Y. Cui, H.Q. Ye, “Stacking fault effects on dynamic strain aging in a Ni–Co-based superalloy”, Scripta Materialia, 87 (2014) 37.

[22]  J.W. Deng, K. Du*, B. Wu, M.L. Sui, “Nanometer to micrometer scaled inhomogeneous etching of bulk metallic glasses by ion sputtering”, Intermetallics 34 (2013) 75.

[23]  P.F. Yan, K. Du*, M.L. Sui, “Pyramidal dislocation induced strain relaxation in hexagonal structured InGaN/AlGaN/GaN multilayer”, Journal of Applied Physics 112 (2012) 083502.

[24]  J.W. Deng, K. Du*, M.L. Sui, “Medium range order of bulk metallic glasses determined by variable resolution fluctuation electron microscopy”, Micron 43 (2012) 827.

[25]  W. Zhang, R. Yu, K. Du*, Z.Y. Cheng, J. Zhu, H.Q. Ye, “Undulating slip in Laves phase and implications for deformation in brittle materials”, Physical Review Letters 106 (2011) 165505.

[26]  K. Du, F. Ernst, M. Pelsozy, J. Barthel, K. Tillmann, “Expansion of interatomic distances in platinum catalyst nanoparticles”, Acta Materialia 58 (2010) 836.

[27]  P.F. Yan, K. Du*, M.L. Sui, “Alpha- to gamma-Al2O3 martensitic transformation induced by pulsed laser irradiation”, Acta Materialia 58 (2010) 3867.

[28]  H. Zheng, A. Cao, C. Weinberger, J. Huang, K. Du, J. Wang, Y. Ma, Y. Xia, S. Mao, “Discrete plasticity in sub-10-nm-sized gold crystals”, Nature Communications 1 (2010) 144.

8. 学术活动

应邀在The 15th International Conference on Aluminum Alloys, The 8th Asean Microscopy Conference, The 2nd Sino-German Symposium on Advanced Electron Microscopy and Spectroscopy in Materials Science, The 9th Pacific Rim International Conference on Advanced Materials and Processing, The 6th World Materials Research Institute Forum, The 9th International Conference on Processing & Manufacturing of Advanced Materials等国际会议作邀请报告。

担任中国电镜学会理事

9. 重要科研成果

利用原位像差校正高分辨透射电镜、旋进电子衍射和定量应变分析,在尺寸小于10纳米的金纳米线中发现晶界结构存在显著的尺寸效应,该尺寸效应能有效地提高纳米线的力学及导电稳定性。这一研究揭示了超纳尺度金属材料中晶界结构的尺寸效应及行为。当纳米线直径大于10纳米时,取向差小于15°的晶界以位错型(DGB)形式存在,而取向差大于15°的晶界以结构单元型(SGB)存在,与块体材料相似。随着纳米线直径减小到10纳米以下,位错型与结构单元型晶界的临界取向差将大于15°并且随纳米线直径减小而增大。当纳米线直径为2纳米时,取向差为28.6°的大角晶界仍然以位错型的形式存在。定量应变分析发现,位错型晶界的周围存在明显的弹性应变场而结构单元型晶界周围没有,这使得位错型晶界的宽度明显宽于结构单元型,这个特征可以用来区别这两种晶界。原位像差校正电子显微学研究表明,尺寸效应形成的位错型晶界可以在外加应力作用下以位错墙滑移的方式进行晶界迁移,从而避免了传统大角晶界的晶界滑移,这有效地提高了纳米线的力学稳定性。原位透射电镜形变和电学测量结果表明,纳米线中位错型晶界导致的电阻增加远低于结构单元型晶界,这也提高了纳米线的导电稳定性。这一原子尺度的原位定量电子显微学研究揭示了超纳尺度小尺寸金属材料中晶界结构的尺寸效应,这一效应同时提高了材料的力学及电学稳定性,因而可能为微电子互连以及纳米器件的设计提供新的思路。


 

