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Effect of Nd content on electrochemical performances of nanocrystalline and amorphous (Mg_(24)Ni_(10)Cu_2)_(100-x)Nd_x(x=0-20) alloys prepared by melt spinning 被引量:10
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作者 张羊换 杨泰 +3 位作者 卜文刚 蔡颖 张国芳 赵栋梁 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第12期3668-3676,共9页
The nanocrystalline and amorphous Mg2Ni-type alloys with a chemical composition of (Mg24Ni10Cu2)100-xNdx (x=0, 5, 10, 15, 20) were fabricated by melt spinning technology. The effects of spinning rate on the struct... The nanocrystalline and amorphous Mg2Ni-type alloys with a chemical composition of (Mg24Ni10Cu2)100-xNdx (x=0, 5, 10, 15, 20) were fabricated by melt spinning technology. The effects of spinning rate on the structure and electrochemical hydrogen storage performance of the alloys were investigated. The as-spun Nd-free alloy displays an entire nanocrystalline structure, whereas the as-spun Nd-added alloys hold a nanocrystalline and amorphous structure, suggesting that the addition of Nd facilitates the glass forming of the Mg2Ni-type alloys. Increasing the spinning rate from 0 to 40 m/s gives rise to the discharge capacity growing from 42.5 to 100.6 mA·h/g for the x=0 alloy and from 86.4 to 452.8 mA·h/g for the x=10 alloy. And the cycle stability (S20) rises from 40.2%to 41.1%for the x=0 alloy and from 53.2%to 89.7%for the x=10 alloy, respectively. 展开更多
关键词 hydrogen storage alloy Mg2Ni-type alloy ND melt spinning structure
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Electrochemical hydrogen storage characteristics of La_(0.75-x) M_xMg_(0.25)Ni_(3.2)Co_(0.2)Al_(0.1)(M=Zr,Pr;x=0,0.1) alloys prepared by melt spinning 被引量:7
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作者 ZHANG Yanghuan YANG Tai +3 位作者 CAI Ying HOU Zhonghui REN Huiping ZHAO Dongliang 《Rare Metals》 SCIE EI CAS CSCD 2012年第5期-,共9页
In order to ameliorate the electrochemical hydrogen storage performances of La-Mg–Ni system A_2B_7-type electrode alloys, the partial substitution of M (M = Zr, Pr) for La was performed. The melt spinning technology ... In order to ameliorate the electrochemical hydrogen storage performances of La-Mg–Ni system A_2B_7-type electrode alloys, the partial substitution of M (M = Zr, Pr) for La was performed. The melt spinning technology was used to fabricate the La_(0.75-x)M_xMg_0.25Ni_3.2Co_0.2Al_0.1 (M = Zr, Pr; x = 0, 0.1) electrode alloys. The influences of the melt spinning and substituting La with M (M = Zr, Pr) on the structures and the electrochemical hydrogen storage characteristics of the alloys were investigated. The analysis of XRD, SEM, and TEM reveals that the as-cast and spun alloys have a multiphase structure composed of two main phases (La, Mg)_2Ni_7 and LaNi_5 as well as a residual phase LaNi_2 . The as-spun (M = Pr) alloy displays an entire nanocrystalline structure, while an amorphous-like structure is detected in the as-spun (M = Zr) alloy, implying that the substitution of Zr for La facilitates the amorphous formation. The electrochemical measurements exhibit that the substitution of Pr for La clearly increases the discharge capacity of the alloys; however, the Zr substitution brings on an adverse impact. Meanwhile, the M (M = Zr, Pr) substitution significantly enhances its cycle stability. The melt spinning exerts an evident effect on the electrochemical performances of the alloys, whose discharge capacity and high rate discharge ability (HRD) first mount up and then fall with the growing spinning rate, whereas their cycle stabilities monotonously augment as the spinning rate increases. 展开更多
关键词 A_2B_7-type electrode alloy element substitution melt spinning electrochemical performance
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Effects of La substitution on microstructure and hydrogen storage properties of Ti−Fe−Mn-based alloy prepared through melt spinning 被引量:6
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作者 Ze-ming YUAN Zhen QI +3 位作者 Ting-ting ZHAI Hong-zhang WANG Hai-yan WANG Yang-huan ZHANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第10期3087-3095,共9页
