Size effect of deformation nanotwin bundles on their strengthening and toughening in heterogeneous nanostructured Cu  

作　　者：YOU ZeSheng LUO ShuSen LU Lei 

机构地区：[1]Herbert Gleiter Institute of Nanoscience,Nanjing University of Science and Technology,Nanjing 210094,China [2]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China

出　　处：《Science China(Technological Sciences)》2021年第1期23-31,共9页中国科学（技术科学英文版）

基　　金：supported by the National Key R&D Program of China(Grant No. 2017YFA0204403);financial support from the National Natural Science Foundation of China (Grant Nos. U1608257and 51931010);the Key Research Program of Frontier Science and the International Partnership Program (Grant No. GJHZ2029);Chinese Academy of Sciences,and Liaoning Revitalization Talents Program (Grant No. XLYC1802026)。

摘　　要：Herein, we fabricated a heterogeneous nanostructured Cu with deformation nanotwin bundles(NTBs) embedded in a matrix of nanograins by means of dynamic plastic deformation at liquid nitrogen temperature. We conducted fracture mechanical measurements to investigate the effect of longitudinal length of the NTBs on their strengthening and toughening. Results suggest that an increase in the NTB length had a marginal influence on the tensile strength;however, it remarkably promoted both fracture initiation toughness and crack growth toughness. Longer NTBs are more effective not only in intrinsically enhancing crack tip plasticity by suppressing the strain localization and void nucleation but also in serving as crack bridges behind the crack front to extrinsically resist the fracture by shielding the crack tip.

关 键 词：fracture toughness NANOTWINS J-INTEGRAL size effect toughening mechanism 

分 类 号：TG146.11[一般工业技术—材料科学与工程] TB383.1[金属学及工艺—金属材料]