bluuebunny/crossref_metadata_2025 huggingface dataset:
Cooling by the Sine Function to Produced Semi-Solid Aluminum Alloys
Authors: Zhang Song Yang , Guo Xiao Qin , Liu Chang Hong , Li Si Zhong , Zhang Ying
Published: November 2010

There are many advantages of semi-solid processing technology such as energy saving, high efficiency and net-shaped processing. So it is a promising manufacturing technology in 21 century .It is the premise of getting the non-dendrite semisolid slurry to realize the semisolid processing.This paper reviewed the development of the technique of preparation for semi-solid state slurry and introduced some new researchment about the technique of preparation slurry for semi-solid processing. It researched a new technique of preparation for semi-solid state slurry—cooling by the sine function to produced the semi-solid state slurry. The result showed that the aluminum alloy melt was cooled and controlled nucleation and limited growth in the sine wave The fundamental principles through which sound semi-solid slurry can be effectively obtained were summarized.On the basis of the experiment and simulation，it analysised the temperature field and the flow field of the semisolid 2A12 slurry flow through sine passage. The result showed that there is the cooling and the self-stirring when the semisolid 2A12 slurry flow through sine passage. The fundamental principles through which sound semi-solid slurry can be effectively obtained were summarized. Finally, we presented a patent this simple process .
The Effect of Weld Size on Joint Mechanical Properties of 5A90Al-Li Alloy
Authors: Chen Li , Xu Wei Wei , Gong Shui Li
Published: November 2010

The quality of full penetration laser welding 5A90 Al-Li alloy can be evaluated by weld width, especially the ratio of weld back width to weld surface width (Rw), according to the results from laser welding experiment. And Rw will influence the joint properties, such as tensile strength and fatigue. In this paper, the effect of Rw on joint properties of 5A90 Al-Li alloy sheet are discussed, these joint welded by laser welding, dual beam laser welding .
Study on Hydrogen Fluctuations in Aluminum Melt under CAP Process
Authors: Huang Cai Min , Zeng Jian Min
Published: November 2010

Hydrogen is the only gas that is appreciably soluble in aluminum and its alloy. Its solubility is small but the effect is significant on the mechanical properties and finishing characteristics of aluminum alloys. In order to remove hydrogen from the aluminum melt and shape intricate castings, a new process, Casting under Adjusted Pressure (CAP for short), was invented. An interesting hydrogen fluctuation phenomenon has been found in the CAP process. The hydrogen concentration within the molten aluminum changes with cyclic vacuuming-pressurizing programs for CAP process. The experimental results indicate that the relative humidity of compressed air exerts a significant influence on the hydrogen concentration of aluminum melt. The hydrogen concentration is maintained between 0.10 and 0.15 ml/100gAl by using compressed air with relative humidity 80-85%. Under the condition of dry compressed air, the hydrogen concentration can be maintained at a level as low as 0.05-0.08 ml/100gAl, which is beneficial to obtain high air-tightness aluminum alloy castings. In addition, the experiment shows that magnesium concentration has no obvious influences on CAP process.
Stress Distribution Characteristics of Different Laser Welding Joints
Authors: Wu Bing , Gong Shui Li , Chen Li
Published: November 2010

For quantitatively understanding the influences of the welded lap joint forms on the stress concentration, six different forms of overlap joints were designed, and then the stress distribution characteristics of these overlap joints were carried out in this paper. The results show that, the stress concentration of the model (a) and (b) are the highest level; and the stress concentration of the model (c) and (d) are significantly lower; the stress concentration of the model (e) is even lower than that of model (c) and (d); the stress concentration of the model (f) is zero.
Mapping of Phase Compositions and Air-Oxidized Titanium Silicon Carbide (Ti3SiC2)
Authors: Oo Zeya , Low Jim , O’Connor Brian
Published: November 2010

Ternary carbides such as Ti3AlC2 and Ti3SiC2 are nano-layered ceramics with the general formula Mn+1AXn (n=1-3), where M is an early transition metal, A is a group A element, and X is either carbon and/or nitrogen. These ceramics exhibit a unique combination of mechanical, electrical, thermal and physical properties such as good high-temperature strength, and excellent corrosion and damage resistance. For instance, the electrical and thermal conductivities of Ti3SiC2 are greater than that of titanium and its machinability is similar to graphite. However, these ceramics are susceptible to thermal dissociation at ~1400°C in inert environments (e.g., vacuum or argon) to form TiC and Ti5Si3C. The chemistry and kinetics of the dissociation processes involved are not yet fully understood. Surprisingly, the study of thermal stability in ternary carbides has received relatively little attention despite its importance in applications such as heating elements or the feasibility of designing functionally-graded Ti3SiC2-TiC with unique wear resistance and damage tolerance. In this paper, we present the thermochemical processes, phase relations and air-oxidised of Ti3SiC2 from 25-1500°C as revealed by neutron diffraction (ND), secondary-ions mass spectroscopy (SIMS).
The Effect of Mn Addition on Recrystallization of Cold Rolled Al-Mg-Si-Cu Alloy
Authors: Wang You Bin , Lin Yi , Zeng Jian Min
Published: November 2010

