bluuebunny/crossref_metadata_2025 huggingface dataset:
Influences of Micro-Arc Oxidation on Pre-Corroded Fatigue Property of Magnesium Alloy AZ91D
Authors: Chen Yue Liang , Zhang Yong , Li Yan , Zhang Tai Feng
Published: November 2010

The surface morphologies of micro-arc oxidation coatings and chemical oxidation coating formed on AZ91D alloy were observed by scanning electron microscopy. The fatigue properties of both specimens with micro-arc oxidation coatings and chemical oxidation coating after the pre-corroded treatments in neutral salt spray test were investigated comparatively. The result shows that pre-corrosion treatment decreases the fatigue life, but the pre-corroded fatigue life of specimens with chemical oxidation is lower than that with micro-arc oxidation. The thickness of micro-arc oxidation coatings has no obvious influence on the pre-corroded fatigue life of AZ91D alloy.
In Air Template-Free Synthesis of In2S3 Hierarchical Nanostructure from InCl3·4H2O and Thiourea
Authors: Li Shi Yin , Du Zhen Ni , Zhang Yong Cai
Published: November 2010

A novel template-free method, which was based on heating the mixture of InCl3•4H2O and thiourea in air from room temperature to 200 or 250 °C, coupled with a subsequent washing treatment using distilled water and ethanol, was proposed for the synthesis of In2S3 hierarchical nanostructure. X-ray diffraction and field emission scanning electronic microscopy demonstrated that the obtained products were pure cubic phase In2S3 urchin-like clusters built up by mainly nanoflakes (about 12–47 nm thick). UV-vis absorption spectra disclosed that the as-prepared In2S3 urchins had optical band gaps in the range of about 2.18–2.26 eV.
Phase Evolution and Formation Mechanism in Acicular Mullite Prepared from Kaolinite via Wet Chemistry Method
Authors: Dai Xiao Chun , Zhou Zhu Fa , Wang Shu Mei , Tian Ran Ran , Wang Chun Rong , Li Yan Jie
Published: November 2010

Mullite was synthesized by firing precursors prepared from kaolinite via a wet chemistry method at various temperatures. The acicular mullite grains were formed in samples with addition of AlF3 by this process. The phase evolution and morphology of the fired samples were investigated. For the samples without AlF3, the mullitization began to occur at 1300 and almost completed at 1550 , the grains formed were normal-shaped. For the samples with AlF3, acicular mullite was formed, and mullitization began to occur at 1100 and completed at 1250 . The growth of the acicular mullite was associated with a liquid phase. The formed acicular mullite was alumina-rich and had a composition of about 73.4 wt% Al2O3 and 26.6 wt% SiO2 (Al2O3/SiO2=1.65, molar ratio).
Preparation of Nano-Al2O3-Coated ZrO2 Modified by Silane Coupling Agent
Authors: Tian Ran Ran , Zhou Zhou Fa , Wang Shu Mei , Dai Xiao Chun , Wang Chun Rong , Li Yan Jie
Published: November 2010

Core-shell nano-Al2O3-coated ZrO2 materials were prepared via a liquid co-deposition method using ZrO2 as cores. Surface of ZrO2 was modified by silane coupling agent. The mechanism of A-151[CH2=CH-Si-(OC2H5)3] was studied under the condition of HAc. The composite powders were characterized by FT-IR, TEM, EDS and SEM. TEM observation confirmed that amorphous Al2O3 layer deposited on the surface of ZrO2 and the thickness of the Al2O3 coating ranged from 5 to 10 nm. After sintered at 1650°C for 10 h, the size distribution narrowed down and the compactness of composite sintered body was better in comparison with pure zirconia.
Synthesis and Characterization of Nanocrystalline ZnO Powders by a Novel Combustion Synthesis Method
Authors: Wang Bing , Tang Li Dan , Wang Jian Zhong
Published: November 2010

Nanocrystalline ZnO powders have been synthesized by a novel combustion synthesis method using glycine and urea as mixed fuels and zinc nitrates as oxidant. The as-synthesized ZnO powders are characterized by DSC, XRD and SEM. Results show that the as-synthesized ZnO powders show well crystalline with hexagonal crystal structure and purity without any other impurities and the particle sizes are about 50~70nm calculated by the Scherrer formula.
Adsorption of Methylene Blue from Aqueous Solution onto Peracetic Acid-Modified Loosestrife Powder - A New Adsorbent
Authors: Xie Hui Jun , Tan Wei , Zhang Jian , Niu Hong Bin
Published: November 2010

Modified loosestrife powder (MLP), as a new adsorbent, was prepared from dry loosestrife powder by oxidization treatment using peracetic acid with tetrahydrate manganese acetate as catalyst. IR spectra analysis and Boehm titration method were employed to explore MLP’ surface acidic functional groups. Batch adsorption experiments were carried out for the removal of Methylene Blue (MB) from aqueous solution by MLP. Equilibrium experimental data were better represented by Freundlich isotherm using linear methods. Thermodynamic parameters such as G, H and S were also calculated. The results showed that the adsorption of MB onto MLP was efficient and could serve as a promising low-cost adsorbent.
Experimental Researches on Detonation of Aluminized Explosives to High-Speed Flyer Impact
Authors: Men Jian Bing , Jiang Jian Wei , Wang Shu You
Published: November 2010

