bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of Surface Roughness Profiles for Milling Process with Fractal Parameters Based on LS-SVM
Authors: Gan Ben , Huang Yi Jian , Zheng Gui Xia
Published: March 2010

Least squares support vector machines (LS-SVM) were developed for the analysis and prediction of the relationship between the cutting conditions and the corresponding fractal parameters of machined surfaces in face milling operation. These models can help manufacturers to determine the appropriate cutting conditions, in order to achieve specific surface roughness profile geometry, and hence achieve the desired tribological performance (e.g. friction and wear) between the contacting surfaces. The input parameters of the LS-SVM are the cutting parameters: rotational speed, feed, depth of milling. The output parameters of the LS-SVM are the corresponding calculated fractal parameters: fractal dimension D and vertical scaling parameter G. The LS-SVM were utilized successfully for training and predicting the fractal parameters D and G in face milling operations. Moreover, Weierstrass-Mandelbrot（W–M ）fractal function was integrated with the LS-SVM in order to generate an artificially fractal predicted profiles at different milling conditions. The predicted profiles were found statistically similar to the actual measured profiles of test specimens and there is a relationship between the scale-independent fractal coefficients(D and G).
Structural, Optical and Electronic Properties of Cu-Doped ZnO Films Synthesized by RF Magnetron Sputtering
Authors: Wu Zhao Feng , Xu Qin Yan , Wu Xue Mei , Zhuge Lan Jian , Hong Bo , Chen Qiang
Published: March 2010

Zn1-xCuxO films were prepared by radio frequency (RF) magnetron sputtering method. The wurtzite ZnO crystal can be well retained up to a Cu composition of 10% and doped Cu ions substituted into Zn sites of ZnO host lattice. All the samples show high transparency over the wavelengths from 400 to 1000 nm. The room temperature (RT) resistivity shows an increase in Mn doping samples, which indicates that the doped element is at the status of deep donor levels. The decrease in the bandgap in Cu doped ZnO films rather than in pure ZnO film indicates that there are impurity bands created by Cu 3d orbital or strong d-p coupling between Cu and O in our samples. In addition, photoluminescence (PL) spectra show UV emission at ~3.19 eV shifts to lower energy side with Cu doping, indicating the possibility of band-gap engineering in Zn1-xCuxO films.
Effect of Non-Steady State Loading on Rolling-Sliding Contact Stress
Authors: Guo Jun , Jin Xue Song , Wen Ze Feng , Liu Qi Yue
Published: March 2010

The stresses, strains, and deformations produced by repeated, two-dimensional non-steady state rolling-sliding contact were analyzed using an elastic-plastic finite element model. An advanced cyclic plasticity model was used. The non-steady state rolling contact was restricted to a harmonic variation of the normal Herztian contact pressure. Repeated rolling and sliding were simulated by multiple translations of a set of varying normal and tangential surface tractions across an elastic-plastic semi-infinite half space. The non-steady state loading considered results in a wavy contact surface profile. The surface displacements and wave depth of the wavy deformation increase with increasing rolling passes, but the increases in wave depth per rolling pass (ratchetting rate) decay. The residual stresses and strains near the wave trough of the residual wavy deformation are higher than those near the wave crest. The results are in agreement with the experimental observations. The tangential force has a greater influence on the residual strains than on the residual stresses.
Debonding Analysis along a Softening FRP-Concrete Interface between Two Adjacent Cracks in Plated Beams
Authors: Qu Hong Chang , Zhang Peng
Published: March 2010