Small amounts of Mn have been used in order to modify the microstructure and thus improve the properties of the alloys. The effect of Mn addition on structure and properties of cold rolled Al-Mg-Si-Cu alloy at different annealed temperatures is presented in this paper. Both recrystallization temperature and activation energy of recrystallization are obtained from the hardness-temperature curves. The results show that Mn can have an inhibitive effect on recrystallization. Within a certain concentration of Mn in the alloy (<0.7 wt.%) both the activation energy of recrystallization and recrystallization start temperature increase with the addition of Mn content. The activation energy of recrystallization of the alloy which contains 0 wt.% Mn, 0.3 wt.% Mn and 0.7 wt.% Mn are respectively 134.4 kJ·mol-1, 137.4 kJ·mol-1 and 140.1 kJ·mol-1 and the recrystallization start temperature increases from 190 to 230 as Mn content increases from 0 to 0.7 wt.%.
Precipitation and Recrystallization Behaviors of a High-Nitrogen Austenitic Stainless Steel Aging at 90°C
Authors: Shi Feng , Qi Yang , Xu Ming Zhou , Liu Chun Ming
Published: November 2010

The behaviors of precipitation and recrystallization aging at 900 after cold work in a Fe-18Cr-12Mn-0.48N high-nitrogen austenitic stainless steel were investigated by means of optical microscopy (OM) and transmission electron microscopy (TEM). The results show that precipitation and recrystallization occur simultaneously after aging at 900 for 10min. The precipitates firstly appear at dislocation, sub-boundary and inside the subgrain. Precipitation at these positions hinders the formation of recrystallization nucleus. With aging time increasing, precipitates appear in the recrystallized grain boundary and inside the grain. Precipitation at these positions hinders the growth of the recrystalized grains.
Influence of [Si], [Ti] Content on Fluidity of Hot Metal
Authors: He Yuan Yuan , Liu Qing Cai , Yang Jian , Yang Bi Neng , Long Ming Hua , Zheng Hui Min , Liu Cheng Wei , Wei Min
Published: November 2010

The effects of [Si], [Ti] content on viscosity, melting temperature, and flow properties of hot metal were studied in the laboratory in allusion to the feature that hot metal bearing Ti becomes viscous easily. The solubility of titanium in molten iron was calculated with thermodynamic and relationship between solublity and temperature was disscused. The results show molten iron becomes viscous mainly controlled by the dissolution and precipitation of titanium. [Si] has a weakening effect on the solubility of titanium. Titanium will have less influence on the viscosity of hot metal whenΣ [Si+Ti] content is about 0.6 % and [Ti] content is below 0.29%. The choice of appropriate blast furnace temperature is the crux of avoiding hot metal containing titanium becomes viscous, hot metal pit adhesion, slag iron is difficult separation and so on.
Relation between Medium-Range Order and Crystallization in Al-Ni Based Glass-Former Alloys
Authors: Wang Sheng Hai , Wang Jian Min , Wang Wei
Published: November 2010

The structure evolutions of Al83Ni10Ce5Si2, Al83Ni10Ce7, Al85Ni10Ce5, Al87Ni7Nd6 and Al87Ni5Co2Nd6 metallic glasses have been studied in detail. The studies establish a relation between the amount of medium range order (MRO) and crystallization mode. An increased amount of MRO suppresses the precipitation of primary fcc-Al and transforms the crystallization mode from a primary crystallization (Al87Ni7Nd6) to a eutectic crystallization (Al87Ni5Co2Nd6); while a decreasing amount of MRO promotes the precipitation of primary fcc-Al and transforms the crystallization mode from a eutectic crystallization (Al83Ni10Ce7 and Al85Ni10Ce5) to a primary crystallization (Al83Ni10Ce5Si2).
Tribological Performances and Friction Reduction Mechanism of N-Al2O3/FeS Solid Lubrication Duplex Layer
Authors: Hu Chun Hua , Liu Qiu Pu , Jiang Feng , Ma Shi Ning , Qiao Yu Lin , Sun Xiao Feng
Published: November 2010

FeS solid lubrication duplex layer was prepared on the surface of 45 steel by ion nitrocarburizing-ion sulphurizing process. The sulphide grains in micron and nano scale and holes distributing equably on the duplex layer. The n-Al2O3 particles in liquid paraffin oil were set into the holes in micron and nano scale of the duplex layer by using vacuum dipping process to prepare the n-Al2O3/FeS solid lubrication duplex layer. Friction and wear performances of the n-Al2O3/FeS solid lubrication duplex layer were investigated to be excellent under different loads and temperatures. The causes are as follows: the solid lubrication function of FeS solid lubrication duplex layer, the “micron nano bearing” function of the nanoparticles embedded in the micron nano pores of FeS solid lubrication duplex layer, and oil lubrication are integrated by nanoparticles/FeS solid lubrication duplex layer and exert synergic lubrication function under high temperature and over loading condition. so the coefficients of friction and volume loss of the n-Al2O3/FeS solid lubrication duplex layer under load 60N and temperature 150°C are 10% and 31.3% lower than those of the FeS solid lubrication duplex layer lubricated by the n-Al2O3 additive, respectively.
Microstructure Evolution of a Metastable CrMnN Austenitic Stainless Steel during Compression Deformation
Authors: Xu Ming Zhou , Wang Jian Jun , Wang Li Jun , Cui Wen Fang , Liu Chun Ming
Published: November 2010

Microstructural evolution of a metastable 18Cr12Mn0.55N austenitic stainless steel during compression deformation was investigated by transmission electron microscopy (TEM) and X-ray diffraction (XRD). TEM observation showed the occurrence of deformation-induced phase transformation and atypical deformation twin, the deformation-induced phase cannot be identified as austenite or martensite. XRD test showed that the amount of deformation-induced phase is less than the detectable limit of XRD.
Numerical Simulation of Flow Field in Bloom Continuous Casting Mold with Electromagnetic Stirring
Authors: Zhang Jing , Wang En Gang , Deng An Yuan , Xu Xiu Jie , He Ji Cheng
Published: November 2010