The as-spun Ti_(1−x)La_(x)Fe_(0.8)Mn_(0.2)(x=0,0.01,0.03,0.06,0.09,molar fraction)alloys were prepared by melt spinning.The effects of La substitution for Ti on the microstructure,hydrogen storage kinetics and thermod... The as-spun Ti_(1−x)La_(x)Fe_(0.8)Mn_(0.2)(x=0,0.01,0.03,0.06,0.09,molar fraction)alloys were prepared by melt spinning.The effects of La substitution for Ti on the microstructure,hydrogen storage kinetics and thermodynamics of TiFe-type Ti−Fe−Mn-based alloy were investigated.The as-spun alloys hold the TiFe single phase,which transforms to TiFeH_(0.06),TiFeH,and TiFeH_(2) hydrides after hydrogenation.La substitution promotes the formation of micro-defects(such as dislocations and grain boundaries)in the alloys,thus facilitating hydrogen diffusion.In addition,the hydrogen storage kinetics properties are improved after introducing La element.With the rise of La content,the hydrogen storage capacity decreases firstly and then increases,but the absolute value of hydriding enthalpy change(|ΔH|)increases firstly and then reduces.When x=0.01,the maximum value of|ΔH|is obtained to be(25.23±0.50)kJ/mol for hydriding,and the alloy has the maximum hydrogen absorption capacity of(1.80±0.04)wt.%under the conditions of 323 K and 3 MPa. 展开更多
关键词 La substitution Ti−Fe−Mn-based alloy melt spinning hydrogen storage kinetics thermodynamics
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Structure and properties of nanostructured Cu-13.2Al-5.1Ni shape memory alloy produced by melt spinning 被引量:2
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作者 M. IZADINIA K. DEHGHAN H.MOHAMADI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第9期2037-2043,共7页
The microstructure and properties of nanostructured Cu-13.2Al-5.1Ni shape memory alloy (SMA) were compared with those of initial coarse structure. The nanostructured Cu-Al-Ni ribbons were produced via rapid solidifi... The microstructure and properties of nanostructured Cu-13.2Al-5.1Ni shape memory alloy (SMA) were compared with those of initial coarse structure. The nanostructured Cu-Al-Ni ribbons were produced via rapid solidification using melt spinning technique. The structure and properties of both nanostructured and coarse-grain specimens were then characterized using XRD, SEM, AFM and DSC techniques. According to the obtained results, the nanostructured ribbons show one way shape memory effect. Besides, the formation of nanoparticles of γ2 (Cu9Al4) and the nanograins results in a significant decrease in the martensite-austenite transformation temperature. The produced nanostructure not only leads to a considerable increase in the recovered deformation but also results in the structure stability when it is subjected to deformation-recovery cycles. 展开更多
关键词 Cu-Al-Ni shape memory alloys melt spinning rapid solidification nanostructure
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Texture Evolution in Nanocomposite Nd_2Fe_(140B/α-Fe Magnets Prepared by Direct Melt Spinning 被引量:1
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作者 王占勇 徐晖 +2 位作者 倪建森 金红明 周邦新 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第S1期298-301,共4页
Texture evolution in nanocomposite Nd_2Fe_ 14B/α-Fe magnets prepared by direct melt spinning was investigated. The free surface and wheel-contacted surface exhibit different texture direction. Modification of composi... Texture evolution in nanocomposite Nd_2Fe_ 14B/α-Fe magnets prepared by direct melt spinning was investigated. The free surface and wheel-contacted surface exhibit different texture direction. Modification of composition not only enhances magnetic properties, but also changes texture direction of the ribbon. Low temperature heat treatment can increase the magnetic properties to some extent, and high temperature annealing decreases the magnetic properties. Both low and high temperature heat treatment have effects on grain orientation, but the difference still exists between the two surfaces of the ribbon. So it is infeasibility to prepare anisotropic Nd_2Fe_ 14B/α-Fe nanocomposite magnets by direct melt spinning. 展开更多
关键词 nanocomposite magnet Nd_2Fe_ 14B/α-Fe melt spinning anisotropic magnets rare earths
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OBTAINING PRECISE CRITICAL DRAW RATIO OF DRAW RESONANCE IN MELT SPINING BY NUMERICAL SIMULATION OF DIFFERENCE EQUATIONS
