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Full-Text Articles in Nanoscience and Nanotechnology

Large Scale, Highly Dense Nanoholes On Metal Surfaces By Underwater Laser Assisted Hydrogen Etching Near Nanocrystalline Boundary, Dong Lin, Martin Yi Zhang, Chang Ye, Zhikun Liu, Richard Liu, Gary Cheng Aug 2014

Large Scale, Highly Dense Nanoholes On Metal Surfaces By Underwater Laser Assisted Hydrogen Etching Near Nanocrystalline Boundary, Dong Lin, Martin Yi Zhang, Chang Ye, Zhikun Liu, Richard Liu, Gary Cheng

dong lin

A new method to generate large scale and highly dense nanoholes is presented in this paper. By the pulsed laser irradiation under water, the hydrogen etching is introduced to form high density nanoholes on the surfaces of AISI 4140 steel and Ti. In order to achieve higher nanohole density, laser shock peening (LSP) followed by recrystallization is used for grain refinement. It is found that the nanohole density does not increase until recrystallization of the substructures after laser shock peening. The mechanism of nanohole generation is studied in detail. This method can be also applied to generate nanoholes on other …


Laser Assisted Embedding Of Nanoparticles Into Metallic Materials, Dong Lin, Sergey Suslov, Chang Ye, Yiliang Liao, C. Richard Liu, Gary Cheng Aug 2014

Laser Assisted Embedding Of Nanoparticles Into Metallic Materials, Dong Lin, Sergey Suslov, Chang Ye, Yiliang Liao, C. Richard Liu, Gary Cheng

dong lin

This paper reports a methodology of half-embedding nanoparticles into metallic materials. Transparent and opaque nanoparticles are chosen to demonstrate the process of laser assisted nanoparticle embedding. Dip coating method is used to coat transparent or opaque nanoparticle on the surface of metallic material. Nanoparticles are embedded into substrate by laser irradiation. In this study, the mechanism and process of nanoparticle embedding are investigated. It is found both transparent and opaque nanoparticles embedding are with high densities and good uniformities. (C) 2011 Elsevier B. V. All rights reserved.


Magnetic Field Assisted Growth Of Highly Dense Alpha-Fe2o3 Single Crystal Nanosheets And Their Application In Water Treatment, Dong Lin, Biwei Deng, Stephen Sassman, Yaowu Hu, Sergey Suslov, Gary Cheng Aug 2014

Magnetic Field Assisted Growth Of Highly Dense Alpha-Fe2o3 Single Crystal Nanosheets And Their Application In Water Treatment, Dong Lin, Biwei Deng, Stephen Sassman, Yaowu Hu, Sergey Suslov, Gary Cheng

dong lin

Highly dense 2D nanostructures are desirable in photocatalysis, water treatment and energy storage, due to their high surface to volume areas. This paper describes a novel approach combining thermal stress and magnetic force to generate highly dense alpha-Fe2O3 nanosheets on the surface of various iron substrates, including plates and powders. This technique involves the thermal oxidation of iron substrates on a hot plate with a magnetic field. The Lorentz force acting on the ions induced by the magnetic field facilitates the lateral growth of nanosheets. This effect results in a highly porous nanostructure consisting of dense 2D nanosheets with extremely …


Mechanism Of Fatigue Performance Enhancement In A Laser Sintered Superhard Nanoparticles Reinforced Nanocomposite Followed By Laser Shock Peening, Dong Lin, Chang Ye, Yiliang Liao, Sergey Suslov, Richard Liu, Gary J. Cheng Aug 2014

Mechanism Of Fatigue Performance Enhancement In A Laser Sintered Superhard Nanoparticles Reinforced Nanocomposite Followed By Laser Shock Peening, Dong Lin, Chang Ye, Yiliang Liao, Sergey Suslov, Richard Liu, Gary J. Cheng

dong lin

This study investigates the fundamental mechanism of fatigue performance enhancement during a novel hybrid manufacturing process, which combines laser sintering of superhard nanoparticles integrated nanocomposites and laser shock peening (LSP). Through laser sintering, TiN nanoparticles are integrated uniformly into iron matrix to form a nanocomposite layer near the surface of AISI4140 steel. LSP is then performed on the nanocomposite layer to generate interaction between nanoparticles and shock waves. The fundamental mechanism of fatigue performance enhancement is discussed in this paper. During laser shock interaction with the nanocomposites, the existence of nanoparticles increases the dislocation density and also helps to pin …


Direct Writing Of Au Nanoneedles Array On Glass By Confined Laser Spinning, Yingling Yang, Dong Lin, Gary J. Cheng Aug 2014

Direct Writing Of Au Nanoneedles Array On Glass By Confined Laser Spinning, Yingling Yang, Dong Lin, Gary J. Cheng

dong lin

Generation of gold nanoneedles on glass by confined laser spinning was explored by using a nanosecond pulsed laser. When the coated Au thin film was irradiated under the confinement of glass, gold nanoneedles were formed by spreading the molten liquid of gold under high pressure. The mechanism of the confined laser spinning process is studied. The maximum velocity and instability of molten liquid during confined laser spinning were estimated. The diameter of nanoneedles can be controlled by changing the thickness of coated gold thin film. Large scale of gold nanoneedles can be formed by this direct writing method and collected …


Laser Sintering Of Separated And Uniformly Distributed Multiwall Carbon Nanotubes Integrated Iron Nanocomposites, Dong Lin, Chunghorng Richard Liu, Gary J. Cheng Aug 2014

Laser Sintering Of Separated And Uniformly Distributed Multiwall Carbon Nanotubes Integrated Iron Nanocomposites, Dong Lin, Chunghorng Richard Liu, Gary J. Cheng

dong lin

Uniform distribution of carbon nanotubes (CNTs) in metal matrix during additive manufacturing of nanocomposites is always a challenge since the CNTs tend to aggregate in the molten pool. In this study, Multiwall carbon nanotubes (MWNTs) were separated and distributed uniformly into iron matrix by laser sintering process. MWNTs and iron powders were mixed together by magnetic stir, coated on steel 4140 surface, followed by laser sintering. Due to the fast heating and cooling rate, the CNTs are evenly distributed in the metal matrix. The temperature field was calculated by multiphysics simulation considering size effects, including size dependent melting temperature, thermal …