纳米压痕过程的多尺度准连续介质法研究
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摘要
纳米材料由于其特殊的力学性能引起了人们的广泛关注,例如高的强度、硬度、耐磨性、延展性以及低温超塑性等。纳米材料之所以表现出这些特殊的性能与材料内部结构和变形机制密切相关。纳米压痕技术是一种相对简单有效地评估薄膜材料力学性能的方法,通过纳米压痕实验不仅可以获得材料的相关性能参量,而且能够反映材料弹塑性转变的机制,揭示微观组织结构与宏观力学性能的关系。然而,纳米压痕是一个复杂的接触问题,进行纳米压痕试验时受到诸多因素的影响,例如材料表面粗糙度,衬底效应,晶界效应,压头几何形状,晶格各项异性和压痕尺寸效应等,即便是在相同的设备和试验条件下纳米压痕试验过程的重复性也不能得到保证,因此需要采用多尺度方法对纳米压痕过程进行模拟。
     为了深入研究纳米压痕过程中材料的微观破坏过程和弹塑性转变的机制,本文采用多尺度准连续介质法(Quasicontinuum method, QC)对薄膜材料纳米压痕过程进行模拟,探讨材料初始表面缺陷、晶格各向异性、压头尺寸、层间界面以及界面结构对纳米压痕过程的影响,本文的主要研究内容如下:
     (1)初始表面缺陷对纳米压痕过程的影响。研究了初始缺陷对纳米压痕过程中位错形核与发射、Peierls应力以及位错发射临界载荷的影响。研究表明,在整个纳米压痕过程中出现了多次位错形核与发射现象,初始缺陷对第1和第3对位错的形核与发射影响较小,而对第2对位错的形核与发射具有明显地推迟作用,并伴随有裂纹扩展现象;由于初始缺陷引起薄膜材料内部严重的晶格畸变,导致系统应变能和位错运动Peierls应力增加;裂纹扩展前,发射第2对位错需要的临界载荷增加,裂纹失稳后,位错发射需要的临界载荷下降。多尺度模拟获得的纳米硬度和位错Peierls应力与实验结果吻合。
     (2)晶格各向异性和压头尺寸效应对纳米压痕过程的影响。研究了晶格各项异性和压头尺寸对纳米压痕过程中纳米硬度,压头接触应力分布,位错形核临界载荷以及系统应变能的影响。研究表明,不同晶面纳米压痕过程中呈现出完全不同的位错现象,纳米压痕获得的载荷-位移曲线呈现出的不连续性与这些不同的位错活动密切相关;沿有利于开动滑移系的晶体取向,由于在该晶体取向下具有较多的滑移方向,易激活滑移系产生滑移,因此获得的纳米硬度值,压头法向和切向接触应力,位错形核临界载荷以及系统应变能较小;沿不利于开动滑移系的晶体取向,由于在该晶体取向下无明显的滑移方向,难激活滑移系产生滑移,因此获得的纳米硬度值,压头法向和切向接触应力,位错形核临界载荷以及系统应变能较大;模拟结果与实验结果以及Rice-Thomson (R-T)位错模型计算结果吻合。
     (3)层间界面对纳米压痕过程的影响。从数值仿真和理论研究两方面揭示了Cu/Ag双层薄膜纳米压痕过程中界面对双层薄膜的强化或弱化效应的本质。研究表明,纳米压痕过程中层间界面不仅对Cu/Ag双层薄膜具有强化效应,而且还具有弱化效应。对于界面的强化效应,它主要是由滑动位错在传输过程中所受的阻力控制(例如,映像力,晶格阻力以及滑动位错与失配位错之间的相互排斥力);滑动位错在传输过程中所受的阻力越大,界面对Cu/Ag双层薄膜的强化效果越好;对于界面的弱化效应,它主要是由于界面上失配位错形核及运动引起的严重应力集中和局部失配应变所致。然而,在Cu/Ag双层薄膜纳米压痕过程中,与界面对双层薄膜的弱化效应相比,界面对双层薄膜的强化效应占主导地位,主要表现为界面的强化作用。模拟结果与实验结果以及位错理论模型预测一致。
     (4)界面结构对纳米压痕过程的影响。详细分析了不同界面结构对Cu-Ag双层薄膜纳米压痕过程中滑动位错形核与发射、纳米硬度以及系统应变能的影响。研究表明,界面对上层薄膜内滑动位错的形核与发射具有明显的推迟作用;Cu-Ag双层薄膜系统的力学性能主要取决于其上层薄膜的力学性能;界面结构对滑动位错形核与发射临界压深和临界载荷以及系统纳米硬度具有显著影响,界面对双层薄膜系统具有软化效应,呈现出反Hall-Petch关系;不同的界面结构引起双层薄膜系统中呈现复杂的位错活动状态,导致系统应变能呈现显著变化。尤其是滑动位错与界面发生相互作用时,系统应变能将出现一次大幅度的跳跃。
Nanostructural materials have been the subject of intensive research in recent years due to its unique mechanical properties, such as high strength, hardness, superior wear resistance, high tensile ductility and superplasticity at relatively low temperatures. Research has shown that these unique mechanical properties are closely related to internal structure of nanomaterials and deformation mechanism. Nanoindentation has become a standard technique for evaluating the mechanical properties of thin film. The load-displacement response obtained from nanoindentation test can be used to predict the material properities, understand the nature of the elastic-plastic deformation mechanism, and reveal the relationships between the microstructure and the macroscopic mechanical properties. However, nanoindentation is a complicated contact problem, which can be strongly influenced by surface roughness, substrate effects, grain boundaries effects, indenter geometry, crystalline anisotropy and indentation size effect. The repeatability and reproducibility of nanoindentation test result are poor, even if the experimental equipment and condition are the same. Therefore, it is very important to study the incipient plasticity during nanoindentation by multiscale atomic simulation.
     To further study the microscopic failure process and the elastic-plastic deformation mechanism of thin film, the quasicontinuum method (QC) is employed to elucidate the details of incipient plasticity during nanoindentation. The influences of initial defect, crystalline anisotropy, indenter size, interface between adjacent layers and interfacial structure on nanoindentation are discussed, respectively. The main contents of this paper are as follows:
     (1) Effects of initial defect on nanoindentation. The nanoindentation processes under influences of the initial defect are investigated about dislocation nucleation, dislocation emission, Peierls stress, and load necessary for dislocation emission. The results demonstrate that the load versus displacement response curves experience many times abrupt drops with the emission of dislocations beneath the indenter. The initial defect is found to be insignificant on nucleation and emission of the 1st and 3r dislocation dipoles, but has a distinct effect on the 2nd dislocation dipole. The nucleation and emission of the 2nd dislocation dipole is postponed obviously because of the effect of initial defect, and then crack propagation is accompanied. The strain energy of thin film and Peierls stress of dislocation dipole beneath the indenter are increase with deformation processes due to the severe lattice distortion in the thin film. Before the cleavage occurs, the load necessary for the 2nd dislocation dipole nucleation and emission increases in nanoindentation with initial defect, on the contrary, it decreases after the cleavage occurred. The nanohardness and Peierls stress in this simulation show a good agreement with relevant theoretical and experimental results.