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作者 Ji-nanCao 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2005年第3期311-318,共8页
Direct difference methods have been used to solve the simultaneous non-linear partial differential equations formelt spinning without recourse to linearisation or perturbation approximation.The stability of each diffe... Direct difference methods have been used to solve the simultaneous non-linear partial differential equations formelt spinning without recourse to linearisation or perturbation approximation.The stability of each difference schemes wasstudied by error analysis using the Taylor series,and by comparison of the results obtained from numerical simulation withthe logical value in melt spinning.It is found that computation with 19 digit long double precision has significantlysimplified the stability problem of difference equations.Using this method,the precise critical draw ratio of draw resonancein an isothermal and uniform tension spinning of Newtonian fluids can be obtained in between 20.218 and 21.219,a figureconsistent with 20.218 which was obtained by a linear perturbation approximation method by Kase and Denn.It thus haspaved the way to computation of full information for unsteady melt spinning processes using the difference method. 展开更多
关键词 Draw resonance melt spinning Newtonian fluid Numerical simulation.
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OBTAINING THE CRITICAL DRAW RATIO OF DRAW RESONANCE IN MELT SPINNING FOR POWER LAW POLYMER FLUIDS
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作者 Jinan Cao 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2007年第5期501-507,共7页
A direct difference method has been developed for Non-Newtonian power law fluids to solve the simultaneous non-linear partial differential equations of melt spinning, and to determine the critical draw ratio for draw ... A direct difference method has been developed for Non-Newtonian power law fluids to solve the simultaneous non-linear partial differential equations of melt spinning, and to determine the critical draw ratio for draw resonance. The results show that for shear thin fluids, the logarithm of the critical draw ratio has a well defined linear relationship with the power index for isothermal and uniform tension melt spinning. When the power index approaches zero, the critical draw ratio points at unity, indicating no melt spinning can be processed stably for such fluids. For shear thick fluids, the critical draw ratio increases in a more rapid way with increasing the power index. 展开更多
关键词 Draw resonance melt spinning Power law fluid Numerical simulation.
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MORPHOLOGY OF MELT SPINNING SUPERSATURATED B2 NiAl
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作者 SUN Baode CHE Xiaozhou +1 位作者 LIN Dongliang ZHOU Yaohe(Department of Materials Engineering,Shanghai Jiaotong University,Shanghai 20030,China)(Department of Materials Science,Shanghai Jiaotong University,Shanghai 200030,China) 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1996年第2期89-93,共5页
The morphology and structure of melt spinning Ni-33.6at% Al doped with B and RE were investigated.The results show that the alloy consists of L10 martensitic grains and L12 Ni3Al at the grain boundaries when it contai... The morphology and structure of melt spinning Ni-33.6at% Al doped with B and RE were investigated.The results show that the alloy consists of L10 martensitic grains and L12 Ni3Al at the grain boundaries when it contains no B and RE.The addition of 0.11-0.31wt% B can suppress the martensitic transformation and Ni3Al separation at the boundaries,and a supersaturated B2 single phase NiAl is obtained.The addition of 0.05wt% RE can eliminate Ni3Al precipitated at the boundaries and get complete martensite,but 0.2-0.8wt% RE addition can suppress the martensitic transformation, and supersaturated B2 single phase NiAl is obtained.The formation mechanism of supersaturated B2 single phase NiAl has been analyzed. 展开更多
关键词 NIAL supersaturate morphologl melt spinning
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Effect of melt spinning on gaseous hydrogen storage characteristics of nanocrystalline and amorphous Nd-added Mg_2Ni-type alloys
