研究了60 mm Q345B碳钢/10 mm 304不锈钢复合板坯在1200℃仅加热不轧制及进行2倍压缩比轧制后30 mm Q345/5 mm 304复合界面Cr、Ni的扩散行为。试验结果表明,加热过程中,界面是否贴合并未影响扩散的进行,真空状态下不锈钢侧Cr、Ni发生蒸...研究了60 mm Q345B碳钢/10 mm 304不锈钢复合板坯在1200℃仅加热不轧制及进行2倍压缩比轧制后30 mm Q345/5 mm 304复合界面Cr、Ni的扩散行为。试验结果表明,加热过程中,界面是否贴合并未影响扩散的进行,真空状态下不锈钢侧Cr、Ni发生蒸发逸出不锈钢并向碳钢侧发生了扩散,Cr扩散距离大于Ni。轧制后复合界面建立冶金结合,界面两侧浓度差异驱动Cr、Ni继续向碳钢侧扩散,初始加热扩散区被轧薄,复合界面两侧,Cr浓度差异小,Ni浓度差异大;2倍压缩比轧制后,不锈钢侧仅形成了宽度20μm的贫Cr区及10μm的贫Ni区。展开更多
A nickel-based coating was deposited on the pure Al substrate by immersion plating,and the Al/Cu bimetals were prepared by diffusion bonding in the temperature range of 450-550 ℃.The interce microstructure and fractu...A nickel-based coating was deposited on the pure Al substrate by immersion plating,and the Al/Cu bimetals were prepared by diffusion bonding in the temperature range of 450-550 ℃.The interce microstructure and fracture surface of Al/Cu joints were studied by scanning electron microscopy（SEM） and X-ray diffraction（XRD）.The mechanical properties of the Al/Cu bimetals were measured by tensile shear and microhardness tests.The results show that the Ni interiayer can effectively eliminate the formation of Al-Cu intermetallic compounds.The Al/Ni interface consists of the Al3Ni and Al3Ni2 phases,while it is Ni-Cu solid solution at the Ni/Cu interce.The tensile shear strength of the joints is improved by the addition of Ni interiayer.The joint with Ni interiayer annealed at 500 ℃ exhibits a maximum value of tensile shear strength of 34.7 MPa.展开更多
The effect of high magnetic field on the atomic interdiffusion in Ni-Cu system was studied using the Cu/Ni/Cu diffusion couples. During the atomic interdiffusion in Ni-Cu system, it was found that the interdiffusion c...The effect of high magnetic field on the atomic interdiffusion in Ni-Cu system was studied using the Cu/Ni/Cu diffusion couples. During the atomic interdiffusion in Ni-Cu system, it was found that the interdiffusion coefficients increased with the increase of molar fraction of Ni atoms in the interdiffusion zones when the couples were annealed with or without the magnetic field. It was noted that all corresponding interdiffusion coefficients under the magnetic field are smaller than those without the magnetic field. The results demonstrate that the magnetic field retards the atomic interdiffusion in Ni-Cu system. This retardation is achieved through reducing the frequency factors but not changing the interdiffusion activation energies.展开更多
Spherical Ni（OH）2 particles were prepared by an aqueous solution precipitation route. The structure of spherical Ni（OH）2 was investigated by scanning electron microscopy and transmission electron microscopy and co...Spherical Ni（OH）2 particles were prepared by an aqueous solution precipitation route. The structure of spherical Ni（OH）2 was investigated by scanning electron microscopy and transmission electron microscopy and compared with that of traditional Ni（OH）2. The results show that the spherical nickel hydroxide consists of （Ni（OH）2） spheres with a reticulate structure of platelet-like, which is almost arranged radially and the crystalline grains intervene and connect with each other to form a three-dimensional net. The spherical Ni（OH）2 particle is full of pores, crannies between cleave planes. It is supposed that this structure is beneficial to the structural stability for the spherical particles during the charge/discharge processes and can improve the cycle life of the electrode; the pores and the crannies in spherical particles can shorten the proton diffusion distance and speed its velocity, which may result in that the local polarization is lowered. The electrochemical performances of the spherical Ni（OH）2 are improved by enhancing the conducting properties of the crystalline lattice due to its quick proton diffusion.展开更多