     (2) Effects of crystalline anisotropy and indenter size on nanoindentation. The nanoindentation deformation processes under influences of crystalline anisotropy and indenter size are investigated about hardness, load distribution, critical load for first dislocation emission and strain energy under the indenter. It is shown that entirely different dislocation activities are presented under the effect of crystalline anisotropy during nanoindentation. The sharp load drops in the load-displacement curves are caused by the different dislocation activities. Both crystalline anisotropy and indenter size are found to have distinct effect on hardness, contact stress distribution, critical load for first dislocation emission and strain energy under the indenter. The above quantities are decreased at the indenter into Ag thin film along the crystal orientation with more favorable slip directions that easy trigger slip systems; whereas those will increase at the indenter into Ag thin film along the crystal orientation with less or without favorable slip directions that hard trigger slip systems. The results are shown to be in good agreement with experimental results and Rice-Thomson dislocation model solution.
     (3) Effects of interface between adjacent layers on nanoindentation. The nature of strengthening and weakening effects of interface on Cu/Ag bilayer film and the underlying deformation mechanisms during nanoindentation are revealed from both the numerical and theoretical aspects. The investigations show that there is not only a strengthening effect of interface on Cu/Ag bilayer film system, but also a weakening effect. Concerning the strengthening effect, it is governed primarily by the resistance to the glide dislocation transmission, such as Image force, Peierls-Nabarro force and the repulsive force between the glide dislocation and the misfit dislocation. The bigger resistance will lead to the stronger strengthening effect. With regard to the weakening effect, it is produced by the stress concentration and local misfit strain in the core region of the misfit dislocations due to the nucleation and propagation of misfit dislocations along the interface, which can impair significantly the binding strength between adjacent layers. However, compared with the weakening effect induced by the nucleation and motion of misfit dislocations, it must be emphasized that the strengthening effect of interface on Cu/Ag bilayer film system is predominant. The multiscale simulation results are in good agreement with the experimental results and dislocation theory model.
     (4) Effects of interfacial structure on nanoindentation. The influences of interfacial structure on nanoindentation of Cu-Ag bilayer film system are analyzed systematically about glide dislocation nucleation and emission, nanohardness and strain energy. The results show that the nucleation and emission of glide dislocations are postponed obviously because most of the indentation energy is absorbed by the interface between adjacent layers. The mechanical property of Cu-Ag bilayer film system strongly depends on the performance of upper thin film. The interfacial structure is found to have distinct effect on critical load and critical indentation depth for first glide dislocation emission and nanohardness of bilayer film system. Due to the softening effect of interface, a reverse Hall-Petch phenomenon is typically observed in Cu-Ag bilayer film system. The complicated dislocation configurations caused by different interfacial structure during nanoindentation can lead to a greatly change in strain energy. In particular, during the interaction between glide dislocations and interface, the strain energy-displacement curve will represents an abrupt jump.
引文
[1]Feynman R P. There is plenty of room at the bottom [J]. Engineering and Science,1960, 23(22):55-59.
    [2]白春礼.纳米科技及其发展前景[J].科学通报,2001,46(2):89-92.
    [3]杨鼎宜,孙伟.纳米材料的结构特征与特殊性能[J].材料导报,2003,17(10):7-10.
    [4]陈文.纳米电子技术:电子工业的技术革命[J].航空维修与工程,2006,4:31-33.
    [5]王辅忠,张慧春,史冬梅,陆路,孙静静,张军.纳米陶瓷研究进展[J].材料导报,2006,20(S2):19-22.
    [6]唐苏亚.纳米材料与技术在微机械领域中的应用[J].微特电机,2002,5:33-34.
    [7]陈东初,郑家.纳米技术在涂料中的应用研究进展[J].电镀与涂饰,2001,20(6):47-51.
    [8]崔大祥,高华建.生物纳米材料的进展与前景[J].中国科学院院刊,2003,1:20-24.
    [9]周佩珩,邓龙江.磁性纳米晶颗粒电磁特性研究进展[J].功能材料,2006,37(9):1366-1368.
    [10]赵玉芳,杨伯君,张茹.纳米技术在光通信中的应用[J].光通信技术,2007,2:55-56.
    [11]毛克祥,程海斌,官建国.纳米材料在航天领域的应用与发展[J].中国粉体技术,2006,6:39-43.
    [12]张中太,林元华,唐子龙,张俊英.纳米材料及其技术的应用前景[J].材料工程,2000,3:42-48.
    [13]卢柯,卢磊.金属纳米材料力学性能的研究进展[J].金属学报,2000,36(8):785-789.
    [14]Koch C C. Synthesis of nanostructured materials by mechanical milling: Problems and opportunities [J]. Nanostructured Materials,1997,9(1-8):13-22.
    [15]Ho CH,TaiYC.微电子机械系统和流体流动[J].力学进展,1998,28(2):250-272.
    [16]Mcfadden S X, Mishra R S, Valiev R Z, Zhilyaev A P, Mukherjee A K. Low-temperature superplasticity in nanostructured nickel and metal alloys[J]. Nature,1999,398:684-686.
    [17]Lu L, Sui M L, Lu K. Superplastic extensibility of nanocrystalline copper at room temperature [J]. Science,2000,287:1463-1466.
    [18]Valiev R. Nanomaterial advantage [J]. Nature,2002,419:887-889.
    [19]Wang Y, Chen M, Zhou F, Ma E. High tensile ductility in a nanostructured metal [J]. Nature,2002,419:912-915.
    [20]Valiev R. Nanostructuring of metals by severe plastic deformation for advanced properties [J]. Nature Materials,2004,3:511-516.
    [21]高栋,袁哲俊,姚英学,高鹏,朱波.纳米尺度下材料显微硬度测试原理的研究[J].航空工艺技术,1998,4:18-19.
    [22]朱瑛,姚英学,周亮.纳米压痕技术及其试验研究[J].工具技术,2004,38(8):13-16.
    [23]Tabor D. Indentation hardness:Fifty years on a personal view [J]. Philosophical Magazine A,1996,74(5):1207-1212.
    [24]张泰华,杨业敏.纳米硬度技术的发展和应用[J].力学进展,2002,32(3):349-364.
    [25]Pethicai J B, Hutchings R, Oliver W C. Hardness measurement at penetration depths as small as 20 nm [J]. Philosophical Magazine A,1983,48(4):593-606.
    [26]Oliver W C, Pharr G M. An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments [J]. Journal of Materials Research,1992,7(6):1564-1583.
    [27]Pharr G M. Measurement of mechanical properties by ultra-low load indentation [J]. Materials Science and Engineering A,1998,253(1-2):151-159.
    [28]谢村毅.纳米压痕技术在材料科学中的应用[J].物理,2001,30(7):432-435.
    [29]高鹏,陶中敏,袁哲俊,姚英学.纳米压痕技术及其应用[J].中国机械工程,1996,7(5):58-59.
    [30]万建松,岳珠峰.采用压痕实验获得材料性能的研究现状[J].实验力学,2002,17(2):131-139.
    [31]Weihs T P, Hong S, Bravman J C, Nix W D. Mechanical deflection of cantilever microbeams:A new technique for testing the mechanical properties of thin films [J]. Journal of Materials Research,1988,3(5):931-942.