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作者 张羊换 袁泽明 +3 位作者 杨泰 祁焱 郭世海 赵栋梁 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第11期2754-2762,共9页
Nanocrystalline and amorphous Mg-Nd-Ni-Cu quaternary alloys with a composition of(Mg_(24)Ni_(10)Cu_2)_(100-x)Nd_x(x=0, 5, 10, 15, 20) were prepared by melt spinning technology and their structures as well as gaseous h... Nanocrystalline and amorphous Mg-Nd-Ni-Cu quaternary alloys with a composition of(Mg_(24)Ni_(10)Cu_2)_(100-x)Nd_x(x=0, 5, 10, 15, 20) were prepared by melt spinning technology and their structures as well as gaseous hydrogen storage characteristics were investigated. The XRD, TEM and SEM linked with EDS detections reveal that the as-spun Nd-free alloy holds an entire nanocrystalline structure but a nanocrystalline and amorphous structure for the as-spun Nd-added alloy, implying that the addition of Nd facilitates the glass forming in the Mg_2Ni-type alloy. Furthermore, the degree of amorphization of the as-spun Nd-added alloy and thermal stability of the amorphous structure clearly increase with the spinning rate rising. The melt spinning ameliorates the hydriding and dehydriding kinetics of the alloys dramatically. Specially, the rising of the spinning rate from 0(the as-cast was defined as the spinning rate of 0 m/s) to 40 m/s brings on the hydrogen absorption saturation ratio(R_5~a)(a ratio of the hydrogen absorption quantity in 5 min to the saturated hydrogen absorption capacity) increasing from 36.9% to 91.5% and the hydrogen desorption ratio(R_(1 0)~d)(a ratio of the hydrogen desorption quantity in 10 min to the saturated hydrogen absorption capacity) rising from 16.4% to 47.7% for the(x=10) alloy, respectively. 展开更多
关键词 Mg2Ni-type alloy Nd addition melt spinning nanocrystalline and amorphous alloy hydrogen storage kinetics
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Evidence of refilled chamber gas pressure enhancing cooling rate during melt spinning of a Zr_(50)Cu_(40)Al_(10) alloy
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作者 Hong-wang Yang Peng Zhang +4 位作者 M.J.Tan Yuan Ge Wan-ping Tian Rui-chun Wang Rong-de Li 《China Foundry》 SCIE CAS 2015年第4期299-304,共6页
The influence of the refilled gas pressure on the glass forming behaviour of one of the best ternary glass forming alloys Zr50Cu40Al10 was studied for the melt spinning process. The amorphicity of as-quenched ribbons ... The influence of the refilled gas pressure on the glass forming behaviour of one of the best ternary glass forming alloys Zr50Cu40Al10 was studied for the melt spinning process. The amorphicity of as-quenched ribbons was characterized by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The refilled chamber atmospheric pressure is crucial to the cooling rate of melt spinning. At high vacuum, at pressure less than 0.0001 atm, fully crystalline fragments are obtained. Monolithic amorphous ribbons were only obtained at a gas pressure of 0.1 atm or higher. The extended contact length between thecribbons and the copper wheel contributes to the high cooling rate of melt spinning. Higher chamber gas pressure leads to more turbulence of liquid metal beneath the nozzle; therefore, lower pressure is preferable at practical melt spinning processes once glass forming conditions are fulfilled. 展开更多
关键词 metallic glass amorphous alloy melt spinning glass forming behaviour
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Effects of melt spinning process parameters and wheel surface quality on production of 6060 aluminum alloy powders and ribbons
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作者 SultanÖZTÜRK Sefa Emre SÜNBÜL KürşatİCİN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第5期1169-1182,共14页
