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Load Dependence of Nanohardness in Nitrogen Ion Implanted Ti6Al4V Alloy and Fractal Characterization 被引量:4
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作者 LUO Yong GE Shi-rong 《Journal of China University of Mining and Technology》 2007年第3期363-367,共5页
Three different nitrogen ion doses were implanted into a Ti6A14V alloy to improve its mechanical surface properties for the application of artificial joints. The titanium nitride phase and nitrogen element distributio... Three different nitrogen ion doses were implanted into a Ti6A14V alloy to improve its mechanical surface properties for the application of artificial joints. The titanium nitride phase and nitrogen element distribution profile were characterized with X-ray photoelectron spectroscopy (XPS). Nano-indentation tests were carried out on the surface of the Ti6A14V alloy and implanted samples on a large scale of applied loads. The XPS analysis results indicate that nitrogen diffuses into the titanium alloy and forms a hard TiN layer on the Ti6A14V alloy. The nanohardness results reveal that nitrogen ion implantation effectively enhances the surface hardness of Ti6A14V. In addition, the nanohardness clearly reveals load dependence over a large segment of the applied loads. Thus a concept of nanohardness fractal dimension is first proposed and the dual fractal model can effectively describe nonlinear deformation in indentation areas on the Ti6A14V surface. The fractal dimension shows a decreased trend in two regions of applied loads, indicating a decrease of the self-similarity complexity in surface indentation owing to an increase in nanohardness after nitrogen ion implantation. 展开更多
关键词 nanohardness nano-indentation ion implantation
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Influence of heat treatment on microstructure and nanohardness of TiAl alloy solidified under high pressure
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作者 Dong-dong Zhu Duo Dong +4 位作者 Jie-ren Yang Li Liu Xiao-hong Wang Yuan-xiang Zhang Zun-jie Wei 《China Foundry》 SCIE CAS 2020年第6期435-440,共6页
The Ti-48at.%Al alloy solidified under different pressures was prepared using a tungsten-carbide six-anvil apparatus and then heat treated at different temperatures.The effect of heat treatment on microstructure and m... The Ti-48at.%Al alloy solidified under different pressures was prepared using a tungsten-carbide six-anvil apparatus and then heat treated at different temperatures.The effect of heat treatment on microstructure and mechanical properties of high pressure solidified Ti-48Al alloy was investigated.The results showed that the phase constitution of the Ti-48Al alloy solidified under high pressure did not change after heat treatment.After 1,100℃/12 h AC(air cooling),the value of c/a showed a slight increase.The Widmanst?tten structure was formed in the samples solidified under 2 GPa and 4 GPa.More defects were found in the high-pressure samples.The volume fraction ofα2 particles increased with an increase in pressure.After 1,150℃/4 h AC,the discontinuous coarsening phenomenon could only be found in the 4 GPa solidified samples.The formation ofα2 phase can lead to the increase of nanohardness.Compared with the samples before heat treatment,the nanohardness increased about 1.0-1.2 GPa. 展开更多
关键词 heat treatment TIAL MICROSTRUCTURE nanohardness
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Conversion between Vickers hardness and nanohardness by correcting projected area with sink-in and pile-up effects
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作者 Youping LU Yue SU +4 位作者 Wei GE Tengfei YANG Zhanfeng YAN Yugang WANG Songqin XIA 《Plasma Science and Technology》 SCIE EI CAS CSCD 2020年第6期188-199,共12页
