Focus on face-centered cubic （fcc） metals with nano-scale twins lamellar structure, this paper presents a brief overview of the recent progress made in improving mechanical properties, including strength, ductility,...Focus on face-centered cubic （fcc） metals with nano-scale twins lamellar structure, this paper presents a brief overview of the recent progress made in improving mechanical properties, including strength, ductility, work hardening, strain rate sensitivities, and in mechanistically understanding the underling deformation mechanisms. Significant developments have been achieved in nano-twinned fcc metals with a combination of high strength and considerable ductility at the same time, enhanced work hardening ability and enhanced rate sensitivity. The findings elucidate the role of interactions between dislocations and twin boundaries （TBs） and their contribution to the origin of outstanding properties. The computer simulation analysis accounts for high plastic anisotropy and rate sensitivity anisotropy by treating TBs as internal interfaces and allowing special slip geometry arrangements that involve soft and hard modes of deformation. Parallel to the novel mechanical behaviors of the nano-twinned materials, the investigation and developments of nanocrystalline materials are also discussed in this overview for comparing the contribution of grain boundaries/TBs and grain size/twin lamellar spacing to the properties. The recent advances in the experimental and computational studies of plastic deformation of the fcc metals with nano-scale twin lamellar structures provide insights into the possible means of optimizing comprehensive mechanical properties through interfacial engineering.展开更多
In the last decade,numerous kinds of nanoscale materials have been created.Their characteristics are critically influenced by their synthetic or fabrication methods.In this review article,we introduce perfect crystal ...In the last decade,numerous kinds of nanoscale materials have been created.Their characteristics are critically influenced by their synthetic or fabrication methods.In this review article,we introduce perfect crystal gold nanowires(Au NWs) synthesized by vapor transport method and summarize their material properties and biological applications.Single-crystalline Au NWs having no defects or twins show unique mechanical,electrical,and electrochemical characteristics.Notably,they are exceptionally competent in penetrating cells or tissues with minimum biological damage and in the electrical analysis and manipulation of biological activities in the cells and/or tissues.It is expected that the Au NWs would give us technological breakthrough in diverse applications such as nanoscale functional components as well as new insights in fundamental material science.展开更多
基金the National Natural Science Foundation of China under Grant Nos.50021001,50571096,50725103,MOST of China(Grant No.2005 CB623604).
文摘Focus on face-centered cubic （fcc） metals with nano-scale twins lamellar structure, this paper presents a brief overview of the recent progress made in improving mechanical properties, including strength, ductility, work hardening, strain rate sensitivities, and in mechanistically understanding the underling deformation mechanisms. Significant developments have been achieved in nano-twinned fcc metals with a combination of high strength and considerable ductility at the same time, enhanced work hardening ability and enhanced rate sensitivity. The findings elucidate the role of interactions between dislocations and twin boundaries （TBs） and their contribution to the origin of outstanding properties. The computer simulation analysis accounts for high plastic anisotropy and rate sensitivity anisotropy by treating TBs as internal interfaces and allowing special slip geometry arrangements that involve soft and hard modes of deformation. Parallel to the novel mechanical behaviors of the nano-twinned materials, the investigation and developments of nanocrystalline materials are also discussed in this overview for comparing the contribution of grain boundaries/TBs and grain size/twin lamellar spacing to the properties. The recent advances in the experimental and computational studies of plastic deformation of the fcc metals with nano-scale twin lamellar structures provide insights into the possible means of optimizing comprehensive mechanical properties through interfacial engineering.
基金supported by the Public welfare & Safety research program(NRF-2012M3A2A1051686) through the National Research Foundation of Korea funded by the Ministry of Science,ICT & Future Planning(MSIP)Global Frontier Project(HGUARD_2014M3A6B2060489) through the Center for BioNano Health-Guard funded by the MSIPKRIBB initiative Research Program
文摘In the last decade,numerous kinds of nanoscale materials have been created.Their characteristics are critically influenced by their synthetic or fabrication methods.In this review article,we introduce perfect crystal gold nanowires(Au NWs) synthesized by vapor transport method and summarize their material properties and biological applications.Single-crystalline Au NWs having no defects or twins show unique mechanical,electrical,and electrochemical characteristics.Notably,they are exceptionally competent in penetrating cells or tissues with minimum biological damage and in the electrical analysis and manipulation of biological activities in the cells and/or tissues.It is expected that the Au NWs would give us technological breakthrough in diverse applications such as nanoscale functional components as well as new insights in fundamental material science.