The aim of this study is to investigate the surface quality of the melt spinning wheel, which was changed from smooth type to textured structure, to atomize liquid metal to form powders. The effects of melt spinning p... The aim of this study is to investigate the surface quality of the melt spinning wheel, which was changed from smooth type to textured structure, to atomize liquid metal to form powders. The effects of melt spinning process parameters like wheel speed, gas ejection pressure, molten metal temperature, nozzle–wheel gap and wheel surface quality on the morphological and microstructural features of 6060 aluminum alloy powders and ribbons were investigated. It was observed that ribbon type material was obtained with the smooth wheel and the powder was produced with textured type. The sizes of produced ribbons with smooth surface wheel varied in the range of 30-170 μm in thickness, 4-8 mm in width, and 0.5-1 m in length. The average powder size of the powders manufactured using the textured wheel was in the range of 161-274 μm, depending on the process parameters.Increasing the wheel speed, melt temperature and decreasing gas ejection pressure, nozzle-wheel gap resulted in the decrease of both ribbon thickness and powder size. The microstructures of the powders and ribbons were the equiaxed cellular type, and the average grain sizes diminished with decreasing the ribbon thickness and powder size. The maximum cooling rates were 2.00×10^5 and 1.26×10^4 K/s for the ribbon with thickness of 30 μm and for the powder with size of 87 μm, respectively. 展开更多
关键词 melt spinning method 6060 aluminum alloy process parameters textured wheel
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Structures and electrochemical performances of La_(0.75-x)Zr_xMg_(0.25)Ni_(3.2)Co_(0.2)Al_(0.1) (x=0-0.2) electrode alloys prepared by melt spinning 被引量:1
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作者 张羊换 赵栋梁 +3 位作者 师颜春 祁焱 郭世海 王新林 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第4期607-613,共7页
The La-Mg-Ni system A2B7-type electrode alloys with nominal composition La0.75-xZrxMg0.25Ni3.2Co0.2Al0.1(x=0,0.05, 0.1,0.15,0.2)were prepared by casting and melt-spinning.The influences of melt spinning on the electro... The La-Mg-Ni system A2B7-type electrode alloys with nominal composition La0.75-xZrxMg0.25Ni3.2Co0.2Al0.1(x=0,0.05, 0.1,0.15,0.2)were prepared by casting and melt-spinning.The influences of melt spinning on the electrochemical performances as well as the structures of the alloys were investigated.The results obtained by XRD,SEM and TEM show that the as-cast and spun alloys have a multiphase structure,consisting of two main phases(La,Mg)Ni3 and LaNi5 as well as a residual phase LaNi2.The melt spinning leads to an obvious increase of the LaNi5 phase and a decrease of the(La,Mg)Ni3 phase in the alloys.The results of the electrochemical measurement indicate that the discharge capacity of the alloys(x≤0.1)first increases and then decreases with the increase of spinning rate,whereas for x>0.1,the discharge capacity of the alloys monotonously falls.The melt spinning slightly impairs the activation capability of the alloys,but it significantly enhances the cycle stability of the alloys. 展开更多
关键词 A2B7-type electrode alloy La-Mg-Ni alloy Ni-MH battery melt-spinNING electrochemical performance
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Studies on Melt Spinning of Sheath-Core Bicomponent Fibers: Fundamental Equations on the Dynamics of Melt Spinning
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作者 Yang Chongchang(杨崇倡) +1 位作者 Wang Huaping(王华平) 《Journal of Donghua University(English Edition)》 EI CAS 2001年第2期37-40,共4页
An attempt was made to numerically compute the temperature profile within the melt spinning of sheath core bicomponent fibers by deriving a set of simultaneous partial differential equations. The effects of accelerati... An attempt was made to numerically compute the temperature profile within the melt spinning of sheath core bicomponent fibers by deriving a set of simultaneous partial differential equations. The effects of acceleration, gravity, and air friction on the kinetics of the polymer were included and the upper-convected Maxwell model as the constitutive equation was adopted in this model.The sheath- core bicomponent fibers were partitioned intb a serial of circular cross section and it is assumed that each circular cross section has a temperature gradient while conducting the equation of energy balance. A mathematical model was developed to describe the melt spinning of sheath-core bicomponent fibers. 展开更多
关键词 melt spinning sheath-core bicomponent fibers mathematical model NUMERICAL simulation