In present paper, aluminized explosives with separator inside are detonated by plane wave loads from metal flyer impacts. Four types of aluminized explosives(THAL、H-6、HBX-1、HBX-3) that used widely in warheads are test experimentally in order to obtain the critical thickness of separator(thicknesses L50-50% possibility of detonating). The critical separator thicknesses of detonating four types of aluminized explosives are calculated through statistical method according to experimental data. Stability sequence for these four explosive were determinate according to anti-detonation capability. The experimental results provided reference for the selection of explosive and structural design of warhead.
Effect of Anneal Time on Photoelectric Properties of SnS:Ag Thin Films
Authors: Jia Hong Jie , Cheng Shu Ying , Lu Pei Min
Published: November 2010

SnS and Ag films were deposited on glass substrates by vacuum thermal evaporation successively, and then the thin films were annealed at 260°C in N2 for different times (60min, 120min, 180min) in order to investigate the influence of annealing time on the silver-doped SnS (SnS:Ag) films. The obtained films annealed at different times are polycrystalline SnS with orthogonal structure, and the crystallites in the films are exclusively oriented along the {111} direction. With the increase of annealing time, the uniformity and crystallization of the films are improved, the carrier concentration and mobility of the films first rise and then drop, whereas their resistivity and direct bandgap energy Eg show the contrary trend.
Integration of CuO Thin Film and Bi2Te3 for Enhancing the Thermoelectric Conversion Efficiency of Thermoelectric Generator
Authors: Chang Ho , Cho Kung Ching , Yu Chih Jung , Huang Kuohsiu David , Chen Chieh Chen
Published: November 2010

The paper deals with a coating CuO thin film coating on the surface of semiconductor thermoelements (Bi2Te3). In addition, the recycled external exhaust heat is used to generate electric power, further enhancing the thermoelectric conversion efficiency of the thermoelectric generator (TEG). By using electrophoresis deposition, a CuO nanofluid with high suspension stability and good dispersion is deposited on an aluminum foil at a thickness of 0.1mm. This film is conjugated with the top and base of a semiconductor thermoelements (Bi2Te3), and a thermoelectric generator is assembled in parallel with the modified thermoelectric material. Experimental results show that the CuO nanofilm coating on the surface of semiconductor thermoelements can enhance the overall heat conduction and thermoelectric conversion efficiency of thermoelectric generators by as much as 30%.
Quality Determination of Glass/Epoxy Prepreg by NIR Spectroscopy
Authors: Li Wei , Gao Wei Jia , Chen Ping , Sun Bao Lei
Published: November 2010

A near-infrared spectroscopy (NIR) technique has been applied for rapid and nondestructive quality determination of glass/epoxy prepreg. Abundant information related with resin and volatile was observed in the NIR spectra of the prepreg cloth. The partial least square (PLS) regression was used to develop the calibration models by utilizing several spectral pretreatments combined with different spectra ranges. Some unknown samples were analyzed by the NIR method. The mean absolute predicted errors were 0.32% and 0.214% for the resin content and the volatile content respectively. The results of the paired t-test revealed that there was no significant difference between the NIR method and standard method. The NIR method can be used to predict the resin and volatile content simultaneously within 30s. The study indicates that the NIR method is sufficiently for quality determination of glass/epoxy prepreg cloth.
Research on Removal of Sulfide Inclusion in Steel Surface by Molten Salt Electrolysis
Authors: Zhu Li Guang , Gao Hua , Xu Ying , Wang Ling , Liu Xin Sheng
Published: November 2010

Steel including sulfide inclusion was used as cathode, while high density graphite rod was used as anode. Sulfide inclusion in steel surface was removed by molten salt electrolysis in molten CaCl2 at 850 under the stationary voltage. The influences of the voltage and electrolytic time on the process of reaction were investigated. The distributions of the sulfide inclusion were investigated by SEM. The desulfurated ratio was investigated by quantitative metallographic analysis, Cyclic voltammetry was performed to characterize reactions of cathode. The results show that the voltage and the time of electrolysis were in direct proportion with desulfurated ratio. The higher voltage and the longer electrolysis time is, the greater the desulfurated ratio is.
Investigation for Test Sensitivity of Shearography
Authors: Li Hui Juan , Cai Liang Xu
Published: November 2010

To reduce weight and improve strength in the aerospace industry, composite structure connected by glue has gained popularity as a replacement for conventional materials and structures. However, the adhesive bonding process is more susceptible to quality variations during manufacturing than traditional joining methods. The integrality, strength and rigidity of product would be broken by disbonding. Investigate the sensitivity and accuracy of the testing method was more impotent to ensure the product quality and testing efficiency. This paper presents a study of detecting sensitivity of sheargoraphy methods when it is used for inspecting disbondinging on honeycomb structures. The potential of shearography method is also outlined.
Solute Pre-Precipitation and Phase Transformation in a Mg-Zn-Gd Alloy
Authors: Lin Li , Wang Feng , Yang Lin , Chen Li Jia , Liu Zheng
Published: November 2010

A novel precipitation sequence, super-saturated-solution → stacking faults → Mg3Gd, i.e. S.S.S. → SF → β1, was established for a Mg-3Zn-2Gd (wt%) alloy. Solute pre-precipitation can occur during the solidification of as-cast alloy and subsequent solution-treatment, resulting in the formation of lamella structures with …ABCABC… stacking sequence. The lamella structure will transform to the Mg3Gd phase, even that Mg3Gd is not the most stable phase in this serial alloys.
Investigation on Generation Performance for Tubular Direct Methanol Fuel Cell
Authors: Tang Dong , Zhang Yang , Duan Rui Xue , Ni Hong Jun
Published: November 2010

