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science China(Technological sciences) 2005年第5期48卷 510-520页

作者： SU Juanhua1,2. LIU Ping2. DONG Qiming2.& LI Hejun1 1. college of materials{2. and engineering, Northwestern Polytechnical university, Xi’an 710072. China 2. college of materials science and engineering, henan university of science and technology, luoyang 471003, China college of materials{2. and engineering Northwestern Polytechnical University Xi’an China college of materials{2. and engineering Henan University of Science and Technology Luoyang China

The thermomechanical treatment process is effective in enhancing the properties of the lead frame copper alloy. In this study, an optimal pattern of the thermomechanical processes for Cu-Cr-Zr was investegated using an intelligent control technique consisting of neural networks and genetic algorithms. The input parameters of the artificial neural network (ANN) are the reduction ratio of cold rolling, aging temperature and aging time. The outputs of the ANN model are the two most important properties of hardness and conductivity. Based on the successfully trained ANN model, genetic algorithms (GA) are used to optimize the input parameters of the model and select perfect combinations of thermomechanical processing parameters and properties. The good generalization performance and optimized results of the integrated model are achieved.

关键词： Cu-Cr-Zr alloy, thermomechanical processing optimization, artificial neural network, genetic algorithms.

Effect of rare-earth element Sm on the corrosion behavior of Mg-6Al-1.2.-0.9Nd alloy

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Rare Metals 2010年第6期29卷 557-560页

作者： LI Quan’an,LI Xiaofeng,ZHANG Qing,and CHEN Jun School of materials science and{2.,henan university of science and technology,luoyang 471003,China School of materials science and{2. Henan University of Science and Technology Luoyang China

The effect of Sm（0 wt.%-2.wt.%） addition on the corrosion behavior of Mg-6Al-1.2.-0.9Nd alloy in 3.5 wt.% NaCl solution has been studied by static corrosion tests,corrosion morphology observation,corrosion scale and microstructure *** results show that,with the increasing of Sm content,the corrosion rate of the alloy decreases at first,then increases and reaches the valley at 0.5 wt.% *** reason is that the proper content of Sm addition can refine the precipitates and make the component and microstructure uniform,and therefore,it remarkably improves the corrosion resistance of the alloy.

关键词： magnesium alloys samarium corrosion behavior microstructure

Melt-spun Al_(70-X)Si_(30)Mn_X (X=0,3,5,7,10) anode in lithium-ion batteries

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science China(Technological sciences) 2009年第8期52卷 2288-2294页

作者： SUN ZhanBo1, LI XuePeng1, WANG XiaoDong1, HU Qing1, ZHAO MingShu1, ZHU YaoMin2. LI Yan2.& SONG XiaoPing1 1 School of science, State Key Laboratory for Mechanical Behavior of materials, Xi’an Jiaotong{2., Xi’an 710049, China 2.School of materials science and engineering, henan university of science and technology, luoyang 471003, China School of science State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong University Xi’an China School of materials science and{2. Henan University of Science and Technology Luoyang China

Al70-XSi30MnX (X=0, 3, 5, 7, 10, mol%) ribbons were prepared by melt spinning. A supersaturated solid solution of Si and Mn in fcc Al and some microstructures consisting of nano grains were obtained. Some alloys with nano-sized grains exhibited high discharge capacities and favorable cycle properties. The capacity of more than 400 mAh/g could be obtained in melt-spun Al67Si30Mn3 alloy after 2. cycles and more than 300 mAh/g after 40 cycles. Li/Si and Li/Al compounds in the anodes of pure Al and pure Si were not detected in Al-Si-Mn alloys inserted by Li. It is considered that the formation of the supersaturated solid solution and refinement of microstructures have prevented the alloys from the forming the compounds with superfluous Li. As a result, the electrochemical properties have been improved.

关键词： Al-Si-Mn alloy melt spinning microstructure electrochemical property

Preparation of Core-shell Cu-Ag Bimetallic Powder via Electroless Coating

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Journal of Wuhan university of technology({2. science) 2009年第4期24卷 637-639页

作者：徐锐 college of Metallurgy science and{2. Central South University college of Chemical and Pharmaceutical engineering Henan Universityof Science and Technology

A novel method of electroless silver coating on copper powders was reported, in which hydrazine was used as the reducing agent, and had some advantages such was used as inhibiting the substitution reaction and reducing consumption of copper powders. In the processes of sensitization and activation, AgNO3 replaces the conventional PdCl2. which solves the impurity of bath. Oxide film on the surface of copper powders was tested by chemical analysis. Ag element tested by XRD and XRF is in the form of Ago and exists on the surface of copper powders, which acts as catalyzer in reduction reaction. Morphology and composition of the coating were characterized by SEM and XRD respectively.