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Gaseous and Electrochemical Hydrogen Storage Properties of Nanocrystalline Mg<sub>2</sub>Ni-Type Alloys Prepared by Melt Spinning
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作者 Zhihong Ma Bo Li +3 位作者 Huiping Ren Zhonghui Hou Guofang Zhang Yanghuan Zhang 《Materials Sciences and Applications》 2011年第3期141-150,共10页
A partial substitution of Ni by Cu has been carried out in order to improve the hydrogen storage characteristics of the Mg2Ni-type alloys. The nanocrystalline Mg20Ni10-xCux (x = 0, 1, 2, 3, 4) alloys are synthesized b... A partial substitution of Ni by Cu has been carried out in order to improve the hydrogen storage characteristics of the Mg2Ni-type alloys. The nanocrystalline Mg20Ni10-xCux (x = 0, 1, 2, 3, 4) alloys are synthesized by the melt-spinning technique. The structures of the as-cast and spun alloys have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM). The electrochemical performances were evaluated by an automatic galvanostatic system. The hydrogen absorption and desorption kinetics of the alloys were determined by using an automatically controlled Sieverts apparatus. The results indicate that the substitution of Cu for Ni does not alter the major phase Mg2Ni. The Cu substitution significantly ameliorates the electrochemical hydrogen storage performances of alloys, involving both the discharge capacity and the cycle stability. The hydrogen absorption capacity of alloys has been observed to be first increase and then decrease with an increase in the Cu contents. However, the hydrogen desorption capacity of the alloys exhibit a monotonous growth with an increase in the Cu contents. 展开更多
关键词 Mg2Ni-Type Alloy Cu SUBSTITUTION melt spinNING Hydrogen Storage Property
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Impacts of Melt Spinning and Element Substitution on Electrochemical Characteristics of the La–Mg–Ni-based A<sub>2</sub>B<sub>7</sub>-Type Alloys
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作者 Yang-huan Zhang Hong-wei Shang +3 位作者 Ying Cai Zhong-hui Hou Guo-fang Zhang Dong-liang Zhao 《Advances in Materials Physics and Chemistry》 2012年第4期78-83,共6页
The partial substitution of Zr for La has been performed in order to ameliorate the electrochemical hydrogen storage performances of La–Mg–Ni based A2B7-type electrode alloys. The melt spinning technology was used t... The partial substitution of Zr for La has been performed in order to ameliorate the electrochemical hydrogen storage performances of La–Mg–Ni based A2B7-type electrode alloys. The melt spinning technology was used to prepare the La0.75-xZrxMg0.25Ni3.2Co0.2Al0.1 (x=0, 0.05, 0.1, 0.15, 0.2) electrode alloys. The impacts of the melt spinning and the substituting La with Zr on the structures and the electrochemical hydrogen storage characteristics of the alloys were systemically investigated. The analysis of XRD and TEM reveals that the as-cast and spun alloys have a multiphase structure, composing of two main phases (La, Mg)2Ni7 and LaNi5 as well as a residual phase LaNi2. The electrochemical measurement indicates that both the substitution of Zr for La and the melt spinning ameliorate the electrochemical cycle stability of the alloys dramatically. Furthermore, the high rate discharge ability (HRD) of the as-spun (10 m/s) alloys notably declines with growing the amount of Zr substitution, while it first augments and then falls for the (x=0.1) alloy with rising the spinning rate. 展开更多
关键词 A2B7-Type Alloy Substituting LA with Zr melt-spinNING Electrochemical Characteristics
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Structures and electrochemical performances of RE-Mg-Ni-Mn-based alloys prepared by casting and melt spinning 被引量:7
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作者 张羊换 杨泰 +3 位作者 蔡颖 胡锋 祁焱 赵栋梁 《Journal of Rare Earths》 SCIE EI CAS CSCD 2016年第12期1241-1251,共11页