Tubular cathode and plate anode were prepared by gel-casting process and coating process, which used mesocarbon microbead(MCMB) as raw materials, then cathode and anode were assembled to prepare single fuel cell. The generation performance for single tubular direct methanol fuel cell was tested under different electrolyte temperatures, methanol concentrations and oxygen flow rates, and the factors that affected the cell performance were discussed. The results showed that temperature and oxygen flow rate were the important factors of the generation performance in tubular direct methanol fuel cell (TDMFC), but the methanol concentration had a relatively smaller impact on the cell performance. The stability test of the cell after working for 100h shows that the tubular MCMB cathode had a perfect stability.
Determination of Thickness for the Individual Layer of Strained P-Type Al0.11Ga0.89NGaN Superlattice by High Angle Annular Dark Field Scanning Transmission Electron Microscopy
Authors: Liao Hui , Chen Wei Hua , Wei Fen Fen , Hou Juan
Published: November 2010

AlGaN/GaN superlattice are the important structure of optoelectronic devices such as light-emitting diodes and laser diodes. The nanostructure of the superlattice can greatly influences the optical electrical properties of final LD and LED . It is impossible to evaluate their thickness by TEM when it’s aluminum component lower than 14%.We investigated the nanostructure of strained p-type Al0.11Ga0.89N/GaN superlattice grown on sapphire by high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM).By an average filtering technique, the thickness of the AlGaN layers and GaN layers were determined to be 2.409±0.092 nm and 2.371±0.062 nm from the HAADF-STEM images, respectively.
Morphology of the Diamond Thin Films Grown by Microwave Plasma Chemical Vapor Deposition with Different Aftertreatments
Authors: Wu Yu Shiang , Lai Wen Chi , Lee Yuan Haun
Published: November 2010

Diamond films were deposited on (111) silicon wafers by microwave plasma chemical vapor deposition (MPCVD). The deposition parameters included a system power of 1200 W, chamber pressure of 110 torr, H2 flowing rate of 300 sccm, and a CH4 flowing rate of 15 sccm. The diamond particles measured about 5-6 μm, and morphology analysis revealed a rectangular structure stacked regularly on diamond films after deposition. X-ray diffraction (XRD) analysis detected (220) square structures. Annealing at 600 °C improved the quality of diamond film, making the peak of the Raman spectra at 1350 cm-1 sharper and higher. The (220) and (311) orientation structures on the diamond films decreased after annealing broke the surface morphology. To conduct electric and optical experiments conveniently, the deposited samples were immersed in acid (HNA, HF：HNO3：CH3COOH = 3：25：10) to remove the silicon layers. The HNA acid did not corrode diamond films seriously, but slightly damaged the incomplete (220) and (311) structures.
Preparation of Highly Pure Nano-Silver Colloids Modified by Polyethylene Glycol
Authors: Su Wei , Wei Shan Shan , Hu Shun Qin , Tang Jian Xin
Published: November 2010

Stable nano-silver colloids with highly pure silver were synthesized by using polyethylene glycol as solvent, stabilizer and reducing agent. The colloidal nanoparticles need not be separated from the solution and the silver sol can be directly used in antibacterial fields. Tannic acid and ascorbic acid were used as co-reducing agents to improve conversion rate of silver ion. Transmission electron microscopy (TEM) analysis showed that stable spherical metal particles 3-50 nm in diameter with a well-crystallized structure were obtained by using tannic acid as co-reducing agent,15-20 nm in diameter were obtained by using ascorbic acid as co-reducing agent. The X-ray diffraction (XRD) study revealed the formation of metallic silver particles crystallized in the face centered cubic (fcc) structure. The antimicrobial test results illustrated that the nano-silver colloids have excellent antimicrobial effects against E.coli and Streptomyces.
Oxidation Behavior of TiAl Based Alloys Prepared by Spark Plasma Sintering
Authors: Chen Hua , Zhang Jing Chao , Lu X.Y
Published: November 2010

The spark plasma sintering (SPS) microstructure and high temperature oxidation behavior of TiH2-45Al-0.2Si-5Nb(at.%) alloy were investigated.Emphasis was placed on the effect of SPS microstructures, obtained by blend powder and mechanical alloying powder. The mass gain due to oxidation was measured using an electro balance. The oxide layers as well as its micro-structure were examined by SEM and EDS, and XRD. The results show that sintered microstructure of blend powder is composed of fully lamellar TiAl/ Ti3Al phase, and that of the mechanical alloying powder is composed of finer granular TiAl/Ti3Al phase. The latter oxidation rate is lower, and forms continuous mixed oxide layer of Al2O3 and TiO2. Both SPS microstructure of blend powder and mechanical alloying powder are superior in oxidation behavior to ordinary vacuum sintering.
Preparation, Characterization and Magnetic Properties of Fe59Co41 Alloy Nanowires Using AC Electrochemical Deposition
Authors: Wang Xue Hua , Chen Gui , Yang Liang , Li Cheng Yong , Cai Peng
Published: November 2010

Highly ordered Fe59Co41 alloy nanowires with a diameter of about 50 nm and length of about 4.1µm have been fabricated by alternating current (AC) electrodeposition into the anodic aluminum oxide templates. The morphology, structure and magnetic properties of Fe59Co41 alloy nanowires were characterized by TEM, EDS, XRD and VSM, respectively. The results indicate the Fe59Co41 nanowires with a high aspect ratio are very uniform and regular, which corresponds to the diameter of the nanochannel of the AAO membrane. XRD and HRTEM results show that the Fe59Co41 nanowires crystallize in hexagonal-close-packed (HCP) cobalt solid solution with [100] preferred orientation. VSM results show the Fe59Co41 nanowire arrays have a notable perpendicular magnetic anisotropy with easy magnetization axis along the nanowires. The magnetic properties of Fe59Co41 nanowire arrays are mainly predominated by shape anisotropy.
Copper Plating on SUS 304 Plate from Acid Bath
Authors: Chiba Atsushi , Doi Yasunori
Published: November 2010