    [32]Mayo M J, Nix W D. A Micro-indentation study of superplasticity in Pb, Sn, and Sn-38 wt% Pb [J]. Acta Metallurgica 1988,36(8):2183-2192.
    [33]Field J S, Swain MV. A simple predictive model for spherical indentation [J]. Journal of Materials Research,1993,8(2):297-306.
    [34]Field J S, Swain MV. Determining the mechanical properties of small volumes of material from submicron spherical indentations [J]. Journal of Materials Research,1995, 10(1):101-112.
    [35]Swain M V. Mechanical property characterization of small volumes of brittle materials with spherical tipped indenters [J]. Materials Science and Engineering A,1998,253(1-2): 160-166.
    [36]Li X, Bhushan B. Dynamic mechanical characterization of magnetic tapes using nanoindentation techniques [J]. IEEE Transactions Magnetics,2001,37(4):1616-1619.
    [37]Li X D, Bhushan B. A review of nanoindentation continuous stiffness measurement technique and its applications [J]. Materials Characterization,2002,48(1):11-36.
    [38]Poisl W H, Oliver W C, Fabes B D. The relation between indentation and uniaxial creep in amorphous selenium [J]. Journal of Materials Research,1995,10(8):2024-2032.
    [39]Yang F Q, Li J C M, Shih C W. Computer of impression creep using the hyperbolic sine stress law [J]. Materials Science and Engineering A,1995,201(1):50-57.
    [40]Lucas B N, Oliver W C. Indentation power-law creep of high-purity indium [J]. Metallurgical and Materials Transactions A,1999,30(3):601-610.
    [41]Li X, Diao D, Bhushan B. Fracture mechanisms of thin amorphous carbon films in nanoindentation [J]. Acta Materialia,1997,45(11):4453-4461.
    [42]Li X, Bhushan B. Measurement of fracture toughness of ultra-thin amorphous carbon films [J]. Thin Solid Films,1998,315(1-2):214-221.
    [43]Li X D, Bhushan B. Evaluation of fracture toughness of ultra-thin amorphous carbon coatings deposited by different deposition techniques [J]. Thin Solid Films,1999,355-356: 330-336.
    [44]高东宇,朱瑛.纳米硬度测量的计算机仿真研究进展[J].林业机械与木工设备,2006,34(6):14-16.
    [45]吴晓京,吴子景,蒋宾.纳米压痕试验在纳米材料研究中的应用[J].复旦学报(自然科学版),2008,47(1):1-7.
    [46]郭玉宝,杨儒,李敏,刘家祥,李友芬.纳米材料结构与性能的计算机模拟研究[J].材料导报,2003,17(6):12-14.
    [47]李敏,梁乃刚,张泰华,王林栋.纳米压痕过程的三维有限元数值试验研究[J].力学学报,2003,35(3):257-264.
    [48]Chen W M, Li M, Zhang T H, Cheng Y T, Cheng C M. Influence of indenter tip roundness on hardness behavior in nanoindentation [J]. Materials Science and Engineering A, 2007,445-446:323-327.
    [49]张天林,陈宇航,黄文浩,王翔.纳米压痕中针尖效应的分析[J].中国科学技术大学学报,2009,39(4):403-408.
    [50]Bouzakis K D, Michailidis N, Hadjiyiannis S, Skordaris G, Erkens G. The effect of specimen roughness and indenter tip geometry on the determination accuracy of thin hard coatings stress-strain laws by nanoindentation [J]. Materials Characterization,2003,49(2): 149-156.
    [51]Wang T H, Fang T H, Lin Y C. A numerical study of factors affecting the characterization of nanoindentation on silicon [J]. Materials Science and Engineering A,2007,447(1-2): 244-253.
    [52]Yoshino M, Aoki T, Chandrasekaran N, Shirakashi T, Komanduri R. Finite element simulation of plane strain plastic-elastic indentation on single-crystal silicon [J]. International Journal of Mechanical Sciences,2001,43(2):313-333.
    [53]Liu Y, Varghese S, Ma J, Yoshino M, Lu H, Komanduri R. Orientation effects in nanoindentation of single crystal copper [J]. International Journal of Plasticity,2008,24(11): 1990-2015.
    [54]Bolshakov A, Pharr G M. Influences of pileup on the measurement of mechanical properties by load and depth sensing indentation techniques [J]. Journal of Materials Research, 1998,13(4):1049-1058.
    [55]Taljat B, Pharr G M. Development of pile-up during spherical indentation of elastic-plastic solids [J]. International Journal of Solids and Structures,2004,41(14): 3891-3904.
    [56]Garrido Maneiro M A, Rodringuez J. Pile-up effect on nanoindentation tests with spherical-conical tips [J]. Scripta Materialia,2005,52(7):593-598.
    [57]Sun Y, Bell T, Zheng S. Finite element analysis of the critical ratio of coating thickness to indentation depth for coating property measurement by nanoindentation [J]. Thin Solid Films, 1995,258(1-2):198-204.
    [58]Tsui T Y, Pharr G M. Substrate effects on nanoindentation mechanical property measurement of soft films on hard substrates [J]. Journal of Materials Research,1999,14(1): 292-301.
    [59]Panich N, Sun Y. Effect of penetration depth on indentation response of soft coatings on hard substrates:A finite element analysis [J]. Surface and Coatings Technology,2004, 182(2-3):342-350.
    [60]Pelegri A A, Huang X Q. Nanoindentation on soft film/hard substrate and hard film/soft substrate material systems with finite element analysis [J]. Composites Science and Technology,2008,68(1):147-155.
    [61]Alder N J, Wainwright T E. Phase transition for a hard sphere system [J]. Journal of Chemical Physics,1957,27:1208-1209.
    [62]Gerberich W W, Venkataraman S K, Huang H, Harvey S E, Kohlstedt D L. The injection of plasticity by millinewton contacts [J]. Acta Metallurgica et Materialia,1995,43(4): 1569-1576.
    [63]Gerberich W W, Nelson J C, Lilleodden E T, Anderson P, Wyrobek J T. Indentation induced dislocation nucleation:The initial yield point [J]. Acta Materialia,1996,44(9): 3585-3598.
    [64]Kelchner C L, Plimpton S J, Hamilton J C. Dislocation nucleation and defect structure during surface indentation [J]. Physical Review B,1998,58:11085-11088.
    [65]Kiely J D, Houston J E. Nanomechanical properties of Au (111), (001), and (110) surfaces [J]. Physical Review B,1998,57:12588-12594.
    [66]Gouldstone A, Van Vliet K J, Suresh S. Nanoindentation: Simulation of defect nucleation in a crystal [J]. Nature,2001,411:656.
    [67]Li J, Van Vliet K J, Zhu T, Yip S, Suresh S. Atomistic mechanisms governing elastic limit and incipient plasticity in crystals [J]. Nature,2002,418:307-310.
    [68]Kiely J D, Hwang R Q, Houston J E, Effect of surface steps on the plastic threshold in nanoindentation [J]. Physical Review Letters,1998,81:4424-4427.
    [69]Zimmerman J A, Kelchner C L, Klein P A, Hamilton J C, Foiles S M. Surface step effects on nanoindentation [J]. Physical Review Letters,2001,87:165507.