La-Mg-Ni-Mn-based AB2-type La(1–x)CexMgNi(3.5)Mn(0.5)(x=0–0.4) alloys were prepared by melt spinning technology. The detections of X-ray diffraction(XRD) and scanning electron microscopy(SEM) indicated t... La-Mg-Ni-Mn-based AB2-type La(1–x)CexMgNi(3.5)Mn(0.5)(x=0–0.4) alloys were prepared by melt spinning technology. The detections of X-ray diffraction(XRD) and scanning electron microscopy(SEM) indicated that the experimental alloys consisted of a major phase LaMgNi4 and a secondary phase LaNi5. With spinning rate growing, the abundance of LaMgNi4 phase increased and that of LaNi5 phase decreased. Moreover, with the melt spinning rate increasing, both the lattice constants and cell volumes increased, and further accelerated the grains refinement of the alloys. The electrochemical tests showed that the as-spun alloys possessed excellent capability of activation, achieving the maximum discharge capacities just at the first cycling without any activation needed. As for the as-spun alloys, its discharge potential characteristics could be improved obviously by adopting the technology of melt spinning. In addition, the melt spinning raised electrochemical cycle stability of the alloys, the main reason was that the melt spinning enhanced the anti-pulverization ability of the alloys. With spinning rate increasing, the discharge capacity of the alloys presented a tendency to increase firstly then decrease. Moreover, the electrochemical kinetics of the alloys showed the same trend under fixed condition. 展开更多
关键词 AB2-type alloy Ce substitution for La melt spinning electrochemical performance KINETICS rare earths
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A Comparison Study of Hydrogen Storage Thermodynamics and Kinetics of YMg11Ni Alloy Prepared by Melt Spinning and Ball Milling 被引量:3
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作者 Yang-Huan Zhang Wei Zhang +3 位作者 Jin-Liang Gao Ze-Ming Yuan Wen-Gang Bu Yan Qi 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2017年第11期1040-1048,共9页
Melt spinning (MS) and ball milling (BM) were employed to fabricate YMg11Ni alloy, and their structures and hydrogen storage performances were examined. The results reveal that the as-spun and as-milled alloys bot... Melt spinning (MS) and ball milling (BM) were employed to fabricate YMg11Ni alloy, and their structures and hydrogen storage performances were examined. The results reveal that the as-spun and as-milled alloys both exhibit the nanocrystalline and amorphous structure. The as-milled alloy shows a larger hydrogen absorption capacity as compared with the as-spun alloy. More than that, the as-milled alloy exhibits lower onset hydrogen desorption temperature than the as-spun one, which are 549.8 and 560.9 K, respectively. Additionally, the as-milled alloy shows a superior hydrogen desorption property to the as-spun one. On the basis of the time needed by desorbing hydrogen of 3 wt% H2, for the as- milled alloy, it needs 1106, 456, 343, and 180 s corresponding to hydrogen desorption temperatures of 593, 613, 633, and 653 K. However, for the as-spun alloy, the time needed is greater than 2928, 842, 356, and 197 s corresponding to the same temperatures. Hydrogen desorption activation energies of as-milled and as-spun alloys are 98.01 and 105.49 kJ/mol, respectively, which is responsible for that the as-milled alloy possesses a much faster dehydriding rate. By means of the measurement of pressure-composition-temperature (P-C-T) curves, the dehydrogenation enthalpy change of the alloys prepared by MS (△Hoe(MS)) and BM (△Hdc(BM)) is 81.84 and 79.46 kJ/mol, respectively, viz. △Hde(MS) 〉 △Hoc(BM). 展开更多
关键词 Mg-based alloy Ball milling melt spinning Hydrogen storage kinetics Comparison
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Numerical simulation of single roller melt spinning for NdFeB alloy based on finite element method 被引量:2
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作者 Xu-Chao Wang Ming Yue +2 位作者 Dong-Tao Zhang Wei-Qiang Liu Ming-Gang Zhu 《Rare Metals》 SCIE EI CAS CSCD 2020年第10期1145-1150,共6页
The numerical simulation model of single roller melt spinning for rapid quenching process of NdFeB alloy was built,and the vacuum chamber,cooling roller and sample were taken into account as a system.The existing matu... The numerical simulation model of single roller melt spinning for rapid quenching process of NdFeB alloy was built,and the vacuum chamber,cooling roller and sample were taken into account as a system.The existing mature technology was in order to verify the correctness of simulation.The rapid quenching ribbons with different roll speeds were used as the simulation objects.The results of the numerical simulation and experiments show that the validity of the model has been testified and the reasons of the formation of complete quenching ribbons and by-product have been explained.The experimental thickness of the ribbons is proportional to the theoretical thickness.In the same spray condition,with the roll speed increasing,the thickness decreases linearly.At the speed range of25-30 m·s^(-1),the simulated calculation date is close to the experimental date,which can be considered as an ideal technological parameter. 展开更多