SUS 304 used. A passive film on surface was needed to remove with anodic electrolytic degreasing in 3.0 mol/dm3 H2SO4 at 298 K. Cu film was electroplated 20 mA/cm2 in 0.5 mol/dm3 CuSO4 and 2 mol /dm3 H2SO4. Current efficiency increased when plating carried in sonication of 28 kHz after plating in stationary state. Particles were destroyed and size became smaller with shockwave pressure. Particles were pressed in pinholes, defects, etc. Surface that was obtained at 28 kHz was smooth and dense compared with other agitation states.
Tribological and Lubrication Properties of Sandblast-Textured Surfaces with Varied Roughness
Authors: Wang Yan Qing , Yang Hai Feng , Han Qing Gong , Fang Liang , Ge Shi Rong
Published: November 2010

Surface roughening, with certain roughness topography, is thought to be as an effective tribological method of decreasing friction coefficient of kinematic pairs. Friction and wear of AISI1045 steel surface roughened by convenient and economical way of sandblasting was investigated under lubrication conditions. Roughened and polished samples run against Φ4mm GCr15 pin lubricated by engine oil were tested in reciprocating mode with different load and speed on UMT- testing machine. It is found that there exists the optima surface roughness (Ra is about 3.92μm) roughened by sandblasting in which the least wettability contact angle between engine oil and textured steel surface is obtained, hence the lowest friction coefficient and wear rate is due to the optima hydrodynamic sliding property, although the sliding surface was not in hydrodynamic lubrication state.
Mathematical Model of Spiral Bevel Gears Manufactured by Generating Line Method
Authors: Yang Zhao Jun , Wang Yan Kun , Li Li Nan , Zhang Xue Cheng
Published: November 2010

Generating line method for designing and manufacturing spiral bevel gears is proposed in this paper. The tooth surface of spiral bevel gears produced by generating line method is formed by exact spherical involutes, the mathematical model to describe tooth surface has been derived based on gear meshing theory and the cutting motion. This study can provide some fundamentals for manufacturing and contact analysis of spherical involutes spiral bevel gears.
Planning and Optimizing of Assembly Production Line Based on Simulation
Authors: Jia Chen Hui , Zhang Shu Tao , Xia Xin Tao
Published: November 2010

Based on optimization theory, computer simulation and Virtual Manufacturing, the framework modeling of Virtual Assembly Production Line planning was built in order to solve its complex optimization. By planning static assembly production line, the static optimization solution can be obtained. Then, dynamic simulation planning of production line was put up in order to analyze and evaluate the capability of production line. Thereby, assembly planning can be improved and optimized more.
Preparation of WC-Low Chromium Cast Iron Composite Material by Cast-Infiltration
Authors: An Ning
Published: November 2010

Use of Low-chromium white cast iron as matrix, WC as reinforcement particles, in conditions of Quartz sand in ordinary water glass dry, non-vacuum, using self-made penetration compound was prepared by WC particles reinforced surface composite material with superior wear resistance, is 2.73 times that of high chromium cast iron composite layer hardness can reach HRC60 or more. Smooth casting surface roughness, dimensional accuracy is more accurate, composite layer and substrate is good.
Study on the Spraying Technique of Ultra-High Strength Parts Made by 30CrMnSiNi2A Steel
Authors: Guo Bi Xin , Li Jian Xia , Gao Yun Kui
Published: November 2010

The oxy-acetylene flame spraying is a new kind of the spraying technology which is developed in recent years. The ultra-high strength is the pivotal structural material in aviation. The oxy-acetylene flame spraying method that is used to mend aeronautic parts made by ultra-high strength steel is studied in this article. The spraying technology of ultra-high strength parts made by 30CrMnSiNi2A steel is introduced.
Optimization of the Hot Pressing Parameters of Nanocomposite Ceramic Tool and Die Materials: I. with BP Neural Network Method
Authors: Zhang Jing Jie , Xu Chong Hai , Yi Ming Dong , Zhang Hui Fa , Wang Xing Hai
Published: November 2010

In this paper, back propagation neural network was used in the optimum design of the hot pressing parameters of an advanced ZrO2/TiB2/Al2O3 nanocomposite ceramic tool and die material. The BP algorithm could set up the relationship well between the hot pressing parameters and mechanical property of nanocomposite ceramic tool and die materials. After analyzed the predicted results, the best predicted results were the sintering temperature was 1420°C and the holding time was 60min. Under these hot pressing parameters, the best flexural strength and the best fracture toughness of the material could be obtained.
Basic Principle and Mathematical Model of Cutting Hypoid Gears by Generating Line Method
Authors: Yang Zhao Jun , Li Li Nan , Wang Yan Kun , Zhang Xue Cheng
Published: November 2010

Generating line method, which is based on the generating process of spherical involute curve, is a new processing theory of cutting ideal spherical involute gears. This paper proposed the geometry and basic principle of cutting hypoid gears by this method, and defined the planar conjugated relationship between generating lines of the pinion and gear. A mathematical model of tooth surfaces is established based on cutting process. This model can be applied to any shapes and parameters of the gear generating line.
Effect of Cryogenic Treatment and Carbide Spray Coating on the Wear Behavior of Carburized Steel
Authors: Chiu Liu Ho , Lin Yi Min , Yeh Shu Hung , Chang Heng
Published: November 2010