External bonding of fibre reinforced polymer (FRP) composites has become a common way for strengthening concrete members. The performance of the interface between FRP and concrete is one of the key factors affecting the behaviour of the strengthened structure. For this FRP-concrete structure, there are two types of debonding failures: plate end debonding and intermediate crack (IC) induced debonding. This paper presents an analytical solution for the second type debonding failures in FRP-concrete bonded joint model where the FRP plate is subject to tension at both ends. Both the strengthened beam and strengthening FRP are modeled as two linearly elastic Euler–Bernoulli beams bonded together through a thin adhesive layer. The debonding process of the FRP–concrete interface is discussed in detail, and closed-form solutions of bond slip, interface shear stress, and axial force of FRP in different stages are obtained. Parametric studies are further carried out to investigate the effect of the thickness of adhesive layer on the bond behavior of FRP–concrete interface.
Research of Contact Pressure of an Elastoplastic Rough Body in Contact with a Smooth Rigid Plane
Authors: Huang Jian Meng , Gao Cheng Hui
Published: March 2010

A thermo-mechanical coupling model for the rough surface is established. The model considers friction contact between a rigid flat plane and a rough surface based on 3D fractal theory and allows the analysis of the effects of elastic-plastic deformation of rough body and the interplay among asperities. The contact pressure distribution for the static state beneath different loading mode and for the dynamic state in the presence of the frictional heat flux is found. The results show the fluctuation of the average contact pressure during the process of loading is related to the velocity of loading. The synthetical function of multiple factors such as the thermal deformation, the rising temperature, the interaction between asperities makes the complicated relationships among the maximum temperature, the maximum contact pressure and the real contact area.
A Study on Diffusion in Hot-Dip Aluminizing
Authors: Lu Yu Heng , Qi Shang Guan , Huang Cai Min , Pan Jie Hua , Zeng Jian Min
Published: March 2010

Hot-dip aluminizing panels of Q235 steels were produced in laboratory. Then the hot-dip aluminizing samples were executed diffusion at elevated temperatures protecting with flowing argon gas. Metallographic microscope, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were employed for compositional analyses and graphical analyses of coating. The diffusion process was researched and the phase’s microstructure after diffusion was analyzed and discussed. The hot-dip aluminizing diffusion mathematical model was established with the finite element method. The results show that after diffusion in hot-dip aluminizing, the aluminum of the coating disappeared. The thickness of diffusion layer increased and the dentate frame disappeared. There are some iron-rich phases such as Fe2Al5, FeAl and Fe3Al in the diffusion layer. The phase Fe2Al5 decreases and the phase FeAl increases. The mathematical model corresponds with the actual situation. The diffusion coefficients of Al atoms diffusing in intermetallic compounds were calculated at 950°C, which were 0.29×10-12 m2/s for Fe2Al5, 0.7×10-12 m2/s for FeAl, and 0.27×10-12 m2/s for Fe3Al, respectively.
Experimental Study on Surface Roughness and Residual Stress by End Milling 69111-Stainless Steel
Authors: Yuan Rong Hua , Sun Jie , Li Jian Feng , Song Liang Yu , Zhang Yong Wu
Published: March 2010

69111-stainless steel has wide applications in aerospace industry due to its comprehensive performance. However, its machining properties are not well studied due to the short using history in product components. In this study, a series of end milling experiments were conducted to characterize surface integrity at various milling conditions. The experimental results have shown that the milled surface roughness value increases with increased feed and cutting speed, while decrease with axial depth-of-cut (DoC) , and presents an inflexion with the radial DoC, with a rang of 0.7~1.7μm. Residual stress determined by the coupling effect of mechanical and thermal deformations varies differently with the increased cutting parameters.
New Methodologies for the Determination of Precise Forming Limit Curve in Single Point Incremental Forming Process
Authors: Hussain Ghulam , Lin Gao , Hayat Nasir , Dar Nameem Ullah , Iqbal Asif
Published: March 2010

Straight groove test is a widely-used formability test in Single Point Incremental Forming (SPIF). This test does not cover all the forming aspects of SPIF process, however. In order to ascertain its legitimacy, two new tests covering necessary SPIF aspects are devised. The FLC of an aluminum sheet is determined using the newly proposed and straight groove tests. It is found that the straight groove test shows much lower formability than the new tests. Therefore, the employment of newly devised test(s) is proposed for the determination of precise formability limits.
A Three-dimensional Finite Element Method for Surface Effects
Authors: Chen Xiao Liang , Lin Shun Hong , Ding Jian Ping
Published: March 2010

