Laser Shock Based Controlled Forming of Silver Nanowires

Author(s):  
Ji Li ◽  
Yiliang Liao ◽  
Gary J. Cheng

One-dimensional nanomaterials have attracted a great deal of research interest in the past few decades due to their unique mechanical, electrical and optical properties. Changing the shape of nanowires is a big challenge, but remains key for realistic applications of nanowires. Here we report a general technique to flexibly form nanowires into different shapes by making use of laser shock pressure. Controllable deformation is induced into nanowires in a similar manner as traditional metal forming. Shaping of silver nanowires is demonstrated, during which the Ag nanowires exhibit very good ductility (strain to failure is larger than 1). The microstructure observation indicates that the main deformation mechanism in Ag nanowires under dynamic loading is controlled by twinning and stacking fault formation. Dislocation motion and pile-up is still operative but less important. Our method provides a simple, unique, and one-step approach in massive forming and machining nanowires.

Nanomaterials ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 376 ◽  
Author(s):  
Luhang Xu ◽  
Dengpo Huang ◽  
Huimei Chen ◽  
Xiaoling Jing ◽  
Jiale Huang ◽  
...  
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2011 ◽  
Vol 399-401 ◽  
pp. 144-147
Author(s):  
Hai Yan Wang ◽  
Hui Ping Ren ◽  
Zong Chang Liu

Microstructure evolution of Fe-1.18%Cu high purity steels during solution and aging was investigated under high-resolution electron microscope (HREM). In addition, the aging strengthening mechanisms were discussed based on the microstructure observation. The results show that there were lots of Cu atom clusters in ferrite matrix during solid solution and aging initial stages, subsequently, Cu-rich metastable Fe-Cu particles precipitate at the aging strength peak. It is found that the intense strengthening is controlled by the coherency relationship of Fe-Cu metastable phase with matrix that forms the obstacle of the dislocation motion, while the decrease of strength after the peak is attributed to the loss of coherency, which should highly likely be the dominant reason of aging strengthening in Cu bearing high purity steels Thus our TEM observation results are in reasonably agreement with some previous assume.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2108
Author(s):  
Robert Texidó ◽  
Salvador Borrós

In this paper, we report a one-step method to obtain conductive polypyrrole thin films on flexible substrates. To do this, substrates were modified through allylamine plasma grafting to create a high amount of reactive amine groups on PDMS surface. These groups are used during polypyrrole particle synthesis as anchoring points to immobilize the polymeric chains on the substrate during polymerization. Surface morphology of polypyrrole thin films are modified, tailoring the polyelectrolyte used in the polypyrrole synthesis obtaining different shapes of nanoparticles that conform to the film. Depending on the polyelectrolyte molecular weight, the shape of polypyrrole particles go from globular (500 nm diameter) to a more constructed and elongated shape. The films obtained with this methodology reflected great stability under simple bending as well as good conductivity values (between 2.2 ± 0.7 S/m to 5.6 ± 0.2 S/cm).


2019 ◽  
Vol 6 (7) ◽  
pp. 075050 ◽  
Author(s):  
Diksha Sharma ◽  
D Aarthi Rakshana ◽  
Raj Mohan Balakrishnan ◽  
P E JagadeeshBabu

2008 ◽  
Vol 23 (11) ◽  
pp. 2916-2934 ◽  
Author(s):  
K.S. Kumar ◽  
L. Reinbold ◽  
A.F. Bower ◽  
E. Chason

Although the driving force for the growth of Sn whiskers from the surface of Sn coatings on copper is thought to be internally generated stress due to the formation of Cu6Sn5 at the Cu/Sn interface, little is known about the nature of this internal stress and how it cracks the surface Sn oxide (an important precursor to whisker formation). Arguments based on elasticity alone do not appear to be sufficient and suggest an important role for plastic deformation. Direct observations, made by transmission electron microscopy of cross-sectioned bimetallic Cu/Sn thin-film specimens, confirm plastic deformation of the Sn grains due to the formation of Cu6Sn5. Dislocation motion and pile-up at the surface Sn oxide, rotation associated with subgrain boundary formation, interaction of the subgrain boundaries with the Sn surface, and diffusional processes are various mechanisms that can produce stress at the Sn surface and crack the Sn oxide.


Author(s):  
Jiangjiang Hu ◽  
Weiming Sun ◽  
Taihua Zhang ◽  
Yusheng Zhang

At room temperature, the indentation morphologies of crystalline copper with different grain size including nanocrystalline (NC), ultrafine-grained (UFG) and coarse-grained (CG) copper were studied by nanoindentation at the strain rate of 0.04/s without holding time at indentation depth of 2000 nm. As the grain size increasing, the height of the pile-up around the residual indentation increases and then has a slightly decrease in the CG Cu, While the area of the pile-up increases constantly. Our analysis has revealed that the dislocation motion and GB activities in the NC Cu, some cross- and multiple-slips dislocation insides the larger grain in the UFG Cu, and forest dislocations from the intragranular Frank-Read sources in the CG Cu, would directly induce these distinct pile-up effect.


Nanoscale ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 3606-3618 ◽  
Author(s):  
Nitin M. Batra ◽  
Ahad Syed ◽  
Pedro M. F. J. Costa

The electrical and structural responses of suspended Ag nanowires, subjected to an increasing flow of current, relate highly to their geometric configuration.


2019 ◽  
Vol 7 (24) ◽  
pp. 20102-20106 ◽  
Author(s):  
Yuchu He ◽  
Kang Niu ◽  
Liyao Luo ◽  
Lei Li ◽  
Cong Cong ◽  
...  

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