关键词 NDFEB melt spinning Finite element method Numerical simulation
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Preparation and Magnetic Properties of Melt-Spinning Nd_2Fe_(14)B/α-Fe Nanocomposite Magnets 被引量:1
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作者 王伟 倪建森 +3 位作者 徐晖 周邦新 李强 王占勇 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第4期505-508,共4页
Nd_(11)Fe_(71)Co_8V_(1.5)Cr_1B_(7.5) magnet was prepared by melt-spinning and subsequently annealed. The effects of the wheel speed on the magnetic properties and microstructure were studied. The results reveal that f... Nd_(11)Fe_(71)Co_8V_(1.5)Cr_1B_(7.5) magnet was prepared by melt-spinning and subsequently annealed. The effects of the wheel speed on the magnetic properties and microstructure were studied. The results reveal that fine nanocomposite microstructure consisting of Nd_2Fe_(14)B and α-Fe phases can be developed at an optimum wheel speed of about 21 m·s^(-1). After optimal annealing (640 ℃×4 min), magnetic properties of B_r=0.64 T, (()_jH_c)=903.5 kA·m^(-1) and (BH)_(max)=71 (kJ·m^(-3)) were obtained for the bonded magnets. The addition of Cr element significantly reduces grain size, increasing the intrinsic coercivity and maximum magnetic energy product. 展开更多
关键词 nanocomposite magnets melt spinning exchange coupling rare earths
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Highly Improved Gaseous Hydrogen Storage Characteristics of the Nanocrystalline and Amorphous Nd-Cu-added Mg_2Ni-type Alloys by Melt Spinning
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作者 Yanghuan Zhang Tingting Zhai +3 位作者 Baowei Li Huiping Ren Wengang Bu Dongliang Zhao 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2014年第10期1020-1026,共7页
The nanocrystalline and amorphous Mg-Nd-Ni-Cu quaternary alloys with a composition of (Mg24Ni10Cu2)loo-xNdx (x = 0-20) were prepared by melt spinning. The X-ray diffraction and transmission electron microscopy ins... The nanocrystalline and amorphous Mg-Nd-Ni-Cu quaternary alloys with a composition of (Mg24Ni10Cu2)loo-xNdx (x = 0-20) were prepared by melt spinning. The X-ray diffraction and transmission electron microscopy inspections reveal that, by varying the spinning rate and the Nd content, different microstructures could be obtained by melt spinning. Particularly, the as-spun Nd-free alloy holds an entire nanocrystalline structure but the as-spun Nd-added alloy has a nanocrystalline and amorphous structure, which implies that the addition of Nd facilitates the glass forming in the Mg2Ni-type alloy. Also, the degree of the amorphization in the as-spun Nd-added alloys clearly increases with increasing the spinning rate and the Nd content. The H-storage capacity and the hydrogenation kinetics of amorphous, partially and completely nanocrystalline alloys were investigated and it was found that they are dependent on the microstructure and the phase composition of the alloys. Specially, enhancing the spinning rate from 0 (the as-cast was defined as the spinning rate of 0 m/s) to 40 m/s makes the hydrogen absorption saturation ratio (R5a) (a ratio of the hydrogen absorption quantity in 5 min to the saturated hydrogen absorption capacity) increase from 35.2% to 90.3% and the hydrogen desorption ratio (R10d) (a ratio of the hydrogen desorption quantity in 10 min to the saturated hydrogen absorption capacity) rise from 12.7% to 44.9% for the (x = 5) alloy. And the growing of the Nd content from 0 to 20 gives rise to the R5a and R10d values rising from 85.7% to 94.5% and from 36.7% to 54.8% for the as-spun (30 m/s) alloys, respectively. 展开更多
关键词 Mg2Ni-type alloy Nd addition melt spinning STRUCTURES Hydrogen storage
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