Due to the relatively high surface-to-volume ratio, the surface effect can be significant for nanoscale materials. A numerical method, which combines surface energy and three-dimensional (3-D) finite element analysis, is proposed to simulate the elastic and plastic deformation of materials and structures at nanoscale. To demonstrate the method is valid and efficient, the free relaxation of single crystalline Cu nanowires is investigated and the numerical results are compared to the atomic simulation results.
Characteristics of Fretting Wear in a Press-Fitted Shaft Subjected to Bending Load
Authors: Lee Dong Hyung , Kwon Seok Jin , You Won Hee
Published: March 2010

This paper presents the results of an experimental investigation of fretting wear characteristics on the contact surface of press-fitted shaft subjected to a cyclic bending load. A series of interrupted fretting wear tests with press-fitted specimens were carried out by using a rotating bending fatigue test machine. The evolution of contact surface profile of press-fitted shaft due to fretting wear were measured with a profilometer. The local wear coefficient during the running-in period is discussed from experimental results and FE analysis. It is found that the maximum depth of fretting wear by repeated slip between shaft and boss occurred at the close of contact edge at the early stage of fatigue life and the regions of worn surface are expanded to the inner side of contact edge as increasing number of fatigue cycles. The initial fretting wear rate at the early stage of fatigue life increased rapidly at all loading condition. After steep increasing, the increase of wear rate is nearly constant in the low bending load condition. The local wear coefficient in running-in period decrease dramatically at the early stage of fretting wear.
Wavelets-Based Feature Extraction for Texture Classification
Authors: Yu Gang , Lin Ying Zi , Kamarthi Sagar
Published: March 2010

Texture classification is a necessary task in a wider variety of application areas such as manufacturing, textiles, and medicine. In this paper, we propose a novel wavelet-based feature extraction method for robust, scale invariant and rotation invariant texture classification. The method divides the 2-D wavelet coefficient matrices into 2-D clusters and then computes features from the energies inherent in these clusters. The features that contain the information effective for classifying texture images are computed from the energy content of the clusters, and these feature vectors are input to a neural network for texture classification. The results show that the discrimination performance obtained with the proposed cluster-based feature extraction method is superior to that obtained using conventional feature extraction methods, and robust to the rotation and scale invariant texture classification.
Experimental Study on Fracture Behavior of UHTCC Overlay/Concrete Interfaces under Mixed-Mode Loading
Authors: Wang Bing , Dai Jian Guo , Xu Shi Lang
Published: March 2010

Four-point bending tests are conducted on fiber reinforced cementitious composites (FRCC) overlaid concrete beams with a “T” notch. The objective is to evaluate the fracture behavior of the interface between the FRCC and the concrete substrates. Two types of FRCC overlays are prepared including a traditional steel fiber reinforced concrete (SFRC) composite and an ultra high toughness cementitious composite (UHTCC), which has a very high tensile strain capacity. All two types of FRCC are prepared in two forms: cast on-situ and prefabricated. Test results indicate that, in comparison with others, the prefabricated UHTCC overlay system has exhibited most desirable behavior in terms of the energy absorption in the interface as well as the crack distributions in the overlay, and therefore has a great potential for use in repair of concrete structures.
Research on the Effects of Atomization on Different Liquid Dielectrics in a High Voltage Electrostatic Field
Authors: Wang Zhao Hui , Liao Zhen Fang , Gao Quan Jie
Published: March 2010

The movements of liquids in the jet area, the transient area and the atomization area were analyzed in a high voltage electrostatic field and the parenchyma of charged liquid drops atomization in these areas were discussed. Experimental equipment, by which the high voltage electrostatic field can be built, has been designed, and the atomization processes of kerosene, emulsifier and alcohol in a high voltage electrostatic field have been studied. The results show that a threshold voltage is needed in order to break up the liquid drops. The lower surface tension and the lower viscous force of liquid, and the higher electrical conductivity ratio, correspond with better electrostatic atomization effects. For kerosene, emulsifier and alcohol, the best atomization effects have been achieved at 40kV, 10kV and 25kV respectively.
Effects of Voltage on the Characteristics and Corrosion Resistance of Microarc Oxidation Coatings on Ti6Al4V Alloy
Authors: Hu Zong Chun , Xie Fa Qin , Wu Xiang Qing
Published: March 2010