This study is to investigate the wear behavior of carburized JIS SNCM 415 Ni-Cr-Mo steel being cryotreated and followed by carbide spray coating for achieving improvement in wear resistance. Comparative specimens of JIS SNCM 439 steel were quenched and tempered to 45HRC to obtain a similar surface condition as the carburized JIS SNCM415 samples. The thickness of WC/Co coatings of 125 μm was deposited with the use of high velocity oxy-fuel (HVOF) process. The microhardness of the WC/Co coatings has been found to achieve 1025±75 HV. A series of wear tests have been carried out on steel samples subjected to various conditions under 95.9N with 180 rpm on a dry block-on-roller tester. From the result of 12 hr wear tests, the mass loss of carburized SNCM 415 steel through cryotreatment was 0.025 g improved from 0.05g of steel without cryotreatment. In addition, the mass loss of carburized SNCM 415 specimen under cryotreatment and HVOF process was further decreased from 0.025 g to 0.002 g. The mass loss of comparative JIS SNCM 439 steel coated by the HVOF process was decreased to 0.002 g from 0.045 g of steel without coating. The results clearly establish that cryotreatment and HVOF process significantly improve the surface hardness and wear resistance of carburized JIS SNCM 415 steel.
Optimization of Process Parameters of Thin Aluminum-Lithium Alloy Sheet Metal Laser Forming Based on Water-Cooling
Authors: Jiang Min Feng , Ding Lei , Zheng Yuan Yuan , Wang Xiao , Liu Hui Xia
Published: November 2010

Laser forming is a new flexible sheet metal forming process. By means of the theory of orthogonal experimental design method, design of experiment and optimization were carried out on thin aluminum-lithium alloy AA2090 sheet metal laser forming under the condition of water-cooling. And through the calculation and analysis of the experiments, the effect of the four process parameters related to the energy of laser beam on bending angle under the condition of water-cooling were ranked in order of laser power, number of scan, scan speed and beam diameter. Furthermore, the optimum process parameters were obtained, and experiment verifications were carried out.
Influence of Vacuum Heat Treatment and Salt-Bath Nitrocarburization on the Corrosion Behavior of JIS SKD61 and DH31S Hot Work Steels
Authors: Yeh Shu Hung , Chiu Liu Ho , Lo Wan Chung , Huang Chien Lung
Published: November 2010

The corrosion behavior of the nitrocarburized JIS SKD61 and DH31S hot work steels has been investigated. The as received JIS SKD61 and DH31S steel was quenched and tempered to obtain the tempered martensitic microstructure. The nitrocarburizing treatment was conducted in a 570°C salt bath for 40, 80, and 120 minutes, respectively. Treated specimens were characterized by means of microstructural analysis, microhardness measurements, X-ray diffraction analysis, glow discharge spectrometer analysis and electrochemical tests in a 3.5wt% NaCl aerated solution. The thickness of compound layer of nitrocarburized specimens was about 1-3μm, and the microhardness is in the range between 790 – 820 HV0.05. The compound layer of the nitrided specimen was consisted of ε-phase (Fe2-3N) and the γ’-phase (Fe4N). The highest corrosion potential (Ecorr) in this study reached to -0.3 V for NC-S80 and NC-H80 specimen, it’s about 1.5 times higher than that of ferrite substrate. There is no evident difference on corrosion current density (Icorr) with prolonging nitrocarburizing treatment for both steels. Nevertheless, the corrosion properties were improved by nitrocarburizing process.
Research on Surface Modification Technique by EDM
Authors: Li Xiao Hai , Fang Yu , Wang Xin Rong , Yin Bao Lin
Published: November 2010

This paper describes a new method of die surface modification by ordinary Electrical Discharge Machining (EDM) tool. First, the principle of this method is studied. Secondly, the technology and characteristics of the die steel coating are discussed in detail based on lots of experiments, and the results show that the die steel characteristics are improved evidently by using EDM. At last, the technology is applied to the punch die initially, and it can be drawn that the life of the coated punch die is improved evidently compared with the non-coated punch die through the punching test.
Analysis and Evaluation for Usability of the Lime Titania Type Structural Steel Covered Electrode
Authors: Wang Yong , Wang Bao , Song Li , Wang Zhi Jun
Published: November 2010

Metal transfer mode of the lime titania type structural steel covered electrode is a mixed one that coexists as the globular short-circuiting transfer, the flux-wall guided transfer, the explosive transfer and the spray transfer. Constitute of the metal transfer modes has a direct effect on usability of the covered electrode. Using the Analysator Hannover, the welding electric parameters are measured and analyzed. Four characteristic information values correlated with usability of the covered electrode are extracted, such as the sum of probability density of the short-circuiting voltage, variation coefficient of the arc voltage, the sum of probability density of the big short-circuiting current and the short-circuiting frequency, and then method of the principal component analysis is applied to determining evaluation index of usability of the covered electrode. Usability of the covered electrode is quantitatively evaluated. It offers a new method for scientifically evaluating usability of the lime titania type structural steel covered electrode.
First-Principles Study on Co-Doped ZnO with Oxygen Vacancy
Authors: Weng Zhen Zhen , Huang Zhi Gao , Lin Wen Xiong
Published: November 2010