A coupled numerical simulation of magnetic field and flow field was conducted basing on Φ250mm bloom during continuous casting with electromagnetic stirring.The distribution of the flow field was analyzed in different current and frequency.At the same current,the velocity first decrease and then increase as the frequency increase along the casting direction.At the same frequency, tangential velocity is dominant in the radial of EMS center,velocity increase with the current. Considered the results of numerical simulation,the optimized EMS parameters of Φ250mm bloom are the stirring current of 480A and the stirring frequency of 3Hz.
High Anticorrosive Properties of Hot-Dip 55 wt% Al-Zn-Si Coatings on Q235 Steel
Authors: Yao Wen Li , Li Qian , Li Mou Cheng , Zhang Jie Yu , Chou Kuo Chih
Published: November 2010

A comparative study of the morphology and anticorrosive behaviour of commercial 55 wt% Al-Zn-Si coatings (CC) and hot-dip 55 wt% Al-Zn-Si coatings (HD) on Q235 steel was performed by using surface analysis techniques and electrochemical measurements. Despite the ingredients of the Al-rich dendritic phase for HD coating similar to the ingredients for CC coating, aluminum content in the Zn-rich phase for HD coating was almost twice higher than aluminum content for CC coating. The difference of surface morphologies and chemical compositions in Zn-rich phases for the two 55 wt% Al-Zn-Si coatings could significantly affect their corrosion properties. The corrosion behavior of the two coatings was investigated in 0.01 mol L-1 NaCl + 0.01 mol L-1 NaHSO3 aqueous solution. Both polarization curve and electrochemical impedance spectroscopy results indicate HD coatings had much higher corrosion resistance than CC ones.
Mechanical Properties of UPR Composite Synergistically Toughened by Rigid Nano-Particles
Authors: Peng Ying , Liu Jian Hua
Published: November 2010

The synergistic toughening of UPR composite by rigid particles of organic PA6 and inorganic nano-SiO2 was studied. The effects of PA6 and SiO2 on the notched impact and tensile strength of the UPR composite were studied by means of the mechanical properties test. The experimental results indicated that the notched impact strength was improved and its effect was evident when 7-9％rigid particles were applied and the tensile strength was improved when the 2-5％ rigid particles were applied. The composite of PA6/SiO2 ( 2/1) exhibited good mechanical property in the synergistic toughening. By the micromechanical analysis of composite, we thought that the stiffness of composite materials was determined by the stress suffered the rigid particles and the deformation of UPR polymer phase.
Effect of Thermal Relaxation on Propagation of Longitudinal Displacement Wave
Authors: Xue Bing Bing , Xu Hong Yu , Fu Zhu Mu , Sun Qing Yong
Published: November 2010

The micropolar elasticity theory takes into consideration the granular character of the medium, describes deformations by a microrotation and a microdisplacement. A model can be applied to the coupled theory as well as to five generalizations, such as L-S theory, G-L theory, H-I theory, G-N theory of type (II) and C-T theory. And if some parameters in this model are taken as given values, we can easily deduce the known models of Kelvin-Voigt model and other generalized micropolar/magneto/thermo/viscoelastic theory model. Employing the model of micropolar generalized magneto-thermo-elasticity, reflection and refraction of longitudinal displacement wave at interface of two welded micropolar elastic media are studied. The amplitude ratios of reflected and refracted micropolar magneto-thermoelastic longitudinal displacement waves, longitudinal microrotational waves and the coupled transverse and microrotational waves are studied for incident longitudinal displacement wave. The numerical results show that the effects of thermal relaxation times are very significant on the amplitude ratios.
Drag Reduction Effect of Dimples Arranged in Two-Dimensional Quasicrystal Structure
Authors: Xue Wen Hui , Geng Xing Guo , Li Feng , Li Jie , Zhang Yao , Wu Jun
Published: November 2010

Rotating fluids experiments were carried out by CAP2000+ cone viscometer, to examine the drag reduction properties of dimples arranged in quasicrystal structure. The dimples were fabricated on the surface of duralunmin (LY12) plates. Compared with the periodic arrays, the dimples arranged in quasicrystal structure, especially the 12-fold quasicrystal structure, could significantly reduce the wall shear stress. And the relative drag reduction efficiency changes periodically with the depth of dimple. Flow-visualization experiment verified that the coherent effect of dimples arranged in quasicrystal structure and the fluids could efficiently inhibit the extending intensity of radial secondary flow, which strengthens the drag reduction effect.
Measurement of Surface Roughness by Computer Vision in Planning Operations
Authors: Chen Xiang Wei , Zhang Zhi Kui , Liu Zhao Hui
Published: November 2010

Detection and Recognition of the surface roughness in the images is a topic which has received a lot of attention in the field of image processing. In this paper, a new non-contact measurement method of surface roughness, by texture analysis, is developed based on Charge Coupled Device (CCD) image in planning operations. The surface image of the workpiece is first acquired using the A102f CCD digital camera. The image captured will be converted to others kinds of images (Binary, and Gray scale) to be suitable for the detection algorithms used for the different types of surface. The main Image processing approaches is used such as Smoothing process, Noise reduction, Edge detection, Region Splitting, and Hough Transform etc. The predicted surface finish values using this measurement method are found to correlate well with the conventional stylus surface finish ( Ra ) values.
Study on Bubble's Stability in Process of Preparing Foam Aluminum by Powder Metallurgy Method
Authors: Wei Li , Sun Yu
Published: November 2010