    [70]Diao J, Gall K, Dunn M L. Yield strength asymmetry in metal nanowires [J]. Nano Letters,2004,4(10):1863-1867.
    [71]Liang H Y, Woo C H, Huang H C, Ngan A H W, Yu T X. Crystalline plasticity on copper (001),(110) and (111) surfaces during nanoindentation [J]. Computer Modeling in Engineering and Sciences,2004,6(1):105-114.
    [72]Tsuru T, Shibutani Y. Anisotropic effects in elastic and incipient plastic deformation under (001), (110), and (111) nanoindentation of Al and Cu [J]. Physical Review B,2007,75: 035415.
    [73]Tschopp M A, McDowell D L. Tension-compression asymmetry in homogeneous dislocation nucleation in single crystal copper [J]. Applied Physics Letters,2007,90:121916.
    [74]Liu X H, Gu J F, Shen Y, Chen C F. Anisotropy in homogeneous dislocation nucleation by nanoindentation of single crystal Cu [J]. Scripta Materialia,2008,58(7):564-567.
    [75]Rao S I, Hazzledine P M. Atomistic simulations of dislocation-interface interactions in the Cu-Ni multilayer system [J]. Philosophical Magazine A,2000,80(9):2011-2040.
    [76]Wang J, Hoagland R, Hirth J, Misra A. Atomistic modeling of the interaction of glide dislocations with "weak" interfaces [J]. Acta Materialia,2008,56(19):5685-5693.
    [77]Maekawa K, Itoh A. Friction and tool wear in nano-scale machining-a molecular dynamics approach [J]. Wear,1995,188(1-2):115-122.
    [78]Komanduri R, Chandrasekaran N, Raff L M. MD simulation of indentation and scratching of single crystal aluminum [J]. Wear,2000,240(1-2):113-143.
    [79]Komanduri R, Chandrasekaran N, Raff L M. MD simulation of exit failure in nanometric cutting [J]. Materials Science and Engineering A,2001,311(1-2):1-12.
    [80]Ye Y Y, Biswas R, Morris J R, Bastawros A, Chandra A. Molecular dynamics simulation of nanoscale machining of copper [J]. Nanotechnology,2003,14(3):390-396.
    [81]Yan Y D, Sun T, Dong S, Luo X C, Liang Y C. Molecular dynamics simulation of processing using AFM pin tool [J]. Applied Surface Science,2006,252(20):7523-7531.
    [82]Rentsch R. Atomistic analysis of discontinuous deformation during cutting processes [J]. Materials Science and Engineering A,2008,483-484:391-393.
    [83]Ho C M, Tai Y C.微电子机械系统和流体流动[J].力学进展,1988,28(2):250-272.
    [84]杨卫,马新玲,王宏涛,洪伟.纳米力学进展[J].力学进展,2002,32(2):161-174.
    [85]杨卫,王宏涛,马新玲,洪伟.纳米力学进展(续)[J].力学进展,2003,33(2):175-186.
    [86]胡壮麒,王鲁红,刘轶.电子和原子层次材料行为的计算机模拟[J].材料研究学报,1998,12(1):1-19.
    [87]冯端,金国钧.凝固态物理学中的基本概念[J].物理学进展,2000,20(1):1-21.
    [88]曹礼群.材料物性的多尺度关联与数值模拟[J].世界科技研究与发展,24(6):23-30.
    [89]柴立和.多尺度科学的研究进展[J].化学进展,2005,17(2):186-191.
    [90]刘更,刘天祥,张征,沈允文.宏观-微观多尺度数值计算方法研究进展[J].中国机械工程,2005,16(16):1493-1499.
    [91]郭雅芳,王崇愚.多尺度材料模型研究及应用[J].材料导报,2001,15(7):9-11.
    [92]Tadmor E B. The Quasicontinuum Method [D]. Brown University,1996.
    [93]Tadmor E B, Ortiz M, Phillips R. Quasicontinuum analysis of defects in solids [J]. Philosophical Magazine A,1996,73(6):1529-1563.
    [94]Shenoy V B, Miller R, Tadmor E B, Phillips R, Ortiz M. Quasicontinuum models of interfacial structure and deformation [J]. Physical Review Letters,1998,80:742-745.
    [95]Shenoy V B, Miller R, Tadmor EB, Rodney D, Phillips R, Ortiz M. An adaptive finite element approach to atomic-scale mechanics-the quasicontinuum method [J]. Journal of the Mechanics and Physics of Solids,1999,47(3):611-642.
    [96]Rudd R E, Broughton J Q. Concurrent coupling of length scales in solid state systems [J]. Physica Status Solidi b,2000,217(1):251-291.
    [97]Xiao S P, Belytschko T. A bridging domain method for coupling continua with molecular dynamics [J]. Computer Methods in Applied Mechanics and Engineering,2004,193(17-20): 1645-1669.
    [98]Wagner G J, Liu W K. Coupling of atomistic and continuum simulations using a bridging scale decomposition [J]. Journal of Computational Physics,2003,190(1):249-274.
    [99]Qian D, Wagner G J, Liu W K.A multiscale projection method for the analysis of carbon nanotubes [J]. Computer Methods in Applied Mechanics and Engineering,2004,193(17-20): 1603-1632.
    [100]Datta D K, Picu C, Shephard M S. Composite grid atomistic continuum method:an adaptive approach to bridge continuum with atomistic analysis [J]. International Journal of Multiscale Computational Engineering,2003,2:71-90
    [101]Kohlhoff S, Gumbsch P, Fischmeister H F. Crack propagation in b.c.c. crystals studied with a combined finite-element and atomistic model [J]. Philosophical Magazine A,1991, 64(4):851-878.
    [102]Shilkrot L E, Miller R E, Curtin W A. Coupled atomistic and discrete dislocation plasticity [J]. Physical Review Letters,2002,89:025501.
    [103]Shilkrot L E, Miller R E, Curtin W A. Multiscale plasticity modeling: coupled atomistic and discrete dislocation mechanics [J]. Journal of the Mechanics and Physics of Solids,2004, 52(4):755-787.
    [104]Luan B Q, Hyun S, Molinari J F, Bernstein N, Robbins M O. Multiscale modeling of two-dimensional contacts [J]. Physical Review E,2006,74:046710.
    [105]田文超,贾建授.MEMS粘附问题研究[J].仪器仪表学报,2003,24(4):582-584.
    [106]Nix W D, Gao H J. Indentation size effects in crystalline materials:a law for strain gradient plasticity [J]. Journal of the Mechanics and Physics of Solids,1998,46(3):411-425.
    [107]Tuck J R, Korsunsky A M, Bull S J, Davidson R I. On the application of the work-of-indentation approach to depth-sensing indentation experiments in coated systems [J]. Surface and Coatings Technology,2001,137(2-3):217-224.
    [108]Beegan D, Chowdhury S, Laugier M T. Work of indentation methods for determining copper film hardness [J]. Surface and Coatings Technology,2005,192(1):57-63.
    [109]Hainsworth S V, Chandler H W, Page T F. Analysis of nanoindentation load-displacement loading curves [J]. Journal of Materials Research,1987,11(8):1987-1995.