The Vickers hardness test has been widely used for neutron-irradiated materials and nanoindentation for ion-irradiated materials.Comparing the Vickers hardness and nanohardness of the same materials quantitatively and... The Vickers hardness test has been widely used for neutron-irradiated materials and nanoindentation for ion-irradiated materials.Comparing the Vickers hardness and nanohardness of the same materials quantitatively and establishing a correlation between them is meaningful.In this study,five representative materials—pure titanium(Ti),nickel(Ni),tungsten(W),304 coarse-grained stainless steel(CG-SS)and 304 nanocrystalline austenitic stainless steel(NG-SS)—are investigated for comparison.The results show that the relationship between Vickers hardness and nanohardness does not conform to a mathematical geometric relationship because of sink-in and pile-up effects confirmed by finite element analysis(FEA)and the results of optical microscopy.Finally,one new method was developed by excluding the effects of sink-in and pile-up in materials.With this improved correction in the projected area of the Vickers hardness and nanohardness,the two kinds of hardness become identical. 展开更多
关键词 Vickers hardness nanohardness CONVERSION
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Corrosion performance and tribological behavior of diamond-like carbon based coating applied on Ni−Al−bronze alloy 被引量:6
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作者 Seyed Elias MOUSAVI Nastaran NAGHSHEHKESH +2 位作者 Mohabbat AMIRNEJAD Hossein SHAMMAKHI Ali SONBOLI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第2期499-511,共13页
The effect of diamond-like carbon(DLC)coating(fabricated by cathodic arc deposition)on mechanical properties,tribological behavior and corrosion performance of the Ni−Al−bronze(NAB)alloy was investigated.Nano-hardness... The effect of diamond-like carbon(DLC)coating(fabricated by cathodic arc deposition)on mechanical properties,tribological behavior and corrosion performance of the Ni−Al−bronze(NAB)alloy was investigated.Nano-hardness and pin-on-plate test showed that DLC coating had a greater hardness compared with NAB alloy.Besides,the decrease in friction coefficient from 0.2 for NAB substrate to 0.13 for the DLC-coated sample was observed.Potentiodynamic polarization and EIS results showed that the corrosion current density decreased from 2.5μA/cm2 for bare NAB alloy to 0.14μA/cm2 for DLC-coated sample in 3.5 wt.%NaCl solution.Moreover,the charge transfer resistance at the substrate−electrolyte interface increased from 3.3 kΩ·cm2 for NAB alloy to 120.8 kΩ·cm2 for DLC-coated alloy,which indicated an increase in corrosion resistance due to the DLC coating. 展开更多
关键词 diamond-like carbon coating Ni−Al−bronze alloy tribological behavior corrosion resistance nanohardness microstructure
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Tribological behavior of AISI302 austenitic stainless steel modified by elevated temperature nitrogen plasma immersion ion implantation 被引量:1
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作者 JIANG Shao-qun MA Xin-xin SUN Yue 《中国有色金属学会会刊:英文版》 CSCD 2004年第z1期301-304,共4页
AISI302 stainless steel samples were modified by elevated temperature nitrogen plasma immersion ion implantation at temperature ranging from 330 ℃ to 450 ℃. The tribological behaviors of the implanted layers of the ... AISI302 stainless steel samples were modified by elevated temperature nitrogen plasma immersion ion implantation at temperature ranging from 330 ℃ to 450 ℃. The tribological behaviors of the implanted layers of the samples were investigated. The samples were characterized by Auger electron spectroscopy (AES), glancing angle X-ray diffraction (GXRD), and nanoindentation. The results show that the implantation temperature plays an important rule on the microstructure and surface properties of the implanted layers. The thickness of the modified layer implanted at 390 ℃ is about 9 μm. It is improved about two orders compared with that of the implanted at room temperature. The surface nanohardness and the wear resistance of elevated temperature implanted layers increase significantly, and the friction coefficient decreases obviously in comparison with the unimplanted one. These data suggests that the improvement results from the formation of new phases such as ε-(Fe, Cr, Ni)2+xN, or noncrystal phase. 展开更多
关键词 AUSTENITE STAINLESS steel ELEVATED temperature plasma immersion ion implantation TRIBOLOGY nanohardness
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Preparation of Al-Cu-Fe-(Sn,Si) quasicrystalline bulks by laser multilayer cladding
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作者 Li-ping Feng Eric Fleury Guo-sheng Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2012年第5期434-440,共7页