In this paper, the bubble’s stability is studied in the process of preparing foam aluminum by powder metallurgy. In this work, carborundum particles, soot powder and carbon fiber are added into pure aluminum powder, respectively. The microstructure of cell wall of foam aluminum, the viscosity and surface tension of melt is investigated. It is discussed the bubble stability which is controlled through adding SiC particles, soot powder and carbon fiber, and the mechanism of bubble’s stability is analyzed. The experiment results showed that the homogeneity of bubble holes of foam aluminum is better than that which is obtained by adding SiC practical and carbon fiber into the raw materials. SEM images showed that SiC particles and carbon fiber distribute evenly on cell wall of foam aluminum. It means that during foaming a lot of SiC particles and carbon fiber distribute diffusively in liquid aluminum melted. It increases the viscosity of melt so that stability of bubble is increased.
Ex-Situ Study of Polymeric Syntactic Foams Mechanical Response Under Compression Loading: Effects of Foam Microstructure Using Microtomography Techniques
Authors: Viot Philippe , Chirazi Ali , Dumon Michel , Bernard Dominique , Fascio V.
Published: November 2010

Syntactic foams are widely used in many impact-absorbing applications and can be employed as sandwich core. To improve their mechanical performances, these composite sandwich structures have to be modelled. This approach requires the characterisation of the foam behaviour. Moreover, the microstructure of the syntactic foam has an influence on its macroscopic behaviour; the foam density, the diameter of the porosities, their distribution in the material have to be taken into account.
The Study of Electrochemical Property of Organic Coating on Magnesium Alloy
Authors: Lou Bai Yang , Tang Yao , Miao Ke Zai , Xu Bin
Published: November 2010

Magnesium Alloys are of low density, high specific strength and high strength, leading to much application prospect in industry and civilian use. However, the alloys are restrictedly used because of easy corrosion. In this paper, The Organic coatings on Magnesium Alloys are made. The electrochemical properties of organic coatings are researched by scanning electron microscope (SEM), stereoscopic microscope and electric-chemistry Work station. The research results show that the curves of open-circuit current to time and Tafel polarization shuffle more for the Pu and ER/PU coatings than for base alloy. With addition of the coating, the magnesium alloy has much low corrosion current density (icorr) and high polarization resistance (Rp), and then its Anti-corrosion Property is evidently improved.
Effects of Modification on Structure and Properties of Ramie Fiber/Polypropylene Composites
Authors: Lei Wen , Jin Xiao Ming
Published: November 2010

Ramie fiber and polypropylene were used as raw materials,ramie fiber/polypropylene composites were prepared by compression molding process,the effects of treating the ramie fiber with silane coupling agent and compatibilizing the composite with maleic anhydride gafted polypropylene(MAPP) on the structure, melting and mechanical properties of the composites were studied，the effects of immersion time in water on the mechanical properties of the composites were also investigated.The results show that,both the modification with coupling agent and by means of compatibilizing agent can strengthen the interfacial bonding between the fiber and matrix in the composite,and also improve its thermal stability.All the modified composites have greater strengths and moduli than the unmodified ones when immersed in water for any periods,especially the impact strength of the MAPP compatibilized composite not only increases with immersion time in water dramatically,but also is improved from that of the unmodified one by 104.84%,239.40%,294.48% and 320.01% respectively when immersed in water for 0,7,14 and 21d.
Effect of Sr on the Microstructure and Properties of Hypereutectic Al-20 wt% Si Alloy
Authors: Li Xiao Song , Cai An Hui , Liu Gang , Zhou Yong , Zeng Ji Jie
Published: November 2010

The effect of Sr on the microstructures and mechanical properties of Al-20 wt% Si alloys were investigated. The results show that with increasing of the Sr content, the primary silicon firstly changes from polygonal block or large plate to small block, then to large polygonal block, and a large number of honeycomb-like on the primary silicon block. The eutectic silicon firstly changes into a fine start with a long needle-like fibrous or branched further to a short stubby dendrite or worm-like, continuously columnar dendrite α of quantity increase. In addition, with increasing the Sr content, the elongation of alloy increases, but there are ups and downs, the tensile strength changes little after the first sharp increases in hardness is parabola. When the Sr content is between 0.04 wt% and 0.06 wt%, the morphology and mechanical properties is the most ideal.
Research on Predicting the Stability of Partially Stabilized Zirconia Based on SVM
Authors: Guo Sheng Hui , Li Dong Bo , Liu Li Jun , Peng Jin Hui , Zhang Li Bo , Chen Guo
Published: November 2010

The stability is one most important product performance index, which can directly determine the quality of the partially stabilized zirconia (PSZ), and the stability of PSZ is always fluctuating in the commercial process, so how to accurately, quickly and easily predict the stability of PSZ in the preparation process is very important. In the present paper, a new mathematical model to predict the stability of PSZ was proposed, based on statistical theory (SLT) and support vector machine (SVM) theory, which relates the stability of PSZ and the influence factors, such as the holding temperature, rising rate of temperature, holding time, decreasing rate of temperature and hardening temperature. Typical data collected from commercial process were collected for the training samples and test samples. Then testing and analyzing was done. The results showed that the max relative error was 1.80%, the least relative error was 0%, and the average relative error was 0.58%. It is accurate and reliable to predict the stability of PSZ by SVM model. Besides, multiple influence factors can be comprehensively considered in the SVM model, thus a new highly effective method for predicting the stability of PSZ is provided for commercial application.
Flow Behavior of Heterocyclic Aramid Concentrated Solution
Authors: Chen Lei , Hu Zu Ming , Gao Bao Shan , Tang Guo Ping , Yu Jun Rong , Zhu Jing
Published: November 2010