    [110]黎明,温诗铸.纳米压痕技术及其应用[J].中国机械工程,2002,13(16):1437-]439.
    [111]高栋,姚英学,袁哲俊.纳米级显微硬度试验研究[J].航空精密制造技术,2001,37(1):7-10.
    [112]Gong J H, Miao H Z, Peng Z J, Qi L H. Effect of peak load on the determination of hardness and Young's modulus of hot-pressed Si3N4 by nanoindentation [J]. Materials Science and Engineering A,2003,354(1-2):140-145.
    [113]王玉桂,乔利杰,高克玮,宿彦京,褚武扬,王中林.单晶SnO2纳米带裂纹形核的临界应力和断裂韧性[J].金属学报,2004,40(6):594-598.
    f114]于峰,史立秋,王涛.单晶硅的纳米硬度测试分析[J].金属热处理,2005,30(8):88-91.
    [115]周亮,姚英学.纳米压痕硬度计测方法的研究进展[J].计测技术,2006,26(6):6-9.
    [116]黎明,温诗涛.纳米压痕技术理论基础[J].机械工程学报,2003,39(3):142-145.
    [117]Tadmor E B, Phillips R, Ortiz M. Mixed atomistic and continuum models of deformation in solids [J]. Langmuir,1996,12 (19):4529-4534.
    [118]Phillips R. Multiscale modeling in the mechanics of materials [J]. Current Opinion in Solid State and Materials Science,1998,3(6):526-532.
    [119]Miller R E, Tadmor E B. The quasicontinuum method:Overview, applications and current direction [J]. Journal of Computer-Aided Materials Design,2002,9(3):203-239.
    [120]Shenoy V B. Multi-scale modeling strategies in materials science-the quasicontinuum method [J]. Bulletin of Materials Science,2003,26(1):53-62.
    [121]Park H, Liu W K. An introduction and tutorial on multiple-scale analysis in solids [J]. Computer Methods in Applied Mechanics and Engineering,2004,193(17-20):1733-1772.
    [122]张晓宇,黄再兴.连续介质理论在研究碳纳米管力学性能中的应用进展[J].机械强度,2005,27(3):324-330.
    [123]戴保东,程玉民.准连续体方法研究进展[J].力学季刊,2005,26(3):433-437.
    [124]倪玉山,王华滔.准连续介质方法及其应用[J].机械工程学报,2007,43(8):101-108.
    [125]Heino P, Hakkinen H, Kaski K. Molecular-dynamics study of mechanical properties of copper [J]. Europhysics Letters,1998,41(3):273-278.
    [126]Prudhomme S, Bauman P T, Oden J T. Error control for molecular statics problems [J]. International Journal for Multiscale Computational Engineering,2006,4(5-6):647-662.
    [127]Norskφv J K, Lang N D. Effective-medium theory of chemical binding: Application to chemisorptions [J]. Physical Review B,1980,21(6):2131-2136.
    [128]Daw M S, Baskes M I. Embedded-atom method:Derivation and application to impurities, surface, and other defects in metals [J]. Physical Review B,1984,29(12): 6443-6453.
    [129]Stillinger F H, Weber T A. Computer simulation of local order in condensed phases of silicon [J]. Physical Review B,1985,31(8):5262-3271.
    [130]Ericksen J L. The Cauchy and Born hypotheses for crystals [A]. In:Gurtin M. Phase Transformations and Material Instabilities in Solids. New York: Academic Press,1984: 117-133.
    [131]Knap J, Ortiz M. An analysis of the quasicontinuum method [J]. Journal of the Mechanics and Physics of Solids,2001,49 (9):1899-1923.
    [132]Miller R, Tadmor E B. A unified framework and performance benchmark of fourteen multiscale atomistic/continuum coupling methods [J]. Modelling and Simulation in Materials Science and Engineering,2009,17(5):053001.
    [133]Pandolfi A, Ortiz M. An efficient adaptive procedure for three-dimensional fragmentation simulations [J]. Engineering with Computers,2002,18(2):148-159.
    [134]Xu X P, Needleman A. Numerical simulations of fast crack growth in brittle solids [J]. Journal of the Mechanics and Physics of Solids,1994,42(9):1397-1434.
    [135]Tadmor E B, Miller R, Phillips R, Ortiz M. Nanoindentation and incipient plasticity [J]. Journal of Materials Research,1999,14(6):2233-2250.
    [136]Smith G S, Tadmor E B, Kaxiras E. Multiscale simulation of loading and electrical resistance in silicon nanoindentation [J]. Physical Review Letters,2000,84(6):1260-1263.
    [137]Smith G S, Tadmor E B, Bernstein N, Kaxiras E. Multiscale simulations of silicon nanoindentation [J]. Acta Materialia,2001,49 (19):4089-4101.
    [138]Knap J, Ortiz M. Effect of indenter-radius size on Au (001) nanoindentation [J]. Physical Review Letters,2003,90(22):226102.
    [139]Shan D B, Yuan L, Guo B. Multiscale simulation of surface step effects on nanoindentation [J]. Materials Science and Engineering A,2005,412:264-270.
    [140]曾凡林,孙毅.镍单晶薄膜纳米压痕的准连续介质模拟[J].固体力学学报,2006,27(4):341-345.
    [141]黎军顽,江五贵.基于准连续介质法预测薄膜材料纳米硬度和弹性模量[J].金属学报,2007,43(8):851-856.
    [142]江五贵,黎军顽,苏建君,汤井伦.纳米压痕试验中压头尺寸效应的准连续介质法分 析[J].固体力学学报,2007,28(4):375-379.
    [143]Jiang W G, Su J J, Feng X Q. Effect of surface roughness on nanoindentation test of thin films [J]. Engineering Fracture Mechanics,2008,75(17):4965-4972.
    [144]赵星,李久会,王绍青,张彩碚.纳米压痕实验中单晶Cu初始塑性变形的准连续介质模拟[J].金属学报,2008,44(12):1455-1460.
    [145]Jin J, Shevlin S A, Guo Z X. Multiscale simulation of onset plasticity during nanoindentation of Al (001) surface [J]. Acta Materialia,2008,56(16):4258-4368.
    [146]Wang H T, Qin Z D, Ni Y S, Zhuang W. Quasicontinuum simulation of indentation on FCC metals [J]. Transactions of Nonferrous Metals Society of China,2008,18(5):1164-1171.
    [147]王华滔,秦昭栋,倪玉山,张文.不同晶体取向下纳米压痕的多尺度模拟[J].物理学报,2009,58(2):1057-1063.
    [148]黎军顽,倪玉山,林逸汉,罗诚.Al薄膜纳米压痕过程的多尺度模拟[J].金属学报,2009,45(2):129-136.
    [149]Yu W S, Shen S P. Multiscale analysis of the effects of nanocavity on nanoindentation [J]. Computational Materials Science,2009,46(2):425-436.
    [150]Yu W S, Shen S P. Effects of small indenter size and its position on incipient yield loading during nanoindentation [J]. Materials Science and Engineering A,2009,526(1-2): 211-218.
    [151]Li J W, Ni Y S, Wang H S, Mei J F. Effects of crystalline anisotropy and indenter size on nanoindentation by multiscale simulation [J]. Nanoscale Research Letters,2010,5(2): 420-432.
