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Microstructure and Mechanical Properties of Fe-based Amorphous Composite Coatings Reinforced by Stainless Steel Powders

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Journal of Materials Science & Technology 2015年第1期31卷 43-47页

作者： H.Zhou C.Zhang W.Wang M.Yasir l.liu School of Materials Science and Engineering State Key Lab for Materials Processing and Die &Mould TechnologyHuazhong University of Science and Technology Huazhong University of Science and Technology Research Institute in Shenzhen

In this study,a few Fe-based amorphous matrix composite coatings reinforced with various portions(4,8 and16 vol.%) of 31 6l stainless steel powders have been successfully produced through high velocity oxy-fuel(HVOF) *** microstructure of the composite coatings was systematically characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The main structure of composite coatings remained amorphous while 31 6l stainless steel splats were distributed homogeneously in the amorphous matrix and well connected with surrounding amorphous *** strength of coatings to the substrate was determined by 'pull-off' tensile *** results revealed that the31 6l stainless steel phase effectively improved the bonding strength of amorphous coatings,which is mainly contributed by the strong metallurgical bonding between stainless steel and amorphous *** addition of31 6l stainless steel also enhanced the ductility and fracture resistance of the coatings due to the ductile stainless steel phases,which can arrest crack propagation and increase energy dissipation.

关键词： Thermal spraying Fe-based amorphous coating Stainl

Microstructure of Nitrided Aluminum Alloys Using an Electron-Beam-Excited-Plasma (EBEP)

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材料热处理学报 2004年第5期25卷 349-353页

作者： l.liu A.Yamamoto T.Hishida H.Shoyama T.Hara H.Tsubakino GraduateSchool UniversityofHyogo2167ShoshaHimeji671-2201Japan FaultyofEngineering ToyotaTechnologicalInstituteNagoya468-8511Japan

Nitriding of surface of aluminum alloys was carried out with using an electron-beam-excited-plasma (EBEP) technique. The EBEP is sustained by electron impact ionization with energetic electron beam. Two kinds of substrates, aluminum alloys AA5052 and AA5083, were exposed to the down flow of EBEP source at 843 K for 45min. The specimens were characterized with respect to following properties: crystallographic structure (XRD), morphology (SEM) and the cross sectional microstructures of the nitrided layer was observed using a scanning electron microscopy (SEM). There are some A12O3 particles on the surface of the nitrided AA5052 and AA5083. The A1N layers were formed on the substrates with the thickness of 4.5 fi m for AA5052 and 0.5 /z m for AA5083 . A relatively uniform nitrided surface layer composed of A1N can be observed on the AA5052 substrate. The grains size near the interfaces between the substrate and A1N layer were smaller than that near the surface. On the surface of A1N layer, the concentration of nitrogen was high and in the middle of A1N layer it had a constant concentration like the aluminum and the concentration was decreased with approaching to the interface. On the surface of nitrided AA5083, a uniform A1N layer was not formed as the reason for the high nitriding temperature.

关键词：显微结构铝合金渗氮 EBEP

Nano Brazing of Pt-Ag Nanoparticles under Femtosecond laser Irradiation

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Nano-Micro letters 2013年第2期5卷 88-92页

作者： l.liu H.Huang A.Hu G.Zou l.Quintino Y.Zhou Department of Mechanical Engineering Tsinghua University Department of Mechanical & Mechatronics Engineering University of Waterloo Technical University of lisbon

Nano brazing of Pt-Ag nanoparticles with nano Ag filler metal is reported in this letter, which presents an effective way to join nanoobjects by femtosecond laser irradiation. The nano brazed interface between Pt-Ag and Ag showed good lattice matching along(111)_(Ag) //(111)_(Ag-Pt). lattice mismatch can hardly be observed at the interface between the filler metal and Pt-Ag nanoparticle, which is important for the joint strength and normally does not occur during joining. The very low mismatch also suggested that melting and solidification occurred during nano brazing by femtosecond laser. The role of Brownian motion on the nano joining process is also discussed in this paper.