通过原位透射电镜观察和定量应变分析,发现孪晶片层厚度对不同类型位错活跃程度和位错形核处局部应力集中有明显影响,位错的主导形核机制在某一临界片层厚度(18 nm)会发生转变。这一研究揭示了块体纳米片层结构(比如孪晶)材料的微观变形机制与宏观力学性能之间的关系。由于位错形核和局部应力集中有关,所以纳米孪晶铜变形的主导位错形核机制主要取决于孪晶界台阶处和孪晶界/晶界交界处的局部应力集中程度。而局部应力集中程度受孪晶片层厚度的影响,在孪晶界台阶处的局部应力集中程度随着孪晶片层厚度的减小而减小,孪晶界/晶界交界处的应力集中程度随着孪晶片层厚度的减小而显著增加。两者应力集中程度相当时对应的临界孪晶片层厚度为18nm。这一原子尺度的定量应变分析的结果与宏观力学性能测试得到的临界孪晶片层厚度(15nm) 吻合,这为预测进而优化具有纳米片层结构的金属材料的力学性能提供了新途径。


 

体心立方(bcc)结构的金属和合金被人类广泛地应用在生产和生活当中。它们最主要的优点是在很宽的温度范围内和很大的应变状态下都表现出很高的强度,因此体心立方金属的变形行为一直以来都是物理学家和材料学家所关注的问题。但是体心立方金属的微观变形机制比较复杂,到目前为止人们对它的了解还很不透彻。我们通过原位透射电镜观察和定量应变分析,结合分子动力学计算,揭示了金属Mo在应力加载下由<001>取向的bcc晶粒通过面心立方结构(fcc)的中间相转变到<111>取向的bcc晶粒,实现了15.4%的拉伸应变。这一研究揭示了单质金属在高应力条件下的应力诱发相变变形机制。这说明了即使是bcc结构非常稳定的难熔金属Mo,当内部产生局部应力集中,而其它变形方式又受到抑制时,也会产生结构相变。在塑性变形时,应力诱发相变可以部分地释放材料内部的应力集中,从而协调材料的变形,阻止微裂纹的萌生和扩展,最终为改善体心立方金属的塑性做出贡献。此外,bcc1→fcc→bcc2相变所对应的54.7°晶格转动也为金属变形时的晶粒扭转提供了一条新途径。

 

金属间化合物虽然具有优异的高温力学性能,适合用作耐高温材料,但是它们在室温下的脆性严重地阻碍了其工业应用。这类材料要实现塑性变形,往往需要加热到很高的温度(脆-韧转变温度以上),位错才可能被激活。由于金属间化合物具有复杂和特殊的结构,位错在其中的运动不像在金属中那样简单,它们的滑移往往需要涉及几个甚至几十个原子的协调运动,而不仅仅是在某个固定的滑移面上简单的剪切过程。这样,位错滑移的区域也由一个滑移面扩展为一个滑移区域。这样复杂的过程需要通过高温的热激活降低原子间的键合,从而使得原子的协调运动成为可能。但是,目前还没有足够的实验证据显示这个复杂滑移过程的具体步骤,以解释热激活是如何促进位错运动的。我们利用球差校正电镜发现在Laves相金属间化合物中,位错通过反复地在上下两个不同的滑移面间来回跳跃,从而以波浪形状的路径向前滑移。这种位错滑移机制的产生归结于Laves相中不同原子层之间结合力的不同。这种特殊的变形机制将有利于解释金属间化合物在高温变形时存在脆-韧转变的特性。

 

 

 

二、英文信息

1. Name: Kui Du

2. Title: Professor

3. Contact Information

Tel: 024-83970725

Email: kuidu@imr.ac.cn

4. Education and Work Experience

2006-Present: Scientist, Institute of Metal Research, Chinese Academy of Sciences

2003-2006: Senior Research Associate, Case Western Reserve University, Cleveland, USA

1999-2003: Research Fellow, Max-Planck-Institute for Metal Research, Stuttgart, Germany

1999. Ph.D. Institute of Metal Research, Chinese Academy of Sciences

1996. M.Sc. Institute of Metal Research, Chinese Academy of Sciences

5. Research Interests

Transmission electron microscopy; Microstructure and microanalysis of materials

6. Recent Publication

[1]     C.Y. Wang, K. Du*, K.P. Song, X.L. Ye, L. Qi, S.Y. He, D.M. Tang, N. Lu, H.J. Jin, F. Li, H.Q. Ye, “Size-dependent grain-boundary structure with improved conductive and mechanical stabilities in sub-10-nm gold crystals”, Physical Review Letters 120 (2018) 186102.