(A165Cu20Fe15)100-xSnx (x=0, 12, 20, 30) and A157SitoCulsFe15 powders were cladded on a medium carbon steel (45# steel) substrate by laser multilayer cladding, respectively. The phases and properties of the prod... (A165Cu20Fe15)100-xSnx (x=0, 12, 20, 30) and A157SitoCulsFe15 powders were cladded on a medium carbon steel (45# steel) substrate by laser multilayer cladding, respectively. The phases and properties of the produced quasicrystalline bulks were investigated. It was found that the main phases in the A165Cu2oFe15 sample were crystalline L-Al13Fe4 and icosahedral quasicrystal together with a small volume fraction of 0-A12Cu phase. The volume fraction of icosahedral phase decreased as the Sn content in the (A165Cu20Fe18)100-xSnx samples increased owing to the formation of β-CuSn phase. The increase of Sn content improved the brittleness of the quasicrystal samples. The morphology of the solidification microstructure in the Al57Si10Cu18Fe15 sample changed from elongated shape to spherical shape due to the addition of Si. The nanohardness of the laser multilayer cladded quasicrystal samples was equal to that of the as-cast sample prepared by vacuum quenching. In terms of hardness, the laser cladded A157Si10Cu18Fe15 quasicrystalline alloy has the highest value among all the investigated samples. 展开更多
关键词 QUASICRYSTALS laser cladding phase composition morphology mechanical properties nanohardness
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Microstructure and Mechanical Properties of CrN Films Deposited by Inductively Coupled Plasma Enhanced Radio Frequency Magnetron Sputtering
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作者 刘峰 孟月东 +1 位作者 任兆杏 舒兴胜 《Plasma Science and Technology》 SCIE EI CAS CSCD 2008年第3期340-343,共4页
CrN films have been synthesized on Si(100) wafer by inductively coupled plasma (ICP)-enhanced radio frequency (RF) magnetron sputtering. The effects of ICP power on microstructure, crystal orientation, nanohardn... CrN films have been synthesized on Si(100) wafer by inductively coupled plasma (ICP)-enhanced radio frequency (RF) magnetron sputtering. The effects of ICP power on microstructure, crystal orientation, nanohardness and stress of the CrN films have been investigated. With the increase of ICP power, the current density at substrate increases and the films exhibit denser structure, while the DC self-bias of target and the deposition rate of films decrease. The films change from crystal structure to amorphous structure with the increase of ICP power. The measured nanohardness and the compressive stress of films reach the topmost at ICP power of 150 W and 200 W, respectively. The mechanical properties of films show strong dependence on the crystalline structure and the density influenced by the ICP power. 展开更多
关键词 inductively coupled plasma (ICP) RF magnetron sputtering CRN MICROSTRUCTURE nanohardness STRESS
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Hardness of Mn_2V_2O_7 thin films and its influential factors
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作者 I. Aft in Kariper 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2015年第9期987-991,共5页
Mn2V2O7 thin films were deposited onto amorphous glass substrates using a chemical bath deposition method and different deposition time. X-ray diffraction (XRD) analysis was used to define the structure of the films... Mn2V2O7 thin films were deposited onto amorphous glass substrates using a chemical bath deposition method and different deposition time. X-ray diffraction (XRD) analysis was used to define the structure of the films. Their roughness, thickness, and surface properties were evaluated through atomic force microscopy (AFM). The hardness of the films was measured using a nanohardness tester The film thickness, average grain size, and roughness were positively correlated with each other. These three parameters were observed to increase with the deposition time. The film thickness and average grain size were inversely correlated with the hardness and rough- ness. In addition, the number of crystallites per unit area and the dislocation density were observed to be positively correlated with the hardness and roughness. This study was designed to elucidate and formalize the underlying reasons for these relationships. 展开更多