    [152]Sansoz F, Dupont V. Atomic mechanism of shear localization during indentation of a nanostructured metal [J]. Materials Science and Engineering C,2007,27(5-8):1509-1513.
    [153]Dupont V, Sansoz F. Quasicontinuum study of incipient plasticity under nanoscale contact in nanocrystalline aluminum [J]. Acta Materialia,2008,56(20):6013-6026.
    [154]Sansoz F, Dupont V. Grain growth behavior at absolute zero during nanocrystalline metal indentation [J]. Applied Physics Letters,2006,89(11):111901.
    [155]Dupont V, Sansoz F. Grain boundary structure evolution in nanocrystalline Al by nanoindentation simulations [A]. In:Ma E, Schuh C A, Li Y, Miller M K. Amorphous and Nanocrystalline Metals for Structural Applications, Materials Research Society Proceedings, Volume 903E [C]. PA:Warrendale,2005:0903-Z06-05.
    [156]Sansoz F, Dupont V. Deformation of nanocrystalline metals under nanoscale contact [A]. In: Matthew Laudon.Technical Proceedings of the 2006 NSTI Nanotechnology Conference and Trade Show, Volume 1. Boston: Taylor and Francis,2006:50-53.
    [157]Iglesias R A, Leiva E P M. Two-grain nanoindentation using the quasicontinuum method:Two-dimensional model approach [J]. Acta Materialia,2006,54(10):2655-2664.
    [158]Chen P, Shen Y P. Nanocontact between BCC tungsten and FCC nickel using the quasicontinuum method [J]. International Journal of Solids and Structures,2008,45(24): 6001-6017.
    [159]Mei J F, Li J W, Ni Y S, Wang H T. Multiscale simulation of indentation, retraction and fracture processes of nanocontact [J]. Nanoscale Research Letters,2010, in press.
    [160]Shao Y F, Wang S Q. Quasicontinuum study on formation of fivefold deformation twin in nanocrystalline Aluminum [J]. Scripta Materialia,2010,62(6):419-422.
    [161]Miller R, Ortiz M, Phillips R, Shenoy V B, Tadmor E B. Quasicontinuum models of fracture and plasticity [J]. Engineering Fracture Mechanics,1998,61(3-4):427-444.
    [162]Miller R, Tadmor E B, Phillips R, Ortiz M. Quasicontinuum simulation of fracture at the atomic scale [J]. Modelling and Simulation in Materials Science and Engineering,1998, 6(5):607-638.
    [163]Shenoy V B, Miller R, Tadmor E B, Phillips R, Ortiz M. Quasicontinuum models of interfacial structure and deformation [J]. Physical Review Letters,1998,80(4):742-745.
    [164]Tadmor E B, Hai S. A Peierls criterion for the onset of deformation twinning at a crack tip [J]. Journal of the Mechanics and Physics of Solids,2003,51(5):765-793.
    [165]Hai S, Tadmor E B. Deformation twinning at aluminum crack tips [J]. Acta Materialia, 2003,51(1):117-131.
    [166]Tadmor E B, Bernstein N. A first-principles measure for the twinnability of FCC metals [J]. Journal of the Mechanics and Physics of Solids,2004,52(11):2507-2519.
    [167]Zhou T, Yang X H, Chen C Y. Quasicontinuum simulation of single crystal nano-plate with a mixed-mode crack [J]. International Journal of Solids and Structures,2009,46(9): 1975-1980.
    [168]Zhang Z N, Ge X R. A new quasi-continuum constitutive model for crack growth in an isotropic solid [J]. European Journal of Mechanics-A/Solids,2005,24(2):243-252.
    [169]Sansoz F, Molinari J F. Incidence of atom shuffling on the shear and decohesion behavior of a symmetric tilt grain boundary in copper [J]. Scripta Materialia,2004,50(10): 1283-1288.
    [170]Sansoz F, Molinari J F. Size and microstructure effects on the mechanical behavior of FCC bicrystals by quasicontinuum method [J]. Thin Solid Films,2005,515(6):3158-3163.
    [171]Sansoz F, Molinari J F. Mechanical behavior of ∑ tilt grain boundaries in nanoscale Cu and Al:A quasicontinuum study [J]. Acta Materialia,2005,53(7):1931-1944.
    [172]Marian J, Knap J, Ortiz M. Nanovoid deformation in aluminum under simple shear [J]. Acta Materialia,2005,53(10):2893-2900.
    [173]倪玉山,王华滔.晶体位错尺寸效应的多尺度分析[J].力学季刊,2005,26(3):366-369.
    [174]王华滔,倪玉山,秦昭栋.面心立方铝剪切变形的准连续介质模拟[J].固体力学学报,2009,30(3):217-225.
    [175]Rodney D, Phillips R. Structure and Strength of dislocation junctions:An atomic level analysis [J]. Physical Review Letters,1999,82(8):1074-1077.
    [176]Shin C S, Fivell M C, Rodney D, Phillips R, Shenoy V B, Dupuy L. Formation and strength of dislocation junctions in FCC metals:A study by dislocation dynamics and atomistic simulations [J]. Journal de Physique Ⅳ,2001,11(5):19-26.
    [177]Hardikar K, Shenoy V, Phillips R. Reconciliation of atomic-level and continuum notions concerning the interaction of dislocations and obstacles [J]. Journal of the Mechanics and Physics of Solids,2001,49(9):1951-1967.
    [178]Phillips R, Dittrich M, Schulten K. Quasicontinuum representations of atomic-scale mechanics: From proteins to dislocations [J]. Annual Review of Materials Research,2002,32: 219-233.
    [179]Lew A, Caspersen K, Carter E A, Ortiz M. Quantum mechanics based multiscale modeling of stress-induced phase transformations in iron [J]. Journal of the Mechanics and Physics of Solids,2006,54(6):1276-1303.
    [180]Truskinovsky L, Vainchtein A. Quasicontinuum models of dynamic phase transitions [J]. Continuum Mechanics and Thermodynamics,2006,18(1-2):1-21.
    [181]Dobson M, Elliott R S, Luskin M, Tadmor E B. A multilattice quasicontinuum for phase transforming materials:Cascading Cauchy Born kinematics [J]. Journal of Computer-Aided Materials Design,2007,14(1):219-237.
    [182]Arroyo M, Belytschko T. A finite deformation membrane based on inter-atomic potentials for the transverse mechanics of nanotubes [J]. Mechanics of Materials,2003, 35(3-6):193-215.
    [183]Park J Y, Cho Y S, Kim S Y, Jun S, Im S. A quasicontinuum method for deformations of carbon nanotubes [J]. Computer Modeling in Engineering and Science,2006,11(2):61-72.
    [184]Chandraseker K, Mukherjee S. Atomistic-continuum and ab initio estimation of the elastic moduli of single-walled carbon nanotubes [J]. Computational Materials Science,2007, 40(1):147-158.
    [185]Park J Y, Im S. Adaptive nonlocal quasicontinuum for deformations of curved crystalline structures [J]. Physical Review B,2008,77(18):184109.
    [186]Marian J, Knap J, Ortiz M. Nanovoid cavitation by dislocation emission in Aluminum [J]. Physical Review Letters,2004,93(16):165503.