关键词： core-shell bimetallic powders electroless coating

Effect of Fe Particle on the Surface Peeling in Cu-Fe-P Lead Frame

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Journal of Wuhan university of technology({2. science) 2006年第3期21卷 18-20页

作者：苏娟华 college of materials{2. and engineering Henan University of Science and Technology Luoyang 471003ChinaCollege of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072China

Under the surface peeling of Cu- Fe- P lead frame alloy larger Fe particles were observed by energy dispersive spectroscopy. By using the large strain two-dinension plane strain model and elastic plastic finite element method, the cause for peeling damage of Cu-Fe-P lead frame aUoy was investigated. The results show that when the content of Fe particles is more than 30% at local Fe-rich area the intense stress coacentration in the Fe particle would make the Fe particle broken up. The high equivalent stress mutation and the mismatch of equivalent strain 10% at the two sides of intefrace make it easy to develop the crack and peeling damage on finish rolling. The larger Fe particles in the Cu-Fe-P alloy should be avoided.

关键词： Cu-Fe-P lead frame surface peeling equivalent Stress equivalent strain

Dry Friction Characteristics of Ti-6Al-4V Alloy under High Sliding Velocity

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Journal of Wuhan university of technology({2. science) 2007年第4期22卷 582-585页

作者：邱明 School of Mechatronic engineering Henan University of Science and Technology Theory of Lubrication and Bearing Institute Xi'an Jiaotong UniversityXi'an 710049China

Tribological behaviours of Ti-6Al-4V alloy pins sliding against GCr15 steel discs over a range of contact pressures （0.33-1.33 MPa） and sliding velocities （30-70 m/s） were investigated using a pin-on-disc tribometer under unlubricated conditions. The wear mechanisms and the wear transition were analyzed based on examinations of worn surfaces using SEM, EDS and XRD. When the velocity increases, the friction coefficient and the wear rate of the Ti-6Al-4V alloy show typical transition features, namely, the critical values of sliding velocities for 0.33 and 0.67 MPa are 60 and 40 m/s, respectively. The experimental results reveal that the tribological behaviours of Ti-6Al-4V alloys are controlled by the thermal-mechanical effects, which connects with the friction heat and hard particles of the pairs. A tribolayer containing mainly Ti oxides and V oxides is formed on the worn surface of Ti-6Al-4V alloy.

关键词： Ti alloy dry sliding friction behavior contact temperature wear mechanism

Surface Nanocrystallization of Magnesium Alloy AZ91D by High-Energy Shot Peening

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Journal of Wuhan university of technology({2. science) 2009年第4期24卷 515-519页

作者：张津 School of materials science &{2. University of Science and Technology Beijing college of materials{2. & engineering Chongqing University of Technology

High-energy shot peening （HESP）, a method to produce severe plastic deformation by high velocity flying balls, was applied on die cast magnesium alloy AZ91D. Effects of surface nanocrystallization by HESP and heat treatment at different temperatures were investigated. The mi- crostructure evolution was conducted using X-ray diffraction （XRD） and field emission scanning electronic microscopy （FESEM）. The hardness was measured by microhardness tester. The experimental results show that surface nanocrystrallization of AZ91D obtained by HESP would lead to the increase of microhardness. Low temperature heated at 100℃ for 1 h do not change the property obviously. However, both the microstructure and microhardness vary greatly after heat treatment at 400℃ for 1 h.