Ceramic coatings were prepared on Ti6Al4V in aluminate-based electrolyte by microarc oxidation at various voltages using potentiostatic regime. The phase composition, microstructure and morphology of the coatings were characterized by eddy thickness gauge, XRD and SEM respectively. The corrosion resistance of the coatings was investigated by polarization curve and electrochemical impedance spectroscopy (EIS) in 3.5% NaCl aqueous solution. The results show that all the coatings are mainly composed of Al2TiO5. When the voltage increases from 360V to 510V, the coating thickness grows significantly, and the pores in the coatings get large and deep simultaneously. As a result, the corrosion resistance of the coatings increases first and then decreases with the turning point of 410V, at which the coating prepared shows the smallest corrosion current density of 1.965E-9 A/cm2. The coating prepared at a higher voltage before the discharges grow large and intense (410V in this work) shows the best corrosion resistance.
Effect of WC Grain Size on the Abrasive Wear Resistance of HVOF Spraying WC-Co Coatings
Authors: Li Ming , Yang Yue , Chen Hui
Published: March 2010

Three different WC grain size powder were used to prepare WC-Co coatings employing HVOF technique. The effect of WC grain size on the abrasive wear resistance and failure mechanism were analyzed. The results show that the abrasive wear resistance increases with the decrease of WC grain size. Nanostructured coating is high in surface plasticity. It can only be pressed out of prints, the opportunity of cutting is small. Micro-cutting wear dominates the main abrasive wear mechanism of nanostructured coating.
Nanostructured Surface Layers In Low Carbon Steel and Pure Titanium Induced By High-Speed Rotating Wire-Wheel Deformation
Authors: Fan Xin Min , Liu Fei Yan , Huang Jie Wen
Published: March 2010

A nanostructure surface layer was produced on low carbon steel and commercially pure titanium using high-speed rotating wire-wheel deformation (HRWD). The microstructural features of the surface layer were systematically characterized by cross-sectional optical microcopy observations, transmission electron microscopy, and microhadness measurement was conducted along the depth from top surface layer to matrix of the samples. The results show that nearly equiaxed nanocrystalline layer is formed on the surface of the low carbon steel and pure titanium, in which the average grain size is about 8 nm and 15 nm respectively. The microhardness of the top surface is enhanced obviously compared with that of the coarse-grained matrix.
Tribological Behavior of Molybdenum Alloying Layer on H13 Steel by Electrospark Deposition Technique
Authors: Feng Hong , Tian Lin Hai , Ma Yong , Tang Bin
Published: March 2010

Molybdenum alloying or modified layer was fabricated on the H13 steel substrate by electronic spark deposition technique (EDS). The microstructure, element distribution and microhardness of the modified layer were analyzed using metalloscope, X-ray diffraction (XRD), Glow Discharge Optical Emission Spectroscopy (GDOES) and microhardness tester, respectively. The modified layer is composed of white layer, diffuse layer and heat affected zone. The interdiffusion between Mo element and other elements in H13 substrate results in Metallurgical bonding. Microhardness of the coating is 1482HK0.025 which is 5 times higher than that of H13 steel base (280HK0.025). The ball-on-disc dry sliding test indicates that the friction coefficient of H13 substrate is decreased obviously by the molybdenum modified layer. The wear mass loss of Mo modified H13 substrate is only one seventh of that of the substrate. The wear resistance of H13 is improved significantly by the Mo modified layer.
Sherardizing and Characteristic of Zinc Protective Coating on High-Strength Steel Bridge Cable Wires
Authors: Jiang Jing Hua , Ma Ai Bin , Fan Xin Du , Gong Ming Zi , Zhang Liu Yan
Published: March 2010