By means of HAAKE RS105L cone and plate rheometer the rheological behavior of heterocyclic aramid concentrated solution, including viscous flow activation energy, non-Newtonian index, structural viscosity index of the heterocyclic aramid solution were studied. The effect of concentration and temperature of the solution and molecular weight of the polymer on its non-Newtonian behavior was investigated. The results showed that heterocyclic aramid concentrated solution prepared via low temperature condensation was non-Newtonian fluid. With the decrease of temperature, increase of solution concentration and heterocyclic aramid molecular weight, the deviation of the solution from Newtonian behavior decreased. The molecular weight of the polymer and the concentration of the solution affected the non-Newtonian behavior more intensively.
Reaction Synthesis and Oxidation Behaviours of Ludwigite
Authors: Liu Ran , Wang Xing Juan , Gao Yong Liang , Lu Qing , Xue Xiang Xin
Published: November 2010

Using ludwigite as raw material, the phase transformation and mass loss rate of ludwigite in the process of oxidizing roasting are investigated by DTA, isothermal TG, scanning electron microscopy (SEM), X-ray diffraction (XRD) techniques. The results showed that magnetite is transformed into hematite, serpentine is decomposed into forsterite at lower temperature (T＜700°C). The weight of ludwigite has a small loss below 600°C. The decomposed of szaibelyite dehydrated and formed into suanite about 700°Cis the main reason of causing ludwigite mass losses. By comparing the curves of ludwigite at different temperature from 700 to 900°C, the process of oxidizing roasting can be divided into three phases: characterized by a period of fast weight loss, and then followed by a mass gain. Finally, weight of sample is no longer change with prolongation of time. The final weight loss is 6.062%, 6.658% and 7.442% respectively for test temperature. Suanite can not be decomposed to form B2O3 and volatilized when the temperature of oxidizing roasting is below 1142 °C. It is found by XRD that paigeite and magnoferrite are the most stable composition without deterioration on oxidizing roasting. The experiment results can provide theoretical references for agglomeration and blast furnace smelting of ludwigite.
Preparation and Property of SnXCuNiBi Solder Alloy
Authors: Chen Hai Yan , Jie Xiao Hua , Zhang Hai Yan , Chen Yu Long , Guo Li
Published: November 2010

Lead-free solder is meeting the requirement of environmental protection, but the property performance of existing lead-free solder is hardly comparable to those of lead solder. In this paper, 0.6% Bi was added into SnXCuNi solder alloy to produce lead-free solder at low cost and high performance. Microstructure, phase composition, melting point, wettability and characteristics of weld interface have been studied and analyzed. The results show that SnXCuNiBi solder alloy are mainly composed of βSn, SnX, Cu6Sn5 and SnBi. The addition of Bi reduces the melting point and improves the wettability of the solder. The main component of the joint interface of SnXCuNiBi/Cu system is Cu6Sn5, which has shown the capability to keep relatively high shear strength at the joint interface.
Nanostructure formed by phase separation of fcc-Al from eutectic crystallization in the Al85Ni10Ce5 metallic glass
Authors: Wang Sheng Hai , Wang Wei , Wang Jian Min
Published: November 2010

A nucleation-growth control for Al85Ni10Ce5 glass has transformed to a growth control for Al83Ni10Ce5Si2 glass. That’s to say a small quantity of Si addition can successfully separate the Al phase to single precipitate from a eutectic precipitation composited of Al and other intermetallic compound to synthesize nanostructured materials, characteristic of microstructures with finely dispersed nanoccrystalline Al in an amorphous matrix. Favorably，no evident decrease of glass forming ability is observed in the transformation. We suggest that the Si atoms solve into Al lattice to sever as pre-exist nucleus for fcc-Al, in the same time; a nucleation reaction of fcc-Al is accompanied to compensate the nucleation rate.
Optimization of Piston Structure Aimed at Reducing Oil Consumption
Authors: Zhao Xu Dong , Liu Shi Ying , Song Shu Feng , Xiong Pei You
Published: November 2010

Oil consumption of one certain diesel engine has been reduced by optimizing piston structure and piston kids clearance. The oil consumption principle inside the liner of engine was analyzed. Engine test was applied to validate the effect of the optimization. Due to the analysis, enlarge the pressure grads between piston top land and the 2nd land can push the 1st ring to the groove downside steadily. Adding or enlarging oil containing pocket above and below oil ring groove can reduce the oil pressure in these areas. Reasonable and large clearance between piston top land and cylinder liner help the gas burn completely.
Non-Isothermal Crystallization Behavior in Zr55Cu30Ni5Al10 Bulk Metallic Glass
Authors: Tao Ping Jun , Yang Yuan Zheng , Bai Xiao Jun , Mu Zhong Xin , Li Guo Qing
Published: November 2010

A Zr55Cu30Ni5Al10 bulk amorphous alloy was prepared by using copper mold suction casting and the X-ray diffractometer (XRD) was utilized to determine its structure. The non-isothermal crystallization behavior of the amorphous alloy was studied via a differential scanning calorimeter (DSC) by Kissinger and Ozawa methods. The results showed that all the thermodynamic parameters move to higher temperatures with increasing heating rates. The activation energies for crystallization calculated by Kissinger and Ozawa method are 291.27 and 288.53 kJ/mol, respectively. With the increase of heating rate, the rate of x vs. T descends. The crystallization mechanism is typical nucleation and growth of crystalline grains, among which the latter dominates the total crystallization process.
Experimental Study of Lattice Constant Dependence on the Grain Size in some Nanocrystallites
Authors: Zhu Yu Hua
Published: November 2010