关键词： Femtosecond laser Nanojoining Nanoparticles

Effect of Cold-Rolling on Precipitation Phenomena in Sensitized Type 316l and 304l Austenitic Stainless Steels

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材料热处理学报 2004年第5期25卷 217-222页

作者： H.Tsubakino A.Yamamoto T.Yamada l.liu M.Terasawa S.Nakahigashi H.Harada GraduateSchoolofEngineering UniversityofHyogoHimejiHyogoJapan GraduateStudent UniversityofHyogoHimejiHyogoJapan JapanPowerEngineeringandInspectionCo. YokohamaKanagawaJapan Koyo-SeikoCo.ltd. KashiwaraOsakaJapan

Precipitation phenomena in Type 316l and 304l stainless steels were studied mainly by transmission electron microscopic (TEM) observations after cold-rolling ranging from 0% (as solution annealed) to 80% reduction in thickness, and then by sensitization treatment. Precipitates were identified by electron diffraction analysis and EDS analysis. Precipitates observed in sensitized 316l stainless steel were sigma and chi phases, whereas carbide and sigma were observed in sensitized 304l stainless steel. Recrystallized grains were formed in 30% cold-rolled and sensitized 304l. However, the tendency toward recrystallization in sensitized 316l was much lower than in 304l. Precipitation of sigma and chi phases was accelerated by cold-rolling and they were observed at grain boundaries in lower cold-rolling; they were also seen, in grain interiors in higher cold-rolling. Higher deformation induced partially recrystallization combined with precipitation, resulting in the formation of heterogeneous microstructures.

关键词：冷轧 316l 304l 奥氏体不锈钢 TEM

Dynamics of N^(5+)-H electron capture in Debye plasmas

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Matter and Radiation at Extremes 2016年第2期1卷 114-122页

作者： l.liu J.G.Wang Data Center for High Energy Density Physics Institute of Applied Physics and Computational MathematicsP.O.Box 8009-26Beijing100088People's Republic of China

The electron capture in N^(5+)-H collisions imbedded in a Debye plasma is studied by using the two-center atomic orbital close-coupling method in the energy range from 1 keV/u to 200 keV/*** atomic orbitals and electron binding energies of atomic states are calculated within the Debye-Huckel approximation of the screened Coulomb potential and used in atomic orbital close-coupling dynamics formalism to calculate the electron capture cross *** electron capture cross sections and the charge transfer spectral lines of N^(4+)(1s^(2)nl)for a number of representative screening parameter values are presented and *** is found that the screening of Coulomb interactions affects the entire collision dynamics and the magnitude and energy behavior of state-selective cross *** changes in electron binding energies and capture cross sections when the interaction screening varies introduce dramatic changes in the radiation spectrum of N^(4+)(1s^(2)nl)capture states with respect to the unscreened interaction case.

关键词： Electron capture Debye plasma Screening Atomic orbital close-coupling

Unexpected creep behavior in a rejuvenated metallic glass

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Journal of Materials Science & Technology 2023年第32期163卷 140-149页

作者： J.P.Wu Y.lin F.H.Duan Q.Chen H.T.Wang N.li J.l.Wen J.Pan l.liu Shenyang National laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China State Key laboratory of Material Processing and Die&Mould Technology and School of Materials Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China laboratory of Nanomaterials&Nanomechanics Department of Mechanical EngineeringCity University of Hong KongHong KongChina Wuhan National High Magnetic Field Center Huazhong University of Science and TechnologyWuhan 430074China Shenzhen Polytechnic Shenzhen 518055China