Zinc protective coatings on high carbon SWRH82B-1 steel were sherardized to markedly improve corrosion resistance of the high-strength steel bridge cable wires (SBCW). Sherardizing parameters have been optimized by optical microscopy (OM) /scanning electron microscopy (SEM), X-ray diffraction (XRD) and potentiodynamic polarization tests. The sherardizing coatings are composed of the loose outer layer (§-FeZn13 phase) and the dense inner layer (δ- FeZn7 phase) with higher hardness. Addition of Y2O3 activator slightly increases the corrosion resistance of sherardized steel wire in comparison with CeO2. A thicker coating corresponds to a higher sherardizing temperature or a longer heating duration, but an extra thick coating is unfavorable for thru-microcrack existed in the inner layer. Good quality of sherardized wires ( higher corrosion resistance and longer duration than conditional hot-dip-galvanized one) can be produced with the zinc-rich powder containing 7.5wt.% CeO2 activator and 25wt. % SiO2 filler under 400°Cfor 6h.
Enhancing Steam Oxidation Resistance of Ferritic Steels through Formation of Nickel Aluminide Diffusion Coatings at Low Temperatures
Authors: Xiang Zhi Dong , Rose S.R. , Datta Psantu K.
Published: March 2010

A nickel aluminide coating was formed on P92 steel substrate using a two step process of electro-Ni plating followed by pack aluminising at 650 °C. The coating was tested in 100% steam to assess its resistance against steam oxidation at 650 °C using a purpose-built rig for steam oxidation tests. The data obtained were compared with those measured from air oxidation test at the same temperature. It was revealed that steam is a more severe oxidising environment than air for the coating. Oxidation kinetics and degradation mechanisms affecting the lifetime of the coating were discussed.
Synthesis and Characterization of NiCoFeCrAl3 High Entropy Alloy Coating by Laser Cladding
Authors: Zhang Hui , He Yi Zhu , Pan Ye , He Yin Sheng , Shin Kee Sam
Published: March 2010

The NiCoFeCrAl3 high entropy alloy coating with a little addition of C, Si, Mn, Mo has been succesively synthesized by laser cladding. The results show that simple solution phases of ordered BCC and a small fraction of FCC are obtained with fine equaixed dendrites morphology. Because the fine grain strengthening obtained by rapid solidification and the additived small atomic elements like C, Si further increase the distortion of the solid solution lattice, The microhardness of the coating reached above 800 HV and is 50 % higher than previous study on the similar composition by arc melting technique.
Optical and Mechanical Properties of Silver Film on Glass Substrate
Authors: Her Shiuh Chuan , Wang Yi Hsia
Published: March 2010

Silver films were prepared on the glass substrate by electron-beam vapor deposition. The reflectivity of the Ag thin film was measured by a Perkin-Elmer Lambda spectrophotometer in the wavelength region of 450-680 nm. The experimental measurements of reflectivity were validated with the numerical results using the Essential Macleod software. The surface topology and microstructure of the film were examined by means of atomic force microscope (AFM). The effects of the thermal and humidity on the reflectivity of the Ag film were examined by the environmental test. Nanoindentation tests were employed to determine the hardness of the film. The measured hardness of the Ag thin film was found to depend on the penetration depth.
The Optical Properties of Sputtered ZnO Films
Authors: Huang Bo , He Guan Nan , Yang Hui Dong
Published: March 2010

The ZnO films were deposited on quartz glass substrate by RF magnetron sputtering. The ZnO films are highly c-axis oriented with the (002) plane parallel to the substrate. The grains size estimated by the XRD diffraction rises with increase in the Ar/O2 ratio. The optical absorption edge and the near absorption edge characteristics of ZnO films have also been investigated. The optical band gaps of the films have been evaluated from the absorption coefficient of ZnO films. It is found that the value of the optical band gap varys from 3.26 eV to 3.32 eV due to the energy gap enhancement induced by quantum confinement. This variation of band gap can be explained with the theory developed by Brus. For all the films, the absorption coefficient shows the Urbach exponential dependence in the near band edge regime. It is also observed that the value E0 decreases with the Ar/O2 ratio increasing.
Cu-Ni-Ti Composite Diffusion Coating of the Al2O3 Ceramic Surface and its Joining Mechanism
Authors: Zhang Hong Xia , Wang Wen Xian , Wei Yin Hui
Published: March 2010