The influence of grain size on the lattice constant in some nanocrystallites was studied by in experiment. It is found that the lattice constant of NaCl, CsCl structure ionic crystallites decreases with the reduction of the grain size. The lattice constant of ultrafine iron and nickel particles increases with the reduction of the grain size. As to the experiment result of g-Fe2O3 nanocrystallites, the lattice constant increases with the decreasing of the grain size. It is opposite to the theoretical result of ionic crystallites, which reason is that the combination of most of atoms in g-Fe2O3 is by the covalent bond other than electrovalent bond.
Influence of Isothermal Annealing on the Micro-Hardness and Friction Property in CuZrAl Bulk Metallic Glass
Authors: Tao Ping Jun , Yang Yuan Zheng , Bai Xiao Jun , Wen Jian Guo , Ru Qiang
Published: November 2010

A Cu55Zr40Al5 bulk metallic glass (BMG) was prepared by using copper-mold suction-casting and the structure and thermal stabilities of the amorphous alloy as well as the effect of isothermal annealing on its micro-hardness and friction property were studied. The results showed the glass transition temperature, onset temperature of exothermic reaction, and temperature interval of supercooled liquid region are 746.8 K, 793.5 K and 46.7 K, respectively. The BMG exhibits a micro-hardness value of 483.5 Hv and an average friction coefficient of 0.495. After isothermal annealing treatment, the micro-hardness has been enhanced and presents an upward trend with increasing the annealing temperatures. Meanwhile, the friction coefficients can be significantly decreased and the anti-wear property has been enhanced evidently.
Theoretical Study of Lattice Constant Dependence on the Grain Size in Some Nanocrystallites
Authors: Zhu Yu Hua
Published: November 2010

The influence of grain size on the lattice constant in some nanocrystallites was studied by computing the interactive cohesive energy of the nanocrystallites. The relationships of the lattice constant with the grain size in NaCl, CsCl structure ionic crystallites, FCC, BCC structure metal crystallites and FCC, BCC, SCC structure molecular crystallites was studied respectively. The results are in good agreement with the above experimental ones qualitatively.
Formation of Precipitations in Ultra-Low Carbon Microalloyed Steels Treated by Rapid Tempering
Authors: Xing Shu Qing , Chen Zheng Zong , Ma Yong Lin
Published: November 2010

The aim of the determination is to study formation of precipitations by rapid tempering using thermal simulation tester and effects of precipitations on lower-temperature toughness property. A ultra low carbon microalloyed quenched steel containing alloying elements, such as 0.06wt%C-0.04wt%Nb-0.06wt%V-0.008wt%Ti, is tempered at 620°C for holding time 70min in conventional resistance furnace , and tempered rapidly at 620°C for 40s、80s and 120s, respectively. Both microstructures and impact properties were also investigated. It was observed that the nanoscale cementite particles were obtained by rapid tempering for 40s. Furthemore, the Charpy impcat energy of these specimens holding time 40s is higher than that of others. In comparison with conventionally processed, rapid tempering for low carbon alloyed steel can achieve good toughness due to the nanoscale cementite particles and offer the potential advantage for significant time and cost savings.
The Investigated Microstructure and Mechanical Properties of Al2O3/20wt% TiO2 Nanocomposite Coating
Authors: Dejang Nuchjira , Watcharapasorn Anucha , Wirojupatump Sittichai , Hannula Simo Pekka , Jiansirisomboon Sukanda
Published: November 2010

The incorporation of nano-size TiO2 particles can significantly enhance the microstructure and mechanic properties of Al2O3 coating. Phase transformation from mainly stable α-Al2O3 and anatase-TiO2 in the powders to predominant metastable γ-Al2O3 and rutile-TiO2 in the coatings was observed. Reaction between Al2O3 and TiO2 phase also occurred producing new phase Al2TiO5 phase. Microstructural investigation showed that well separated TiO2 lamellas were homogeneously dispersed between Al2O3 lamellas. It was found that the plasma-sprayed composite coating possessed better wear resistance than that of monolithic Al2O3 coating. The addition of TiO2 was found to improve friction coefficient, wear resistance and fracture toughness.
Study on Thermal Resistance of Basalt Filament Yarn
Authors: Li Xin E
Published: November 2010

Basalt filament yarn is a new type of high-performance fibers, which is formed by the direct drawing of basalt rock at high temperatures. It is a natural and environmentally friendly textile material. This paper mainly focuses on thermal resistance research of basalt filament yarn that is heated at various temperatures. The change of color and appearance of heated basalt filament yarn was described. The mechanical properties of heated basalt filament yarn were tested. The results showed that although the mechanical properties of basalt filament yarn decreased with the temperature rising, still remained high tensile strength within a certain temperature range. Basalt filament yarn possess higher tenacity under 325°C. Basalt filament yarns still possess certain tenacity when they were placed at 500°C condition. So basalt filament yarn can be used as heat-resistant materials, such as filtration materials for high-temperature gas and liquid, fire-proof fabrics and so on.
Research on the Surface Quality of ESR Large Slab Ingots
Authors: Jiang Zhou Hua , Geng Xin
Published: November 2010

A special bifilar 40t electroslag remelting(ESR) furnace for slab products has been fabricated to produce heavy plates for special application. The ESR slabs with the maximum thickness of the world in size of 980 mm thickness, 2000 mm wideness and 2800 mm length have been produced successfully. However, the ingots surface quality is a serious problemn in ESR process for large slab ingots, for ingot and mold with a relatively mobile, larger ingot contraction and thicker slag skin. Using CaF2-CaO-Al2O3-SiO2-MgO slag, suited remelting rate, lower filling ration, smooth movement of mold and adjusting taper of the mold and are necessary for improving surface quality of the ESR large slab ingots.
Underground Pumping Range Research and Practice
Authors: Yang Jia , Qiu Li Jun
Published: November 2010