关键词 manganese vanadate thin films nanohardness influencing factors
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Enhancement of Elastic Modulus of Epoxy Resin with Carbon Nanotubes
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作者 Vijay Kumar Srivastava 《World Journal of Nano Science and Engineering》 2011年第1期1-6,共6页
Nanocomposites consisting of multiwall carbon nanotubes (MWCNT) and epoxy resin were produced by a standard calendaring technique. In this study, 3% multiwall carbon nanotube particles were dispersed in epoxy resin by... Nanocomposites consisting of multiwall carbon nanotubes (MWCNT) and epoxy resin were produced by a standard calendaring technique. In this study, 3% multiwall carbon nanotube particles were dispersed in epoxy resin by weight to produce the multiwall carbon nanotubes/epoxy composite. Nanohardness and Raman spectroscopy tests were used to obtain the modulus of elasticity and Raman intensity of MWCNTs/ epoxy resin composite. The results show that the Raman intensity increased with the increase of Raman shift and Raman intensity also affected with the reinforcement of multiwall carbon nanotubes and 1% exposure of laser power. Also, nanohardness increased with increase of modulus of elasticity, which indicated that the toughness of epoxy resin improved with the addition of multiwall carbon nanotubes. 展开更多
关键词 EPOXY RESIN Multiwall Carbon NANOTUBES nanohardness Raman Spectroscopy MODULUS of ELASTICITY
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Changing of Defect’s Structure and Properties of Superhard Nanostructured Ti-Si-N Coatings, Fabricated Using CPVD, before and after Annealing
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作者 Alexander D. Pogrebnjak Oleksandr V. Bondar +1 位作者 Oleg V. Sobol Vyacheslav M. Beresnev 《Soft Nanoscience Letters》 2013年第3期46-51,共6页
Using such unique methods of analysis as slow positron beam (SPB), RBS, μ-PIXE (proton microbeam), XRD, SEM with EDS, XPS, nanohardness and elastic modulus measurements, we studied superhard nanostructure Ti-Si-N coa... Using such unique methods of analysis as slow positron beam (SPB), RBS, μ-PIXE (proton microbeam), XRD, SEM with EDS, XPS, nanohardness and elastic modulus measurements, we studied superhard nanostructure Ti-Si-N coatings, which were deposited using Cathodic-PVD method, before and after annealing at the temperature of 600°C for 30 minutes. It is shown in the paper that redistribution of N and Si occurs on the borders of nanograins after annealing, amorphous phase α-SiNx (Si3N4) is created, defects segregates on interfaces and forms vacancy-type clusters with rather high concentration from 5 × 1016 cm-3 to 7.5 × 1017 cm-3 due to thermodiffusion. Solid solution (Ti,Si)N and small concentration of α-SiN (close to XRD detection limits) are formed in the coating. Also it was obtained, that deflected mode is formed in the coating (compressive deformation equals to –2.6%), but after thermal annealing deformation reduces to a value of -2.3%. Size of nanograins of solid solution (Ti, Si)N increases from 12.5 nm to (13.2 ÷ 13.4) nm. 25 nm size grains increase their size to 28.5 nm after annealing (under another deposition regime). 展开更多
关键词 NANOSTRUCTURE Wear nanohardness Profiles of DEFECTS TI-SI-N
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Multi-scale analyses of phase transformation mechanisms and hardness in linear friction welded Ti17(a+β)/Ti17(β)dissimilar titanium alloy joint 被引量:3
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作者 Zhenguo GUO Tiejun MA +3 位作者 Xiawei YANG Ju LI Wenya LI Achilles VAIRIS 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第1期312-324,共13页