Phase equilibria in Ti?Ni?Pt ternary system have been experimentally determined through diffusion triple technique combined with alloy samples approach.Assisted with electron probe microanalysis(EPMA)and X-ray diffrac...Phase equilibria in Ti?Ni?Pt ternary system have been experimentally determined through diffusion triple technique combined with alloy samples approach.Assisted with electron probe microanalysis(EPMA)and X-ray diffraction(XRD)techniques,isothermal sections at 1073 and 1173 K of this system were constructed and existence of ternary phase Ti2(Ni,Pt)3 was confirmed.In addition,binary compounds Ti3Pt5 and TiPt3-were found to be stable at 1073 and 1173 K,and remarkable ternary solubility in some binary compounds was detected,e.g.,solubility of Pt in TiNi can be up to about 36%(molar fraction)at 1073 K and 40%(molar fraction)at 1173 K.Furthermore,a ternary invariant transition reaction TiNi3+Ti3Pt5→Ti2(Ni,Pt)3+TiPt3+at a temperature between 1073 and 1173 K was deduced.展开更多
FT-IR spectrometry, TPD and adsorption isotherms of thiophene on NaY/NiY zeolites were carried out and the diffusion coefficient was obtained by means of its real-time dynamic curves. The loading of thiophene adsorbed...FT-IR spectrometry, TPD and adsorption isotherms of thiophene on NaY/NiY zeolites were carried out and the diffusion coefficient was obtained by means of its real-time dynamic curves. The loading of thiophene adsorbed on the NaY zeolite decreased with an increasing temperature, which was ascribed to the patterns of physical adsorption. Both physical and chemical adsorption phenomena were detected on the NiY zeolite, with the 0 complexation and S-M interaction existing during the chemical adsorption. The loading of thiophene adsorbed on the NiY zeolite at 302 K and 335 K was equal, but it decreased at 373 K. The diffusion coefficient of thiophene on the NaY zeolite decreased when the loading increased to more than 0.02 mmol/g, and on the contrary that of thiophene on the NiY zeolite did not change obviously with the loading adsorbed.展开更多
Departing from the volume-averaging method,an overall solidification kinetic model for undercooled single-phase solid-solution alloys was developed to study the effect of back diffusion on the solidification kinetics....Departing from the volume-averaging method,an overall solidification kinetic model for undercooled single-phase solid-solution alloys was developed to study the effect of back diffusion on the solidification kinetics.Application to rapid solidification of undercooled Ni-15%Cu（mole fraction） alloy shows that back diffusion effect has significant influence on the solidification ending temperature but possesses almost no effect on the volume fraction solidified during recalescence.Inconsistent with the widely accepted viewpoint of Herlach,solidification ends at a temperature between the predictions of Lever rule and Scheil＇s equation,and the exact value is determined by the effect of back diffusion,the initial undercooling and the cooling rate.展开更多
文摘研究了60 mm Q345B碳钢/10 mm 304不锈钢复合板坯在1200℃仅加热不轧制及进行2倍压缩比轧制后30 mm Q345/5 mm 304复合界面Cr、Ni的扩散行为。试验结果表明,加热过程中,界面是否贴合并未影响扩散的进行,真空状态下不锈钢侧Cr、Ni发生蒸发逸出不锈钢并向碳钢侧发生了扩散,Cr扩散距离大于Ni。轧制后复合界面建立冶金结合,界面两侧浓度差异驱动Cr、Ni继续向碳钢侧扩散,初始加热扩散区被轧薄,复合界面两侧,Cr浓度差异小,Ni浓度差异大;2倍压缩比轧制后,不锈钢侧仅形成了宽度20μm的贫Cr区及10μm的贫Ni区。
基金Projects (51274054,51375070,51271042) supported by the National Natural Science Foundation of ChinaProjects (2013M530913) supported by the China Postdoctoral Science Foundation
文摘A nickel-based coating was deposited on the pure Al substrate by immersion plating,and the Al/Cu bimetals were prepared by diffusion bonding in the temperature range of 450-550 ℃.The interce microstructure and fracture surface of Al/Cu joints were studied by scanning electron microscopy（SEM） and X-ray diffraction（XRD）.The mechanical properties of the Al/Cu bimetals were measured by tensile shear and microhardness tests.The results show that the Ni interiayer can effectively eliminate the formation of Al-Cu intermetallic compounds.The Al/Ni interface consists of the Al3Ni and Al3Ni2 phases,while it is Ni-Cu solid solution at the Ni/Cu interce.The tensile shear strength of the joints is improved by the addition of Ni interiayer.The joint with Ni interiayer annealed at 500 ℃ exhibits a maximum value of tensile shear strength of 34.7 MPa.