This paper describes the extended-range device applications in the oil wells pumping relevant content to discuss the extended-range devices in the downhole process, the output rod and pump rod connecting relationship between the introduced pump barrel length of the selection method, extended range in the Underground to add a device later, washed away from the rod anti-extraction method and so on.
Fundamental Aspects of Stray Current Corrosion on Buried Pipeline
Authors: Zhu Qing Jun , Cao Alin , Wang Zai Feng , Song Ji Wen , Chen Sheng Li
Published: November 2010

Stray current is one of the main reasons in pipeline failure. In pipeline design and maintenance, it is important to know the fundamentals influencing stray current corrosion. However, it is difficult to control stray currents because many factors can affect its inflow points, outflow points and current densities. Several fundamental aspects, such as soil resistivity, coating worn rate, buried depth and horizon distance have been studied in order to find useful information in pipeline design. The results show stray current can be influenced by soil resistivity, coating worn rate and buried depth. It is suitable to control stray current corrosion by increasing soil resistivity, buried depth, horizon distance and decreasing coating worn rate. However, there are boundary values in controlling stray current corrosion by increasing soil resistivity, buried depth and horizon distance. For example, in this laboratory study, the boundary horizon distance is 200mm.
Microstructure and Crystallographic Texture of Oriented Silicon Steel Produced by TSCR
Authors: Yu Yong Mei , Xu Yun Bo , Li Chang Sheng , Wang Guo Dong
Published: November 2010

The microstructure and textures of oriented silicon steel produced by Thin Slab Casting and Rolling (TSCR) were studied in laboratory. The fractions of equiaxed grains and columnar grains are close to 35% and 65% respectively in as-quenched ingot after being pulled out from the mould. The equiaxed grains and no texture gradient from surface to center can be observed for the 3-pass hot-rolled strips, and the inhomogeneities of microstructure and texture in thickness are relatively clear for the 7-pass samples. The subsurface texture of the hot-rolled sample contains of e (TD// <110>) fibers. The texture of the cold-rolled samples mainly consists of a (<110>//RD) and g (<111>//ND) fibers, and Goss texture ({110}<001>) disappears. The strong a fiber, weak g fiber and minor {001}<110>can be found in all layers in the cold-rolled condition.
Crystallographic Texture in SrM Hexaferrite Doped with Zn2+ Ions
Authors: Jin Ming Lin , Zhu Cun Fu , Wang Zhan Yong , Chen Qi Zhong , Liu Ke Jia
Published: November 2010

The Sr0.75La0.25Fe11.75-xCo0.25ZnxO19 hexaferrites are prepared by the ceramic process. Influences of the substitution of Zn2+ ions on crystallographic texture have systematically been investigated by pole figure analysis. The (008) and (107) pole figure shows that the pole intensities are axisymmetric at the center of c axis. With the increase of x, the lattice parameters a and c increase gradually till x=0.15. Excessive Zn2+ addition induces the much coarse grain. The easy-axis alignment of grains decreases from 77.5% to 75.5% for the substitution of Zn2+ ions from 0 to 0.25. When Zn2+ content was from 0 to 0.25, the magnetic properties of Br and (BH)max were increased, while Hcb and Hcj were decreased till x>0.2.
Research in Shape Meter Roll Deflection Compensation Model
Authors: Liu Jia Wei , Zhang Dian Hua , Wang Peng Fei
Published: November 2010

In flatness measurement system, the flatness measuring signal can be affected by the flatness roll deflection. The flatness roll stress was analyzed and the flatness roll deflection model was obtained by using the influence function method in this paper. The model has been developed based on the deformation of flatness roll in rolling and compensating curve has been obtained. The results indicated that the setting curve of flatness is preferably accordant with the curve of online measuring flatness, and good strip flatness can be obtained.
Deformation Behavior and Dynamic Recrystallization of Hot Deformed GH625 Superalloy
Authors: Guo Qing Miao , Li De Fu , Guo Sheng Li
Published: November 2010

Microstructure evolution during dynamic recrystallization (DRX) of hot deformed GH625 superalloy was investigated by optical microscope (OP) and transmission electron microscope (TEM). Hot compression tests were conducted using Gleeble-1500 simulator. It was found that the nucleation mechanism of DRX for the alloy deformed at 1150°C is composed of discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX) in the vicinity of the serrated grain boundaries. With the increasing strain, the fraction of the DRX grains increases, while the size of the DRX grains almost remains in the same range. As the deformation temperature increasing, the size and fraction of the DRX grains increase, and no precipitation of intergranular carbides are found when the deformation temperature increases to 1150°C. At lower strain rate, the size and volume fraction of DRX grains decrease with the increasing strain rates. However, the size and volume fraction of DRX grains increase at higher strain rates due to the deformation thermal effect.
The Effect of (Li,Ce) Doping in Aurivillius Phase Material Na0. 5Bi4.5Ti4O15
Authors: Gai Zhi Gang , Feng Yuan Yuan , Wang Jin Feng , Wu Hong
Published: November 2010

