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Title:: Size Effects on the Strengthening/Toughening of Nanostructured Metallic Multilayers

Author(s):: ZHANG Jinyu; LIU Gang; SUN Jun; State Key Laboratory for Mechanical Behavior of Materials, Xi‘a(chǎn)n Jiaotong University

摘要:: 如何有效地協(xié)調(diào)和平衡材料強(qiáng)度與韌性之間的矛盾, 大幅度地提高結(jié)構(gòu)材料的損傷容限, 是非均質(zhì)金屬材料微觀結(jié)構(gòu)敏感性設(shè)計(jì)的巨大挑戰(zhàn)。納米金屬多層膜作為一類典型的非均質(zhì)金屬材料，由于不僅可以調(diào)整其組元幾何和微觀結(jié)構(gòu)尺度，而且可以引入具有不同本征性能的組元材料和不同結(jié)構(gòu)的層間異質(zhì)界面，因此在獲得高強(qiáng)高韌金屬結(jié)構(gòu)材料方面具有潛在的能力。結(jié)合當(dāng)前國(guó)內(nèi)外有關(guān)金屬多層膜塑性變形強(qiáng)韌化機(jī)制及其尺寸與界面效應(yīng)研究的最新進(jìn)展, 分別闡述了晶體/晶體Cu/X（X=Cr, Nb, Zr)與晶體/非晶Cu/Cu-Zr金屬多層膜/微柱微觀結(jié)構(gòu)-尺寸約束-服役性能三者之間的關(guān)聯(lián)性, 并對(duì)納米金屬多層膜研究的發(fā)展趨勢(shì)進(jìn)行了展望。

Abstract:: How to defeat the conflict of strength vs toughness and achieve unprecedented levels of damage tolerance within structural materials is a grand challenge for their microstructuresensitive design of heterogeneous metallic materials. Nanostructured metallic multilayers act as one class of typical heterogeneous materials and manifest great potential to obtain the structural materials with the combination of high strength and superior toughness, due to their tunable dimensional and microstructural length of the constituents as well the great advantage of tunable interfacial structures via introducing different constituents. The present authors had systematically investigated the size and interface effects on the mechanical properties, such as hardness/strength, tensile ductility, fracture toughness, and strengthening/toughening mechanisms of crystalline/crystalline Cu/X (X=Cr, Nb, Zr) and crystalline/amorphous Cu/CuZr nanolayered films/micropillars. In this paper, based on these experimental results achieved by the present authors, as well as the progresses at home and abroad made in the plastic deformation behavior of NMMs, the correlation of microstructuresize constraintmechanical performance in NMMs (and nanolayered micropillars) is reviewed. Finally, a brief prospect on the studies of NMMs in future is discussed.