The interatomic exchange interactions and the electronic structure of Co-doped ZnO with and without oxygen vacancy have been investigated by the first-principles calculations based on density functional theory. It is found that the oxygen vacancy can strengthen the ferromagnetic exchange interaction between Co atoms and might be available for carrier mediation. The oxygen vacancy near to the Co atoms is more favorable for the ferromagnetic ground state.
Experiment Research on Abrasive Belt Vibration Grinding Terminal Surface of Work Piece
Authors: Leng Yue Feng , Zhang Nina
Published: November 2010

In order to solve the problem of the alloy can not achieve the low surface roughness value in high-temperature, when it is grinded by abrasive disk, so that it can not meet the requirement of the craft. It uses abrasive belt grinding technology,adopts the method of fixed precise belt vibration grinding head on the CA6140 lathe and makes experiment of the impact on roughness of work piece surface from rotational speed of work piece , sand size of abrasive belt, horizontal amount of feed and process time. The result shows that the roughness value can achieve the requirement. It generalized the method of using abrasive belt grinding high- temperature alloy to make the roughness meet the requirement of craft, when guaranteed efficiency.
Effects of Ultrasound Power on Microstructure and Mechanical Properties of AZ91 Alloy
Authors: Wang Zhao Hui , Wang Xu Dong , Zhang Jian Fen , Du Wen Bo
Published: November 2010

Ultrasonic vibration was introduced into the molten AZ91 alloy in this paper. The effects of ultrasound power (from 0 to 900W) on the microstructure and mechanical properties of AZ91 alloy were investigated. The results show that the microstructure, hardness and mechanical properties of the AZ91 alloy have been improved with the ultrasonic treatment. In this work, the mechanical properties of the alloy reached the peak value when the ultrasound power was 600W. Also, the mechanism of ultrasonic vibration in the AZ91 alloy was discussed.
Study of Electro-Hydraulic Force Control System Controlled by Flow Press Servo-Valve and Nonlinear Performance Analysis
Authors: Shao Jun Peng , Li Jian Ying , Wang Zhong Wen , Han Gui Hua
Published: November 2010

The mathematic model of the flow press sever-valve was built in this paper, during the process of building the model, the author took into account the load moment brought by the pair of spray nozzles flow force and the load moment brought by the force couples back pole and the fundamental equation of the force moment motor. On the other hand, the author analyzed the influence of the nonlinear factor to system performance, and the nonlinear factor was valve port overlap length disaccord caused by machining error. The mathematic model of the electro-hydraulic force control system controlled by the flow press servo-valve with valve port error was built. The results of simulation and experiment showed that valve port error badly influenced the system performance, and that valve port error was the main reason of the pressure higher than the supply pressure, which is one of the two cylinder cavities. The simulation curve and the experiment curve were accord compared by system simulation and experiment results, so we can know that the mathematic model of the flow press sever-valve and of the electro-hydraulic force control system controlled by the flow press servo-valve is correct.
Microstructure and Wearability of Surface Coating of Fe-Based Amorphous Core Welding Rod
Authors: Wang Bin , Yang Zhen , Zhou Dong Mei , Zhou Pei Shan
Published: November 2010

Based on the classic formula of J507 coated electrode，the welding rods were prepared by adding Fe41Co7Cr15Mo14C15B6Y2 Fe-based amorphous alloy or HO8A as welding core. The surface coating on Q235 was made by manual electric arc welding with two kinds of welding rods,while Ar2 gas is used to cool the weld layer. The microstructure and wearability of welded joint and the coating layer were investigated by the means of metallographic analysis, SEM,XRD and M-2000 wear tester.The results show that the coating layer is in the amorphous state,and the wearability of surface coating with Fe-based amorphous core welding rod is better than another.
Effect of Mg on the Microstructure and Electrochemical Corrosion Behavior of Arced Sprayed Zn-Al Coating
Authors: Zhu Zi Xin , Liu Yan , Xu Bin Shi
Published: November 2010

Cored wires and high velocity arc spraying technique (HVAS) were used to produce high Mg content Zn-Al-Mg alloy coatings on low carbon steel substrates. The microstructures, mechanical properties and electrochemical corrosion behaviors of the Zn-Al-Mg coatings were investigated comparing with Zn and Zn-Al alloy coatings. And the electrochemical corrosion mechanisms of the coatings were discussed. The coatings show a typical aspect of layered thermal sprayed material structure. Chemical analysis of the coating indicated the composition to be Zn-14.9Al-5.9Mg-3.0O (wt.%). The main phases in the coatings are Zn, Mg2Zn11, Al12Mg17 and MgAl2O4, together with a little Al2O3 and ZnO. The corrosion potential of Zn-Al and Zn-Al-Mg coatings decreased a little and then increased towards the noble potential. With addition of Mg, the corrosion products accumulated to form stable passive film can block off the pores in the Zn-Al-Mg coating, and thus may prevent attack on the underlying steel substrate. The Zn-Al-Mg coatings show higher electrochemical corrosion resistance in salt solution than Zn-Al coatings.
Plasma Electrolytic Carbonitriding of 20CrMnTi Steel
Authors: Fan Xin Min , Huang Jie Wen , Yang Qun , Gan Jun Jie
Published: November 2010