Na0.5Bi4.5Ti4O15-based materials with A-site vacancy were synthesized using conventional solid state processing. The (Li,Ce) modification of Na0.5Bi4.5Ti4O15-based materials resulted in the obvious improvement of the piezoelectric activity and dielectric permittivity. The dielectric and piezoelectric properties of Na0.5Bi4.5Ti4O15-based ceramics exhibiting a very stable temperature behavior, together with its high TC ~641oC, excellent piezoelectric coefficient ~28pC/N and very low temperature coefficient of resonant frequency, making the (Li,Ce) modified Na0.5Bi4.5Ti4O15-based ceramics a promising candidate for high temperature applications.
Antiferromagnetic Transition and Martensite Transformation in γ-Mn-Fe Alloys
Authors: Gu Su Yi , Zhang Ji Hua
Published: November 2010

The detailed investigation of internal friction and relative dynamic modulus has been carried out for the γ-MnFe alloys with 61.4at%~86.4at%Mn in the temperature range from -50 to 250 using LMR by means of force vibration method. The internal friction was found to exhibit in turn three peaks from higher temperature to the lower temperature on the internal friction-temperature curves. They are PA,PM and PT progressively. It can be concluded that PA may be connected with the stress-induced motion of magnetic domain. The PM was suggested to be originated from the stress-induced movement of interfaces between the fcc and fct phases. The PT is due to a relaxation process associated with the movement of the {101}-twin boundaries in the fct phase or fcc antiferromagnetic phase.
Investigation about Electro-Deposition Properties of Special Nickel Electroplating Coating for 45# Steel with Different Surface Roughnesses
Authors: Zhao Wei Lin , Huang Hui , Wang Zhen Lin
Published: November 2010

The effects of the surface roughness on electro-deposition properties of the special nickel electroplating coating for the 45# steel were investigated. The results indicate that the surface roughness has great effects on the corrosion resistance and the surface hardness of the coating, the adhesion force between the coating and the substrate. Among the three 45# samples with different surface roughnesses, the sample with moderate surface roughness (Ra≈0.1um) has the relatively higher corrosion resistance, surface hardness and adhesion force than the samples with higher and lower surface roughness.
Study of Structure and Properties of New Rolling-Cut Shear
Authors: Chu Zhi Bing , Huang Qing Xue , Zhang Zhi Yuan , Li Dan
Published: November 2010

Based on rolling-cut shear simulation, using a kind of single-shaft and double eccentricity rolling-cut shear, which adopts a new structure of asymmetric feature and negative bias, as the calculating model by establishing motion path equation of spatial shear mechanism, comparing with the steel shear forces, link forces and horizontal link force components with or without asymmetric feature, the asymmetric formulation is deduced. Such asymmetric crank structure can decrease horizontal force component between the linkages during rolling-cut process, increase the effective drive force on links while it comes to the maximum shear force, and decrease the extrusion of blade arc on steel edge as well. Theoretical analysis and steel-shearing quality at site indicate that asymmetric and negative bias is an important and efficient way to prolong the lifetime of blade, decrease blade wear, improve shearing quality, and maintain the constant clearance between blades.
Study on Probabilistic Optimal Design of Diaphragm Spring
Authors: Wang Ruo Ping , Zhang Guo Dong , Gao Xiang , Xia Chang Gao
Published: November 2010

The mathematical model of probabilistic optimization is established for diaphragm spring. The process and the method of design with an example are presented. The result shows the model and the method of design are feasible, and perfect optimal result is attained. Vehicle has mass production and its conditions of use are changeable, which determine design parameters and operating parameters of its parts have complex randomness. Diaphragm spring clutch is now widely used by many kinds of vehicles. Research of diaphragm spring parameters’ probabilistic and statistics model and the study of its optimal design have great significance for the design, R & D, manufacturing and use of automotive products and parts. Studies in the references[1,2,3] have shown that the root cause of diaphragm spring’s fatigue fracture is the original crackles near the concave inner edge point, so there is a need to do probabilistic optimal design for diaphragm spring’s structural parameters to improve the fatigue life.
Preparation and Characterization of (Ba0.88Ca0.12)(Zr0.12Ti0.88)O3 Powders and Ceramics Produced by Sol-Gel Process
Authors: Yang Ren Bo , Fu Wei Guo , Deng Xiang Yun , Tan Zhong Wen , Zhang Yan Jie , Han Li Ren , Lu Cheng , Guan Xiao Fen
Published: November 2010

The (Ba0.88Ca0.12)( Zr0.12Ti0.88)O3 powders and piezoelectric ceramics were prepared by sol-gel process. The reaction process was analyzed with the help of thermo gravimetric and differential scanning calorimetry. X-ray diffraction characterized results showed that the structure of the (Ba0.88Ca0.12)( Zr0.12Ti0.88)O3 powders was perovskite structure and the particle size was approximately 37nm. Piezoelectric measurements revealed that Curie temperature and the maximum piezoelectric coefficient d33 is 95°C and 215pm/V, respectively.
Nanometer Anatase Titania Synthesis by Reverse Titration Method and Evaluation of their Photocatalytic Activity
Authors: Ji Jin Gou , Yang Bin , Yuan Xiao Yu , Xia Zhi Ning , Shi Chao Hui , Liu Huan
Published: November 2010

The nanometer titanium dioxide (TiO2) was prepared by reverse titration method with titanium trichloride and titanium tetrachloride at low temperature. The prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and laser diffraction particle size analyzer, the photocatalytic activity of the samples was also evaluated. The results showed that the prepared TiO2 was nanometer anatase titania with an average particle size of 56.39 nm and the zeta potential of +39.42 mV. The nanometer anatase titania had the best photocatalytic activity than the TiO2 prepared by reverse titration or forward titration with titanium tetrachloride and a good stability.