Al2O3 ceramic surface was metallized using multi-ionic composite coating technology. The obtained Cu-Ni-Ti composite coating was examined and evaluated by energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffusion (XRD) and sound emissive scratch test (SEST). The composite coating composition, the element distribution, the phase structure of the deposited coating, and the jointing mechanism of the deposited coating/ceramics were analyzed. It was found that the obtained alloy coating layer contained elements such as Cu, Ti, Ni and Fe, etc, and no element segregation was observed. XRD result showed that the diffusion coating alloy layer was composed of CuTi2, Ni[TiO3] and Al2O3. Sound emissive scratch test (SEST) results revealed a good adhesion between the diffusion coating alloy layer and ceramic, and no spallation occurred under the maximum load of 100N.
Study on Work Hardening Performance of Pure Shearing Fine-Blanking with Negative Clearance for ASTM-Gr.D and ASTM-1022 Steel
Authors: Li J.H. , Fan W.F. , Zhang Zhong Mei
Published: March 2010

In the process of blanking, the work hardening capability of material possesses very important significance. It not only affects the internal stress value of distorting material, the distribution of stress and the value of blanking force, but also blanking deforming limit and quality of blanked work piece. This paper carries through pure shearing fine-blanking processing experiment with negative clearance for the ASTM-Gr.D and ASTM-1022 steel as well as the micro hardness of the sheared surface for the blanked work pieces in breadthways and lengthways direction measured by Vickers-micro hardness instrument (MH-6). Mechanism of work hardening for fine-blanking with negative clearance is discussed. Meanwhile, the work hardening capability of blanked work piece is analyzed. The work hardening degree of the materials possessing different hardening index is compared. It could be concluded that the work hardening degree of the blanking work pieces was strengthened evidently by the fine-blanking with negative clearance. The hardening layer of blanking fracture could enhance structure intensity and wear resistance of blanking work piece evidently. Therefore, it could improve fatigue strength and the working life of work piece greatly.
Preparation and Properties of the Ni3P-TiO2 Coating on Carbon Steel
Authors: Qiao Ning , Yu Jun , Wei Gang
Published: March 2010

In order to solve the environment problem caused by the inhibitors that are widely used to improve the corrosion and scaling of the carbon steel pipes and equipment in the transportation of the industrial water, the design of using coatings or films on carbon steel is put forward without adding inhibitor. Based on this design, the Ni3P-TiO2 coatings have been prepared on carbon steel by chemical plating and sol–gel method. The coatings mainly compose of Ni3P and TiO2 analyzed by the XRD patterns. The microstructure and morphology of the Ni3P-TiO2 coatings are full, smooth and no cracks using a scanning electron microscopy. The properties of the Ni3P-TiO2 coatings are determined through the electrochemical experiment, scaling inhibition and antibiosis experiment. The results demonstrate that the coatings have the excellent properties of anticorrosion, scaling inhibition and antibiosis. The mechanism of the efficiency maybe due to the change of the interfacial energy, but it need prove through the farther examination.
Influence of Rare Earth on the Properties of H13 Steel by the QPQ Salt-Bath Treatment
Authors: Xiong Guang Yao , Zhao Ming Juan , Zhao Long Zhi , Jian Zhang
Published: March 2010