A carbontirided layer was produced on 20CrMnTi steel by plasma electrolytic carbonitriding (PEC/N). Scanning electron microscopy with an energy dispersive X-ray analysis was employed to study the morphology and chemical composition of the carbonitrided layer. Hardness of the layer was measured using a microhardness tester, and the phase structure was determined by X-ray diffraction. The results show that a compact carbonitrided layer can be obtained on the surface of 20CrMnTi steel. The thickness of the layer increases with carbontriding time. When the sample was treated at 120V for 20min, the thickness is 45μm and the highest microhardness is 766HV0.05. The carbontrided layers are composed of Fe3C, Fe5C2, ε-Fe3N and α-Fe.
Numerical Study of the Thermosolutal Convection Induced Macrosegregation during Columnar Solidification
Authors: Hao Jing , Wu Meng Huai , Ludwig Andreas , Grasser Monika
Published: November 2010

As a response to “call for contribution to a numerical problem for 2D columnar solidification of binary alloys” [Bellet et al., Int. J. Therm. Sci., Vol. 48(11)(2009), p. 2013], the macrosegregation in a Pb-18wt.%Sn benchmark casting is numerically studied with a two-phase columnar solidification model developed by the current authors. The studies were done with 2D calculations in response to the call, and a 3D calculation was performed to confirm the consistency with the 2D case. A grid-sensitivity study was done to ensure the reliability and accuracy of the present results. The segregation mechanism due to thermosolutal convection was analyzed and the uncertainties resulting from the inaccurate thermophysical properties, modelling and process parameters are discussed. The numerical model was evaluated by comparison with experiments.
The Steel Joint Life of the Single-Wheeled Cycle Using FEM Analysis
Authors: Wang Hai Yang , Li Shu Hua , Li Li Xia , Zha Xiao Xiong
Published: November 2010

The single-wheeled cycle is fashion and convenient, but there are some problems when used, especially the joint that connect to the lead bicycle. Due to the unavoidably collision when using, there will be the cause on joint parts with high stress state of frequent change, which makes the single-wheeled cycle under security problem. In order to get it fully, this paper use the FEM software to model the single-wheeled cycle. Under the different acceleration exert, the stress state of the joint and stress distribution are researched, then recommendations given about the potential safety hazard, joint life, and the suggestions for improvement.
Finite Element Thermal-Mechanical Coupled Analysis of Strand Bulging Deformation in Continuous Casting
Authors: Zhang Jia , Shen Hou Fa , Huang Tian You
Published: November 2010

In order to reduce the internal cracks and control the quality of the steel strand in continuous casting, a thermal-mechanical model considering the movement of the strand, real roll arrangement and caster structure, has been established with the elasto-viscoplastic constitution to predict the three dimensional temperature distribution and bulging deformation of the strand. Using the sequentially coupled finite element method the model is solved numerically, and is validated by the comparisons of the simulation results and measured data. The model is suitable for future research on the whole strand bulging deformation to help improve the strand quality in continuous casting.
Effect of Graded Bias on Microstructure and Hardness of CrNX Films
Authors: Tan Shu Yong , Zhang Xu Hai , Wu Xiang Jun , Fang Feng
Published: November 2010

CrNx films were synthesized under graded/constant bias by DC magnetron sputtering. In the present work, the graded bias deposited CrNx films have both (111) and (200) orientations while only (111) orientation in low bias (-20 V) and (200) orientation in high bias (-200 V). Both the magnitude of bias and preferred orientation result in the variation in their surface morphology from pyramidal (loosen) to cellular (dense) structure. The hardness of the graded films is between the low and high constant bias ones. The relationship between the hardness and bias gradient is similar with the relationship of hardness and the content of (200) preferred crystallites, which implies the fine (200) preferred crystallites is an important factor for hardness of graded bias films.
Simulation Analysis of Pneumatic on-off Pressure Mechanism on Printing Press
Authors: Guo Jun Zhong , Yang Jun Ping
Published: November 2010

The on-off pressure mechanism has an important function to the printing press, the quality of which concerns the working performance of the printing machine and the quality of printed products directly. In this paper, the pneumatic on-off pressure mechanism is discussed; the work demand of order on-off pressure is analyzed. In addition, the three-dimensional digital model and the kinematic analysis process can be achieved on the basis of ADAMS software. What’s more, the on pressure value in the process of on pressure is derived from the kinematic analysis. Lastly, the relation between the motion of on-off pressure mechanism and cylinder’s angular displacement is analyzed, an important basis to the on-off pressure mechanism’s optimal design will be provided.
Single Step of Binder Thermal Debinding and Sintering of Injection Moulded 316L Stainless Steel
Authors: Almanar Indra Putra , Hussain Zuhailawati , Omar Mohd Afian
Published: November 2010

Metal injection moulding was performed with gas atomized 316L stainless steel powders. Feedstocks were prepared using a paraffin wax/polyethylene/stearic acid binder system and subsequently molded into tensile bar specimens. Solvent extraction done at 80○C has shortened the debinding process to 30 minute. Single step of thermal binder debinding and sintering was done in a vacuum furnace. Sintering at 1380○C has reduced the porosity and associated with grain growth that result in an increase in ultimate tensile strength to 444 MPa while the elongation increased to 29% before fracture.
Research on the Process of Reaming Ultra-Long Cylinder
Authors: Feng Shuan Liang , Liu Zhen Yong , Yang Mei , Sun Hong Qiang
Published: November 2010

This article describes the overall processing technology of the ultra-long cylinder, especially the internal pull the hinge hole processing technology from the tooling, cutting tools to machining parameters are introduced in detail to solve the difficult problem of processing very long hole, cylinder machining accuracy is guaranteed.
Research on Tempering Experiment for Laser Phase Transformation-Hardening Specimen
Authors: Liu An  Zhong , Yan Yan , Zhang Su , Cui Jian Hua
Published: November 2010