[2]     B.B. Jiang, A.D. Tu, H. Wang, H.C. Duan, S.Y. He, H.Q. Ye, K. Du*, “Direct observation of deformation twinning under stress gradient in body-centered cubic metals”, Acta Materialia 155 ( 2018) 56.

[3]     G. Yang, K. Du*, D.S. Xu, H. Xie, W.Q. Li, D.M. Liu, Y. Qi, H.Q. Ye, “High speed dynamic deformation of polysynthetic twinned titanium aluminide intermetallic compound”, Acta Materialia 152 ( 2018) 269.

[4]     D.Q. Qi, D. Wang, K. Du*, Y. Qi, L.H. Lou, J. Zhang, H.Q. Ye, “Creep deformation of a nickel-based single crystal superalloy under high stress at 1033 K”. Journal of Alloys and Compounds 735 (2018) 813.

[5]     T.T. Yao, K. Du*, H.L. Wang, Z.Y. Huang, C.H. Li, L.L. Li, Y.L. Hao, R. Yang, H.Q. Ye, “In situ scanning and transmission electron microscopy investigation on plastic deformation in a metastable β-titanium alloy”. Acta Materialia 133 ( 2017) 21.

[6]     T.T. Yao, K. Du*, H.L. Wang, L. Qi, S.Y. He, Y.L. Hao, R. Yang, H.Q. Ye, “Reversible twin boundary migration between α″ martensites in a Ti-Nb-Zr-Sn alloy”. Materials Science and Engineering A 688 (2017) 169.

[7]     K.P. Song, H. Zhang, K. Du*, D.Q. Qi, H.W. Chen, X.H. Wang, J.F. Nie, H.Q. Ye, “Atomic-scale microstructure of Hf2Al4C5 ceramic synthesized by spark plasma sintering”. Journal of the American Ceramic Society 100 (2017) 3208.

[8]     K.P. Song, K. Du*, H.Q. Ye, “Atomic structure and chemistry of a[100] dislocation cores in La2/3Sr1/3MnO3 films”. Micron 96 (2017) 72.

[9]     M. Song, S.Y. He, K. Du*, Z.Y. Huang, T.T. Yao, Y.L .Hao, S.J. Li, R. Yang, H.Q. Ye, “Transformation induced crack deflection in a metastable titanium alloy and implications on transformation toughening”, Acta Materialia 118 (2016) 120.

[10] D.Q. Qi, B.D. Fu, K. Du*, T.T. Yao, C.Y. Cui, J.X. Zhang, H.Q. Ye, “Temperature effects on the transition from Lomer-Cottrell locks to deformation twinning in a Ni-Co-based superalloy”, Scripta Materialia 125 (2016) 24.

[11] T.T. Yao, K. Du*, Y.L. Hao, S.J. Li, R. Yang, H.Q. Ye, “In-situ observation of deformation induced α" phase transformationin a β-titanium alloy”, Materials Letters 182 (2016) 281.

[12] M. Song, K. Du*, C.Y. Wang, S.P Wen, H. Huang, Z.R. Nie, H.Q. Ye, “Geometric and chemical composition effects on healing kinetics of voids in Mg-bearing Al alloys”, Metallurgical and Materials Transactions A 47 (2016) 2410.

[13]  W. Zhang, K. Du*, X.Q. Chen, L.Y. Sheng, H.Q. Ye, “Thermally stable coherent domain boundaries in complex-structured Cr2Nb intermetallics”, Philosophical Magazine 96 (2016) 58.

[14]  N. Lu, K. Du*, L. Lu, H.Q. Ye, “Transition of dislocation nucleation induced by local stress concentration in nanotwinned copper”, Nature Communications 6 (2015) 7648.

[15]  B.D. Fu, K. Du*, G.M. Han, C.Y. Cui, J.X. Zhang, “Deformation mechanisms in a Co-rich nickel based superalloy with different size of g' precipitates”, Materials Letters 152 (2015) 1572.