    [187]Marian J, Knap J, Campbell G H. A quasicontinuum study of nanovoid collapse under uniaxial loading in Ta [J]. Acta Materialia,2008,56(10):2389-2399.
    [188]Sun X Z, Chen S J, Cheng K, Huo D H, Chu W J. Multiscale simulation on nanometric cutting of single crystal copper [J]. Proceedings of the Institution of Mechanical Engineers, Part B:Journal of Engineering Manufacture,2006,220(7):1217-1222.
    [189]Bamber M J, Cooke K E, Mann A B, Derby B. Accurate determination of Young's modulus and Poisson's ratio of thin films by a combination of acoustic microscopy and nanoindentation [J]. Thin Solid Films,2001,398-399:299-305.
    [190]Bhushan B, Koinkar V N. Nanoindentation hardness measurements using atomic force microscopy [J]. Applied Physics Letters,1994,64 (13):1653-1655.
    [191]Chen J, Bull S J. Assessment of the toughness of thin coatings using nanoindentation under displacement control [J]. Thin Solid Films,2006,494(1-2):1-7.
    [192]Sangwal K, Gorostiza P, Sanz F. Atomic force microscopy study of nanoindentation creep on the (100) face of MgO single crystals [J]. Surface Science,2000,446(3):314-322.
    [193]Shankar M R. Surface steps lead to heterogeneous contact mechanics and facilitate dislocation nucleation in nanoindentation [J]. Applied Physics Letters,2007,90:171924.
    [194]Yang B, Vehoff H. Dependence of nanohardness upon indentation size and grain size-A local examination of the interaction between dislocations and grain boundaries [J]. Acta Materialia,2007,55(3):849-856.
    [195]Soifer Y M, Verdyan A, Kazakevich M, Rabkin E. Nanohardness of copper in the vicinity of grain boundaries [J]. Scripta Materialia,2002,47(12):799-804.
    [196]Gannepalli A, Mallapragada S K. Atomistic studies of defect nucleation during nanoindentation of Au (001) [J]. Physical Review B,2002,66(10):104103.
    [197]Jarausch K F, Kiely J D, Houston J E, Russell P E. Defect-dependent elasticity: nanoindentation as a probe of stress state [J]. Journal of Materials Research,2000,15(8): 1693-1701.
    [198]Smith R, Christopher D, Kenny S D, Richter A, Wolf B. Defect generation and pileup of atoms during nanoindentation of Fe single crystals [J]. Physical Review B,2003,67(24): 245405.
    [199]Van Vliet K J, Li J, Zhu T, Choi Y J, Yip S, Suresh S. Defect nucleation-Predictions through nanoscale experiments and computations [J]. Solid Mechanics and Its Applications, 2004,115:203-211.
    [200]Ercolessi F, Adams J B. Interatomic potentials from first-principles calculations:the force-matching method [J]. Europhysics letters,1994,26(8):583-588.
    [201]Minor A M, Lilleodden E T, Stach E A, Morris J W. Direct observations of incipient plasticity during nanoindentation of Al [J]. Journal of Materials Research,2004,19(1): 176-182.
    [202]Hirth J P, Lothe J. Theory of dislocations. New York:John Wiley and Sons,1982
    [203]Kosugi T, Kino T. A new internal friction peak and the problem of the Peierls potential in f.c.c. metals [J]. Materials Science and Engineering A,1993,164(1-2):368-372.
    [204]Siegel R W, Fougere G E. Mechanical properties of nanophase materials [J]. Nanostructured Materials,1995,6(1-4):205-216.
    [205]Nowak R, Li C L, Maruno S. Low-load indentation behavior of HfN thin films deposited by reactive RF sputtering [J]. Journal of Materials Research,1997,12(1):64-69.
    [206]Mirshams R A, Pothapragada R M. Correlation of nanoindentation measurements of nickel made using geometrically different indenter tips [J]. Acta Materialia,2006,54(4): 1123-1134.
    [207]Qin J, Huang Y, Hwang K C, Song J, Pharr G M. The effect of indenter angle on the microindentation hardness [J]. Acta Materialia,2007,55 (18):6127-6132.
    [208]Viassak J J, Nix W D. Measuring the elastic properties of anisotropic materials by means of indentation experiments [J]. Journal of the Mechanics and Physics of Solids,1994, 42(8):1223-1245.
    [209]Kim J Y, Kang S K, Greer J R, Kwon D. Evaluating plastic flow properties by characterizing indentation size effect using a sharp indenter [J]. Acta Materialia,2008,56 (14): 3338-3343.
    [210]Shim S, Bei H, George E P, Pharr G M. A different type of indentation size effect [J]. Scripta Materialia,2008,59 (10):1095-1098.
    [211]Groenou V, Broese A, Kadijk S E. Slip patterns made by sphere indentations on single crystal MnZn ferrite [J]. Acta Metallurgica, 1989,37(10):2613-2624.
    [212]Khan M Y, Brown L M, Chaudhri M M. Effect of crystal orientation on the indentation cracking and hardness of MgO single crystals [J]. Journal of Physics D:Applied Physics, 1992,25(1A):A257-A265.
    [213]Nix W D. Mechanical properties of thin films [J]. Metallurgical and Materials Transactions A,1989,20 (11):2217-2245.
    [214]Feng G, Nix W D. Indentation size effect in MgO [J]. Scripta Materialia,2004,51(6): 599-603.
    [215]Durst K, Backes B, Goken M. Indentation size effect in metallic materials:correcting for the size of the plastic zone [J]. Scripta Materialia,2005,52(11):1093-1097.
    [216]Shenoy V B, Phillips R, Tadmor E B. Nucleation of dislocations beneath a plane strain indenter [J]. Journal of the Mechanics and Physics of Solids,2000,48(4):649-673.
    [217]Voter A F. The embedded atom method. In:Westbrook J H, Fleischer R L. Intermetallic Compounds: Principles, Vol.1. Wiley, New York,1994:77.
    [218]Liu Y, Wang B, Yoshino M, Roy S, Lu H, Komanduri R. Combined numerical simulation and nanoindentation for determining mechanical properties of single crystal copper at mesoscale [J]. Journal of the Mechanics and Physics of Solids,2005,53(12): 2718-2741.
    [219]Van Vliet K J, Li J, Zhu T, Yip S, Suresh S. Quantifying the early stages of plasticity through nanoscale experiments and simulations [J]. Physical Review B,2003,67(10): 104105.
    [220]Gouldstone A, Koh H J, Zeng K Y, Giannakopoulos A E, Suresh S. Discrete and continuous deformation during nanoindentation of thin films [J]. Acta Materialia,2000,48(9): 2277-2295.
    [221]Yu H H, Shrotriya P, Gao Y F, Kim K S. Micro-plasticity of surface steps under adhesive contact: Part I-Surface yielding controlled by single-dislocation nucleation [J]. Journal of the Mechanics and Physics of Solids,2007,55(3):489-516.
    [222]Abu Al-Rub R K, Voyiadjis G Z. Analytical and experimental determination of the material intrinsic length scale of strain gradient plasticity theory from micro- and nano-indentation experiments [J]. International Journal of Plasticity,2004,20(6):1139-1182.