In this paper, the specimens of GCr15 steel were quenched by laser transformation hardening experiment and then they were tempered at different temperatures. The tempering micromorphology and microstructure of laser surface hardening layer were studied, and the photos of scanning electric microscope(SEM) were used in the fractal analysis. The relationship between the tempered temperatures and the hardness of the hardening layer surface was researched, and the relationship between the hardness of the hardening layer surface and the fractal dimension of the surface hardening layer SEM photos was also researched.
Contact Simulation of Thrust Ball Bearing Based on ANSYS
Authors: Gao Ji , Zhang Rui
Published: November 2010

The contact shape, size and stress of thrust ball bearings are simulated with taking 1/13 part of bearing as finite element model, neglecting the influence of cage and lubrication, imitating the boundary curve with high order element, meshing the top and bottom raceways with sweep and the ball with free meshed by finite element software ANSYS in the contact area for the effective and exact designing of thrust ball bearing. The simulation results are corresponded to the results of Hertz’s contact theory. There are less margins for error between main dimensions except the shortest axis of an ellipse. More important will be obtained from the simulation on finite element software which cannot be derived from the traditional theory. It could improve the designing efficiency of thrust ball bearing.
Investigation on the Structure and Properties of TiAlN Coatings Deposited by DC Reactive Magnetron Sputtering
Authors: Wang Xuan , Zhang Kui , Yue Guang Hui , Peng Dong Liang , Qi Zheng Bing , Wang Zhou Cheng
Published: November 2010

TiAlN coatings have been deposited by reactive magnetron sputtering from TiAl alloy target using a direct current (DC) power source. The crystal structure, chemical composition, surface morphology and hardness of TiAlN coatings which were prepared at various N2 flow rates have been systemically investigated. The results show a strong effect of N2 flow rates on the orientation, grain size and densification in TiAlN coatings. The TiAlN coating shows the highest hardness at a certain N2 flow rate when it has the most compact structure.
Phase-Field Simulation of Process in Sintering Ceramics
Authors: Liu Liang Liang , Gao Feng , Li Bo , Hu Guo Xin
Published: November 2010

A phase field model is used to describe the microstructural development during the ceramic sintering. The evolution of the density is governed by Cahn-Hilliard equation, while the long-range order (lro) parameter fields by the time-dependent Ginzburg-Landau equation. In the simulation, green microstructures that consist of circular particles with different particle-size distributions and green densities have been produced by the stochastic growth model. The porosity of 25.6% was considered. The formation and growth of sintering neck, the seal, spheroidization as well as disappearance of pores and growth of grains are observed during simulation. The simulation results show grain boundary diffusion and surface diffusion are the dominate mechanism at the initial sintering stage. The predicted growth exponent of sintering neck and grain is consistent with the existing theoretical analysis.
Effects of Carbon Concentration Variation on Primary Austenite Stability of High Chromium Cast Iron
Authors: Ma You Ping , Li Xiu Lan , Yang Lei
Published: November 2010

The effect of carbon content on primary austenite stability of high chromium white cast iron(15.0wt.%) was investigated by means of optical microscopy(OM) and energy spectrum spectrometry(EDS).The results indicate that with increasing the concentration of carbon,the carbon of solid solution in the primary austenite increased, while the chromium was on the contrary, The increase of carbon content stabilized primary austenite under the condition that no secondary carbides precipitated, however, once secondary carbides precipitated, the stability of primary austenite deteriorated with the increase of carbon contents. 2.63wt.% C was the critical value of the secondary carbides precipitation in high chromium white cast iron(15.0wt.%).
Creep Fracture Analysis of W Strengthened 9% Cr Steel Weldment
Authors: Wang Xue , Pan Qian Gang , Liu Zi Jun , Zeng Hui Qiang , Tao Yong Shun
Published: November 2010

The creep rupture behaviour,hardness distribution and microstructure of weldment made by submerge arc welding for W strengthened P92 steel are described in this paper. The cross-weld creep tests were carried out at 923K under stresses in the ranges 130-100MPa. For stress below 120MPa, weld-joints were ruptured by the Type crack, which located in their fine-grained heat affected zone(FGHAZ)with the smallest measured cross-weld hardness. A strong drop in creep rupture strength of weldment was induced by brittle type failure. In addition to coarsening of M23C6 carbides and an equiaxed fine grains in FGHAZ, intermetallic Fe2(Mo,W)Laves phase precipitated on grain boundaries during creep is probably the significant factor caused the type failure.
Research on Focusing Spot Shape of High Power CO2 Laser
Authors: Shang Xiao Feng
Published: November 2010

In order to meet the requirements of laser processing technology and quality, the laser bean oblique incidence technique is put forward and focusing laser spots with different shape and incident direction are realized. The relation between the output laser beam spot shape and laser power of high power CO2 laser is studied through the organic glass sampling method. The result indicates that the laser beam cross-section shape presents rectangle and the long-axis length of laser beam has nothing to do with the laser power changes, but the short-axis width increases with the laser power improving. The two-dimension rotary laser head is designed and the laser bean tilt incidence is realized. The formula of the relation between focusing spot coordinate in the processing plane and laser head turn angle, also swinging angle is deduced. The relation between the focusing spot shape and the laser power, defocusing amount, laser head turn and swinging angles is researched through the single-side gummed paper sampling method. The result indicates that the focusing laser spot form is affected by the parameters of laser power, defocusing amount, laser head turn and swinging angles.