基金Project(2011CB012803) supported by the National Basic Research Program of ChinaProject(NCET-10-0278) supported by Program for New Century Excellent Talents in University,China
文摘The effect of high magnetic field on the atomic interdiffusion in Ni-Cu system was studied using the Cu/Ni/Cu diffusion couples. During the atomic interdiffusion in Ni-Cu system, it was found that the interdiffusion coefficients increased with the increase of molar fraction of Ni atoms in the interdiffusion zones when the couples were annealed with or without the magnetic field. It was noted that all corresponding interdiffusion coefficients under the magnetic field are smaller than those without the magnetic field. The results demonstrate that the magnetic field retards the atomic interdiffusion in Ni-Cu system. This retardation is achieved through reducing the frequency factors but not changing the interdiffusion activation energies.
基金Project(50134020) supported by the National Natural Science Foundation of China
文摘Spherical Ni（OH）2 particles were prepared by an aqueous solution precipitation route. The structure of spherical Ni（OH）2 was investigated by scanning electron microscopy and transmission electron microscopy and compared with that of traditional Ni（OH）2. The results show that the spherical nickel hydroxide consists of （Ni（OH）2） spheres with a reticulate structure of platelet-like, which is almost arranged radially and the crystalline grains intervene and connect with each other to form a three-dimensional net. The spherical Ni（OH）2 particle is full of pores, crannies between cleave planes. It is supposed that this structure is beneficial to the structural stability for the spherical particles during the charge/discharge processes and can improve the cycle life of the electrode; the pores and the crannies in spherical particles can shorten the proton diffusion distance and speed its velocity, which may result in that the local polarization is lowered. The electrochemical performances of the spherical Ni（OH）2 are improved by enhancing the conducting properties of the crystalline lattice due to its quick proton diffusion.
基金Project(2016YFB0701404)supported by the National Key Research and Development Program of ChinaProject(51171210)supported by the National Natural Science Foundation of China
文摘Phase equilibria in Ti?Ni?Pt ternary system have been experimentally determined through diffusion triple technique combined with alloy samples approach.Assisted with electron probe microanalysis(EPMA)and X-ray diffraction(XRD)techniques,isothermal sections at 1073 and 1173 K of this system were constructed and existence of ternary phase Ti2(Ni,Pt)3 was confirmed.In addition,binary compounds Ti3Pt5 and TiPt3-were found to be stable at 1073 and 1173 K,and remarkable ternary solubility in some binary compounds was detected,e.g.,solubility of Pt in TiNi can be up to about 36%(molar fraction)at 1073 K and 40%(molar fraction)at 1173 K.Furthermore,a ternary invariant transition reaction TiNi3+Ti3Pt5→Ti2(Ni,Pt)3+TiPt3+at a temperature between 1073 and 1173 K was deduced.
文摘FT-IR spectrometry, TPD and adsorption isotherms of thiophene on NaY/NiY zeolites were carried out and the diffusion coefficient was obtained by means of its real-time dynamic curves. The loading of thiophene adsorbed on the NaY zeolite decreased with an increasing temperature, which was ascribed to the patterns of physical adsorption. Both physical and chemical adsorption phenomena were detected on the NiY zeolite, with the 0 complexation and S-M interaction existing during the chemical adsorption. The loading of thiophene adsorbed on the NiY zeolite at 302 K and 335 K was equal, but it decreased at 373 K. The diffusion coefficient of thiophene on the NaY zeolite decreased when the loading increased to more than 0.02 mmol/g, and on the contrary that of thiophene on the NiY zeolite did not change obviously with the loading adsorbed.
基金Project(2011CB610403) supported by the National Basic Research Program of ChinaProject(51125002) supported by the National Science Fund for Distinguished Young Scholars of China+4 种基金Projects(51101122,51071127,50901059) supported by the National Natural Science Foundation of ChinaProject(111502) supported by the Huo Yingdong Young Teacher Fund,ChinaProjects(66-QP-2010, 24-TZ-2009) supported by the Free Research Fund of State Key Laboratory of Solidification Processing,ChinaProjects(JC201008, JC200801) supported by the Fundamental Research Fund of Northwestern Polytechnical University,ChinaProject(B08040) supported by the Program of Introducing Talents of Discipline to Universities,China
文摘Departing from the volume-averaging method,an overall solidification kinetic model for undercooled single-phase solid-solution alloys was developed to study the effect of back diffusion on the solidification kinetics.Application to rapid solidification of undercooled Ni-15%Cu（mole fraction） alloy shows that back diffusion effect has significant influence on the solidification ending temperature but possesses almost no effect on the volume fraction solidified during recalescence.Inconsistent with the widely accepted viewpoint of Herlach,solidification ends at a temperature between the predictions of Lever rule and Scheil＇s equation,and the exact value is determined by the effect of back diffusion,the initial undercooling and the cooling rate.