Rejuvenation,bringing metallic glasses(MGs)to the younger and higher energy states,provides an alternative avenue to explore the interplay between the property and microstructures of *** this study,the creep behavior of the Zr_(69.5)Cu_(12)Ni_(11)Al_(7.5)MGs was experimentally examined by controlling the energy state in terms of structural rejuvenation and thermal *** is found that compared to the as-cast counterpart,the annealed MG at a lower energy state exhibits a higher hardness,a smaller displacement,and a lower creep rate due to the decreased free volume and the inhibited activation of the shear transformation ***,the rejuvenated MG at a high energy state displays lower hardness and increased free volume content,yet it demonstrates superior creep resistance compared to its as-cast counterpart,which deviates from conventional *** unexpected phenomenon occurs as the initial high-content free volume annihilates during creep,and strain hardening takes precedence over strain softening as the prevailing process during creep deformation,leading to a superior creep performance in extremely rejuvenated MGs.

关键词： Metallic glass Energy state Rejuvenation Creep Strain-hardening

Intensities and shifts of lyman and Balmer lines of hydrogen-like ions in high density plasmas

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Matter and Radiation at Extremes 2018年第6期3卷 300-311页

作者： G.P.Zhao l.liu J.G.Wang R.K.Janev J.Yan Institute of Applied Physics and Computational Mathematics P.O.Box 8009-26Beijing 100088China Macedonian Academy of Sciences and Arts P.O.Box 4281000 SkopjeMacedonia

The spectral line intensities and line shifts of lyman and Balmer series for transitions up to n=5 of hydrogen-like ion are studied in plasmas with densities and temperatures in the ranges n_(c)~10^(18)-10^(21)cm^(-3),T_(e)=0.3e1.2 eV *** screened potential used to describe the interaction between charged particles includes the electron exchange-correlation and finite-temperature gradient effects and is valid for both weakly and strongly coupled *** dependencies of alpha,beta and gamma line shifts of lyman and Balmer series on plasma density(for fixed temperature)and temperature(for fixed density)are *** results for the H_(a)line shifts are compared with the available high-density experimental data.

关键词： Screened coulomb interaction Hydrogen-like ion Spectral lines High density plasmas

Study of xonotlite architectural coatings for exterior wall insulation mechanism

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Study of xonotlite architectural coatings for exterior wall ...

NOTES ON SOME MARINE EARlY TRIASSIC lAMEllIBRANCHIATA FROM EAST TSINlING,SOUTHERN SHANXI(SHENSI)

2014中国功能材料科技与产业高层论坛

作者： l.liu J.X.Cao

Thermal insulation exterior wall coating has been successfully prepared,using styrene-acrylic emulsion as film former,and xonotlite as heat-insulat-ing filler,which produced by hydrothermal *** insulation mechanism of xonotlite is explored,through analyzingthe microstructure of homemade xonotlite thermal insulation exterior wall *** results show that xonotlite is a kind of compound type heat-insulating filler that can effectively weakened the heat transfer in the coating,like heat conduction,thermal convection and thermal radiation.

关键词： xonotlite coatings thermal insulation walls mechanism

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古生物学报 1964年第2期 321-325页

作者： l.liu (Institute of Geology and Palaeontology,Academia Sinica)

Some fossils,mainly lamellibranchs,were recently discovered by a field party of theGeological Bureau of Shanxi Province at some 20 km SSE from Zhenan(Chenan)city ineastern *** fossil locality is within the type area of the“Chenan series”(Chaoand Huang,1931)and near to the southern border of the Tsinling *** collectionwas made in a series of grey-black calcareous and slaty shales,the lower part of the“Jin-jiling Qun”.After a careful study on these life-remains,*** and the writerhave arrived at the same conclusion that these fossils are undoubtly of marine *** fauna consists of the following forms:Claraia hunanica(Hsü)*** Chen et liu(***.)***(Patte)*** ***(Bittner)***?***(Goldfuss)Cephalopoda *** *** genera ind.

关键词： NOTES ON SOME MARINE EARlY TRIASSIC lAMEllIBRANCHIATA FROM EAST TSINlING,SOUTHERN SHANXI SHENSI EAST