关键词： AZ91 D surface nanocrystallization HESP microhardnss corrosion resistance

Magnetron sputtering synthesis of large area well-ordered boron nanowire arrays

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science China(Physics,Mechanics & Astronomy) 2004年第4期47卷 403-415页

作者： CAO Limin1,2. ZHANG Ze2.& WANG Wenkui1,2.1. Key Laboratory of Metastable materials science and{2. and college of materials science and engineering, Yanshan university, Qinhuangdao 066004, China 2. Institute of Physics, Chinese Academy of sciences, Beijing 100080, China Key Laboratory of Metastable materials science and{2. and college of materials science and engineering Yanshan University Qinhuangdao China Institute of Physics Chinese Academy of Sciences Beijing China

One-dimensionally nanostructured materials, such as nanowires and nanotubes, are the smallest dimensional structures for efficient transport of electrons and excitons, and are therefore critical building blocks for nanoscale electronic and mechanical devices. In this paper, boron nanowires with uniform diameters from 2. to 80 nm were synthesized by radio-frequency magnetron sputtering of pure boron powder and B2.3 powder mixtures in argon atmosphere. The boron nanowires produced stand vertically on the substrate surface to form well-ordered arrays over large areas with self- organized arrangements without involvement of any template and patterned catalyst. The high-density boron nanowires are parallel to each other and well distributed, forming highly ordered and uniform arrays. A more interesting and unique feature of the boron nanowires is that most of their tips are flat rather than hemispherical in morphologies. Detailed studies on its structure and composition indicate that boron nanowires are amorphous. Boron nanowire appears as a new member in the family of one-dimensional nanostructures. Considering the unique properties of boron-rich solids and other nanostructures, it is reasonable to expect that the boron nanowires will display some exceptional and interesting properties. A vapor-cluster-solid (VCS) mechanism was proposed to explain the growth of boron nanowires based on our experimental observations.

关键词： boron nanowires, magnetron sputtering, arrays, self-assembly.

Dynamic damage and stress-strain relations of ultra-high performance cementitious composites subjected to repeated impact

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science China(Technological sciences) 2010年第6期53卷 1520-1525页

作者： LAI JianZhong1 & SUN Wei2.1 Department of materials science and{2.,Nanjing university of science and technology,Nanjing 2.0094,China 2.college of materials science and{2.,Southeast university,Nanjing 2.1189,China Department of materials science and{2. Nanjing University of Science and Technology Nanjing China college of materials{2. and engineering Southeast University Nanjing China

Ultra-high performance cementitious composites (UHPCC) were prepared by replacing 60% of cement with ultra-fine industrial waste *** dynamic damage and compressive stress-strain relations of UHPCC were studied using split Hopkinson pressure bar (SHPB).The damage of UHPCC subjected to repeated impact was measured by the ultrasonic pulse velocity *** show that the dynamic damage of UHPCC increases linearly with impact times and the abilities of repeated impact resistance of UHPCC are improved with increasing fiber volume *** stress waves on impact were recorded and the average stress,strain and strain rate of UHPCC were calculated based on the wave propagation *** effects of strain rate,fibers volume fraction and impact times on the stress-strain relations of UHPCC were *** show that the peak stress and elastic modulus decrease while the strain rate and peak strain increase gradually with increasing impact times.

关键词： ultra-high performance cementitious composites (UHPCC) split Hopkinson pressure bar (SHPB) repeated impact damage stress-strain

Theoretical analysis of alloy multiplying factor by the empirical electron theory of solids and molecules

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science China(Technological sciences) 2007年第6期50卷 807-814页

作者： SONG YuePeng1,2. LIU GuoQuan2. LI ZhiLin3, FENG ChengMing1 1 Mechanical and Electronic engineering college, Shandong Agricultural{2., Tai’an 2.1018, China 2.college of materials science and engineering,{2. of science and technology, Beijing 100083, China 3 college of Material science and engineering, Beijing{2. of Chemical technology, Beijing 10002., China Mechanical and Electronic engineering college Shandong Agricultural University Tai’an China college of materials{2. and engineering University of Science and Technology Beijing China college of Material science and{2. Beijing University of Chemical Technology Beijing China

By introducing the distribution probability of structural units in austenite contain- ing alloying elements and considering its effects on phase transformation, this paper establishes a calculation model of distribution probability of structural units. A new valence electron structure (VES) parameter-transformation effect coefficient of alloying elements (HL), is defined and then studied both theoretically and ex- perimentally. The relationship between the parameter HL and the multiplying factor (the quenching capability factor) of alloying elements is studied. The results indi- cate that the two parameters (HL and the quenching capability factor) have the same variation characteristic and substance feature. Therefore, the multiplying factor virtually expresses the relative quantity of structural units in the alloying elements-containing austenite.

关键词： multiplying factor (the quenching capability factor), empirical electron theory of solids and molecules, transformation effect coefficient of alloying elements, structural units in austenite containing alloying elements