The Ti17(a+β)-Ti17(β)dual alloy-dual property blisk produced using Linear Friction Welding(LFW)is considered as high-performance component in advanced aeroengine.However,up to now,microstructure evolution and relati... The Ti17(a+β)-Ti17(β)dual alloy-dual property blisk produced using Linear Friction Welding(LFW)is considered as high-performance component in advanced aeroengine.However,up to now,microstructure evolution and relationship between microstructure and micro mechanical properties of LFWed Ti17(a+β)/Ti17(β)dissimilar joint have not been thoroughly revealed.In this work,complex analyses of the phase transformation mechanisms of the joint are conducted,and phase transformations in individual zones are correlated to their microhardness and nanohardness.Results reveal that a dissolution occurs under high temperatures encountered during LFW,which reduces microhardness of the joint to that of Ti17(a+β)and Ti17(β).In ThermoMechanically Affected Zone of Ti17(a+β)(TMAZ-(a+β))side joint,a large number of nanocrystalline a phases form with different orientations.This microstructure strengthens significantly by fine grains which balances partial softening effect of a dissolution,and increases nanohardness of a phase and microhardness of TMAZ-(a+β).Superlattice metastableβphase precipitates from metastableβin Weld Zone(WZ)during quick cooling following welding,because of short-range diffusion migration of solute atoms,especiallyβstabilizing elements Mo and Cr.The precipitation of the superlattice metastableβphase results in precipitation strengthening,which in turn increases nanohardness of metastableβand microhardness in WZ. 展开更多
关键词 Linear friction welding Ti17 titanium alloy Phase transformation MICROHARDNESS nanohardness
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Microstructure and mechanical properties of Ti44Al6Nb1Cr2V alloy after gaseous hydrogen charging at 1373-1693 K 被引量:1
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作者 Teng-Fei Ma Rui-Run Chen +4 位作者 De-Shuang Zheng Jing-Jie Guo Hong-Sheng Ding Yan-Qing Su Heng-Zhi Fu 《Rare Metals》 SCIE EI CAS CSCD 2023年第2期664-671,共8页
The hydrogenation behavior of Ti44A16Nb1Cr2V(at%)alloy at temperature range of 1373-1693 K and its effect on microstructure and room-temperature mechanical properties were studied systematically in this study.The resu... The hydrogenation behavior of Ti44A16Nb1Cr2V(at%)alloy at temperature range of 1373-1693 K and its effect on microstructure and room-temperature mechanical properties were studied systematically in this study.The results show that hydrogen content increases with the increase in temperature,and the maximum hydrogen content is 0.126 wt%at 1693 K.The heat of solution of hydrogen is calculated as 82.9 kJ·mol^(-1)by curve fitting,indicating that hydrogen absorptionin TiAl alloys is endothermic.Hydrogen promotes the lamellar colony size because hydrogen promotes the diffusion of elements.Hydrogen stabilizes B2phase during hydrogenation resulting in more residual B2phase in the hydrogenated alloy.The nanohardness and elastic modulus decrease after hydrogenation due to that hydrogen weakens the bonds.The Ti44A16Nb1Cr2V alloy exhibits higher plasticity and lower flow stress hydrogenation with 0.039 wt%H,and the ultimate compressive strength decreases from 1220 to 1130 MPa,while the fracture strain is enhanced by 26%. 展开更多
关键词 TiAl alloys HYDROGENATION Hydrogen content nanohardness Compressive property
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Effect of Austempering Route on Microstructural Characterization of Nanobainitic Steel 被引量:3
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作者 Huifang Lan Linxiu Du +1 位作者 Na Zhou Xianghua Liu 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2014年第1期19-26,共8页
A low-temperature nanobainitic steel was obtained through one-step and two-step austempering. The effect of austempering temperature, time, and route on bainitic lath width, volume fraction of retained austenite, carb... A low-temperature nanobainitic steel was obtained through one-step and two-step austempering. The effect of austempering temperature, time, and route on bainitic lath width, volume fraction of retained austenite, carbon concen- tration in retained austenite, and nanohardness of bainitic lath and retained austenite was studied. Results showed that the transformation kinetics was slowed down and the bainitic lath was refined as the austempering temperature decreased from 300 to 250 C. Both coarser and finer bainitic laths were obtained with the two-step austempering, which was consistent with the lath size at 300 and 250 C austempering, respectively. X-ray diffraction analysis showed that both volume fraction of retained austenite and its carbon concentration decreased with the decrease of austempering temperature