[16]  S.J. Wang, H. Wang, K. Du*, W. Zhang, M.L. Sui, S.X. Mao, “Deformation-induced structural transition in body-centred cubic molybdenum”, Nature Communications 5 (2014) 3433.

[17]  M. Song, K. Du*, Z.Y. Huang, H. Huang, Z.R. Nie, H.Q. Ye, “Deformation induced dissolution and growth of precipitates in an Al-Mg-Er alloy during high-cycle fatigues”, Acta Materialia 81 (2014) 409.

[18]  M. Song, K. Du*, S.P Wen, Z.R. Nie, H.Q. Ye, “In situ electron microscopy investigation of void healing in an Al-Mg-Er alloy at a low temperature”, Acta Materialia 69 (2014) 236.

[19]  N. Lu, K. Du*, L. Lu, H.Q. Ye, “Motion of 1/3 < 111 > dislocations on Sigma 3 {112} twin boundaries in nanotwinned copper”, Journal of Applied Physics 115 (2014) 024310.

[20]  Y.J. Xu, K. Du*, C.Y. Cui, H.Q. Ye, “Deformation twinning with zero macroscopic strain in a coarse-grained Ni-Co-based superalloy”, Scripta Materialia 77 (2014) 71.

[21]  Y.J. Xu, D.Q. Qi, K. Du*, C.Y. Cui, H.Q. Ye, “Stacking fault effects on dynamic strain aging in a Ni–Co-based superalloy”, Scripta Materialia, 87 (2014) 37.

[22]  J.W. Deng, K. Du*, B. Wu, M.L. Sui, “Nanometer to micrometer scaled inhomogeneous etching of bulk metallic glasses by ion sputtering”, Intermetallics 34 (2013) 75.

[23]  P.F. Yan, K. Du*, M.L. Sui, “Pyramidal dislocation induced strain relaxation in hexagonal structured InGaN/AlGaN/GaN multilayer”, Journal of Applied Physics 112 (2012) 083502.

[24]  J.W. Deng, K. Du*, M.L. Sui, “Medium range order of bulk metallic glasses determined by variable resolution fluctuation electron microscopy”, Micron 43 (2012) 827.

[25]  W. Zhang, R. Yu, K. Du*, Z.Y. Cheng, J. Zhu, H.Q. Ye, “Undulating slip in Laves phase and implications for deformation in brittle materials”, Physical Review Letters 106 (2011) 165505.

[26]  K. Du, F. Ernst, M. Pelsozy, J. Barthel, K. Tillmann, “Expansion of interatomic distances in platinum catalyst nanoparticles”, Acta Materialia 58 (2010) 836.

[27]  P.F. Yan, K. Du*, M.L. Sui, “Alpha- to gamma-Al2O3 martensitic transformation induced by pulsed laser irradiation”, Acta Materialia 58 (2010) 3867.

[28]  H. Zheng, A. Cao, C. Weinberger, J. Huang, K. Du, J. Wang, Y. Ma, Y. Xia, S. Mao, “Discrete plasticity in sub-10-nm-sized gold crystals”, Nature Communications 1 (2010) 144.

7. Service to the Professional Societies

Council member of Chinese Electron Microscopy Society

8. Service to the International Journals

Reviewer of Nature Communications, Acta Materialia, Scripta Materialia, Journal of the American Ceramic Society.

9. Recent Research Achievement

By combining the quantitative strain analysis method with in situ imaging, he has resolved the dynamic stress in materials with atomic scale. This reveals a direct relationship between the microscopic dislocation activities and macroscopic mechanical properties of nanotwinned metals. He resolves an undulating slip process of dislocations in a Laves phase intermetallic compound, which helps understand the brittle-to-ductile transition of intermetallic compounds. A structural transformation accompanied by shear deformation is resolved by in situ straining of bcc metals, which reveals a deformation mechanism for elemental metals under high-stress deformation conditions. High stacking fault density and low stacking fault energy are measured in a Ni-Co-based superalloy; this finding suggests that the dynamic strain aging effects are caused by Suzuki segregation. A modular software package has been developed for quantitative strain measurement directly from atomic resolution images.