    [223]Ma Q, Clarke D R. Size dependent hardness of silver single crystals [J]. Journal of Materials Research,1995,10(4):853-863.
    [224]Rice J R, Thomson R. Ductile versus brittle behavior of crystals [J]. Philosophical Magazine A,1974,29(1):73-97.
    [225]Johnson K L. Contact Mechanics. Cambridge:Cambridge University Press,1985.
    [226]Tsuru T, Shibutani Y. Anisotropic effects in elastic and incipient plastic deformation under (001), (110), and (111) nanoindentation of Al and Cu [J]. Physical Review B,2007,75 (3):035415.
    [227]Cammarata R C, Schlesinger T E, Kim C, Qadri S B, Edelstein A S. Nanoindentation study of the mechanical properties of copper-nickel multilayered thin films [J]. Applied Physics Letters,1990,56(19):1862-1864.
    [228]Li X D, Bhushan B. Micro/nanomechanical and tribological studies of bulk and thin-film materials used in magnetic recording heads [J]. Thin Solid Films,2001,389-399: 313-319.
    [229]Li X D, Bhushan B. Micromechanical and tribological characterization of hard amorphous carbon coatings as thin as 5 nm for magnetic recording heads [J]. Wear,1998, 220(1):51-58.
    [230]Bhushan B, Gupta B K, Azarian M H. Nanoindentation, microscratch, friction and wear studies of coatings for contact recording applications [J]. Wear,1995,181-183:743-758.
    [231]Dewald M P, Curtin W A. Multiscale modeling of dislocation/grain-boundary interactions:I. Edge dislocations impinging on ∑11 (113) tilt boundary in Al [J]. Modelling and Simulation in Materials Science and Engineering,2007,15:S193-S215.
    [232]Yao Y G, Wang T. Peierls-Nabarro model of interfacial misfit dislocation:An analytic solution [J]. Physical Review B,1999,59(12):8232-8236.
    [233]Yao Y G, Wang T. The modified Peierls-Nabarro model of interfacial misfit dislocation [J].Acta Materialia,1999,47(10):3063-3068.
    [234]McKeown J, Misra A, Kung H, Hoagland R G, Nastasi M. Microstructures and strength of nanoscale Cu-Ag multilayers [J]. Scripta Materialia,2002,46(8):593-598.
    [235]Misra A, Hirth J P, Kung H. Single-dislocation-based strengthening mechanisms in nanoscale metallic multilayers [J]. Philosophical Magazine A,2002,82(16):2935-2951.
    [236]Huang H B, Spaepen F. Tensile testing of free-standing Cu, Ag and Al thin films and Ag/Cu multilayers [J]. Acta Materialia,2000,48(12):3261-3269.
    [237]Schweitz K O, Chevallier J, Bottiger J. Hardness in Ag/Ni, Au/Ni and Cu/Ni multilayers [J]. Philosophical Magazine A,2001,81(8):2021-2032.
    [238]Chen S H, Liu L, Wang T C. Size dependent nanoindentation of a soft film on a hard substrate [J]. Acta Materialia,2004,52(5):1089-1095.
    [239]Chen S H, Liu L, Wang T C. Investigation of the mechanical properties of thin films by nanoindentation, considering the effects of thickness and different coating-substrate combinations [J]. Surface and Coatings Technology,2005,191(1):25-32.
    [240]Chen S H, Liu L, Wang T C. Small scale, grain size and substrate effects in nano-indentation experiment of film-substrate systems [J]. International Journal of Solids and Structures,2007,44(13):4492-4504.
    [241]Hall E O. The deformation and ageing of mild steel:III dislocation of results [J]. Proceedings of the Physical Society, Section B.1951,64(9):747-753.
    [242]Panich N, Sun Y. Effect of penetration depth on indentation response of soft coatings on hard substrates:a finite element analysis [J]. Surface and Coatings Technology,2004, 182(2-3):342-350.
    [243]Pelegri A A, Huang X Q. Nanoindentation on soft film/hard substrate and hard film/soft substrate material systems with finite element analysis [J]. Composites Science and Technology,2008,68(1):147-155.
    [244]Lilleodden E T, Zimmerman J A, Foiles S M, Nix W D. Atomistic simulations of elastic deformation and dislocation nucleation during nanoindentation [J]. Journal of the Mechanics and Physics of Solids,2003,51(5):901-920.
    [245]Spearot D E, Jacob K I, McDowell D L. Nucleation of dislocations from [001] bicrystal interfaces in aluminum [J]. Acta Materialia,2005,53(13):3579-3589.
    [246]Saraev D, Miller R E. Atomic-scale simulations of nanoindentation-induced plasticity in copper crystals with nanometer-sized nickel coatings [J]. Acta Materialia,2006,54(1):33-45.
    [247]Medyanik S N, Shao S. Strengthening effects of coherent interfaces in nanoscale metallic bilayers [J]. Computational Materials Science,2009,45(4):1129-1133.
    [248]Hoagland R G, Kurtz R J, Henager Jr C H. Slip resistance of interfaces and the strength of metallic multilayer composites [J]. Scripta Materialia,2004,50(6):775-779.
    [249]Cheng D, Yan Z J, Yan L. Molecular dynamics simulation of strengthening mechanism of Cu/Ni multilayers [J]. Acta Metallurgica Sinca,2008,44(12):1461-1464.
    [250]Petch N J. The cleavage of polycrystals [J]. Journal of the Iron and Steel Institute,1953, 174:25-28.
    [251]Chokshi A H, Rosen A, Karch J, Gleiter H. On the validity of the hall-petch relationship in nanocrystalline materials [J]. Scripta Metallurgica,1989,23(10):1679-1683.
    [252]Nieh T G, Wadsworth J. Hall-petch relation in nanocrystalline solids [J]. Scripta Metallurgica et Materialia,1991,25(4):955-958.
    [253]Schiφtz J, Di Tolla F D, Jacobsen K W. Softening of nanocrystalline metals at very small grain sizes [J]. Nature,1998,391:561-563.
    [254]Van Swygenhoven H. Grain boundaries and dislocations [J]. Science,2002,296:66-67.
    [255]Van Swygenhoven H, Spaczer M, Caro A, Farkas D. Competing plastic deformation mechanisms in nanophase metals [J]. Physical Review B,1999,60(1):22-25.
    [256]Schiφtz J, Jacobsen K W. A maximum in the strength of nanocrystalline copper [J]. Science,2003,301:1357-1359.
    [257]Van Swygenhoven H, Derlet P M, Frφseth A G. Stacking fault energies and slip in nanocrystalline metals [J]. Nature Materials,2004,3:399-403.
    [258]Saraev D, Miller R E. Atomistic simulation of nanoindentation into copper multilayers [J]. Modelling Simulation in Materials Science and Engineering,2005,13(7):1089-1099.
    [259]Lim Y Y, Chaudhri M M. Accurate determination of the mechanical properties of thin aluminum films deposited on sapphire flats using nanoindentations, Journal of Materials Research,1999,14(6):2314-2327.
    [260]Simmons G, Wang H. Single crystal elastic constants and calculated aggregate properties. Cambridge:MIT Press,1971.

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