for the one-step austempering, and especially the carbon concentration is obviously increased when the two-step austempering is adopted. The nanohardness of the bainitic lath in the sample after two-step austempering treated lies between that of the samples after 300 and 250 C austempering treated. The product of tensile strength and total elongation of the two-step austempered sample is the highest, which increases monotonously with the product of retained austenite fraction and its carbon concentration. Higher strengthluctility balance may be resulted by the fine bainitic lath, high volume fraction, and high stability of retained austenite in the sample after two-step austempered. 展开更多
关键词 Nanobainitic steel Stability Retained austenite nanohardness Strength-ductility balance
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Effects of rolling deformation on microstructure and hardness of Ti-45Al-9Nb-0.3Y alloy 被引量:1
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作者 张树志 张长江 +2 位作者 侯赵平 孔凡涛 陈玉勇 《Journal of Rare Earths》 SCIE EI CAS CSCD 2016年第2期197-202,共6页
The microstructure evolution of as-rolled Ti-45Al-9Nb-0.3Y alloy as well as the nanohardness ofβ/B2 matrix was investigated by means of scanning electron microscopy (SEM) in backscattered electron mode (BSE) mode, tr... The microstructure evolution of as-rolled Ti-45Al-9Nb-0.3Y alloy as well as the nanohardness ofβ/B2 matrix was investigated by means of scanning electron microscopy (SEM) in backscattered electron mode (BSE) mode, transmission electron microscopy (TEM) and nanoindentation. This high Nb containing TiAl based alloy was rolled with 50%, 60%, 65% reduction, respectively. Omega phase precipitated in B2 phase with an orientation relationship of {110}β//{1120}ω and <111>β//<0001>ω. Moreover, with the increase of de-formation reduction, rod-like structure which was formed inγ grain transformed from (α2+γ) lamellae structure intoα2 phase only. Addi-tionally, nanoinentation experiment revealed that the precipitation hardening ofω phase increased the hardness ofβ/B2 phase. 展开更多
关键词 high Nb containing TiAl based alloy TNB alloy hot rolling omega phase phase transformation nanohardness rare earths
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Analyzing the Effects of Milling and Sintering Parameters on Crystalline Phase Evolution and Mechanical Properties of Al_(86)Ni_(8)Y_(6) and Al_(86)Ni_(6)Y_(4.5)Co_(2)La_(1.5) Amorphous Ribbons
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作者 Ashutosh Sahu Ram Sajeevan Maurya +1 位作者 Lavish Kumar Singh Tapas Laha 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2022年第6期1043-1054,共12页
In the present study,Al_(86)Ni_(8)Y_(6) and Al_(86)Ni_(6)Y_(4.5)Co_(2)La_(1.5) bulk amorphous nanocomposites were synthesized by spark plasma sintering of milled melt spun ribbon particles.The as-cast ribbons were of ... In the present study,Al_(86)Ni_(8)Y_(6) and Al_(86)Ni_(6)Y_(4.5)Co_(2)La_(1.5) bulk amorphous nanocomposites were synthesized by spark plasma sintering of milled melt spun ribbon particles.The as-cast ribbons were of near amorphous nature with minute amount of FCC Al embedded in the amorphous matrix.Milling of the ribbons resulted in partial devitrifi cation due to mechanical crystallization.The milled ribbon particles were sintered in the temperature and pressure range of 300-500℃ and 500-700 MPa,respectively.It was observed that nominal amount of amorphous phase was retained at 500℃ and 500 MPa.With increase in sintering pressure and decrease in sintering temperature,the amount of crystalline phase evolution decreased,and maximum amount of amorphous phase was retained at 300℃ and 700 MPa.The microstructure consisting of amorphous phase embedded with hard intermetallic phases led to increase in the nanohardness of Al_(86)Ni_(8)Y_(6) and Al_(86)Ni_(6)Y_(4.5)Co_(2)La_(1.5) as-cast ribbons from 3.26±0.59 GPa and 3.81±0.58 GPa to 6.06±0.70 GPa and 6.14±0.82 GPa,respectively,for the corresponding consolidated amorphous nanocomposite.Microhardness of the three and five component system bulk samples was 4.19±0.13GPa and 3.6±0.13 GPa,respectively. 展开更多
关键词 Amorphous alloy Milled ribbon Spark plasma Sintering nanohardness Internetallic compound
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