The structure and properties of H13 steel treated by the QPQ Salt-bath treatment with different content of Rare Earth (RE) LaCO3 were studied. The surface of H13 steel was treated using this method. The microstructure and depth of the treated surface for the steel were analyzed using SEM. The sliding wear resistance was tested on the M-2000 tester and the micro-hardness was tested using 401MVA microscopy hardness tester. The results showed that the thickness and the wear resistance and the speed of nitriding was highly improved and the performance of nitriding layer and the nitriding structure was improved.
The Process of Electroless Plating Ni on the Surface of Carbon Fibers
Authors: Xu Xian Feng , Xiao Peng , Sun Jia
Published: March 2010

Carbon fibers had been modified by the method of electroless plating Ni. The surface morphology, ingredient and cross-section images of modification carbon fibers were charactered by scanning electron microscope and X-ray diffraction. A continuous dense Ni-P alloy layer could be coated on the surface of carbon fibers by such method. The nickel-plated layer expanded in a layer growth pattern. The reaction thermodynamic analysis indicated that the process was spontaneous. The controlling process of electroless plating Ni on the carbon fibers could be divided into 3 stages: at first, controlled by chemical reaction; hereafter, controlled by chemical reaction and ions diffusion; finally, controlled by ions diffusion.
Microstructure and Corrosion Resistance of Free-Sprayed Ni60 Coating Prepared by High Frequency Induction Heating
Authors: Zhang Hong Xia , Luo Cheng , Zhao Hong Li , Feng Guang
Published: March 2010

In order to improve corrosion resistance of widely used carbon steels, self-fusion Ni60 alloys coating was prepared by free-spraying and induction heating, taking 45 steel as substrate. The microstructure and corrosion resistance of the coating and the elements diffusion cross the interface between the coatings and the substrate were analyzed. The results indicate that Ni60 coating free from cracks is obtained by free spraying and induction heating. The microstructure of the Ni60 coated substrate consists of top surface, intermediate layer, dendritic crystal zone and lamellar zone from outside to inside. The corrosion resistance of Ni60 coatings is markedly superior to that of the substrate in acid and alkali solution, and surpasses stainless steel in reductive and alkali solutions
The Progress of Fixed Abrasive Wire Saws in the Last Decade
Authors: Yao Chun Yan , Wang Ming Huan , Peng Wei
Published: March 2010

Diamond wire saw is the leading technology for use in slicing hard brittle material. This paper provides a brief review of its research progress in the most recent years. According to the bonding material kinds of diamond wire saw, it can be classified into three main categories, i.e. metallic bonding materials, organic bonding materials, and resin bonding materials. In the past decade, several new major technical developments in fixed abrasive diamond wire saw have emerged. This paper investigates the related literature on four different types of fixed abrasive diamond wire saws, presents their manufacturing processes and machining performance, and compares the tension and anti-abrasion of the wire saws, removal efficiency of slicing, and their applications in silicon slicing.
Investigation of Nano Composite Coating on Aluminum Alloys Treated by Plasma Transferred Arc
Authors: Qian Shi Qiang , Wang Wei
Published: March 2010

Using a combination of high speed jet electrodeposition and plasma transferred arc (PTA) quenching, a nano-TiN/Ni composite coating on 7005 aluminium alloy can be produced. The microstructure, microhardness, friction coefficient and corrosion potential Ecorr of PTA treated specimens were investigated. The results showed that a rapidly solidified microstructure consisting of the uniformly distributed TiN phase and fine Al3Ni2 intermetallic phase was in PTA treated specimens. The results also showed that the composite coating PTA treated has an average microhardness of approximately 800 HV. The friction coefficient of PTA treated specimens (oscillated around 0.25) is considerably lower than that of TiN/Ni composite coating (oscillated around 0.35). The PTA treated specimen had the lowest corrosion current density Icorr as well as the highest corrosion potential Ecorr and showed an improved corrosion resistance compared to 7005 aluminium alloy as well as TiN/Ni composite coating.
High Temperature Wear Behaviors of Electro-Brush Plating Ni-P Coatings
Authors: Li Zhi Ming , Qian Shi Qiang , Wang Wei , Shen Hong Wei , Long He Sun
Published: March 2010

This paper have studied the high temperature frictional wear properties of Ni-P coatings on 20CrMo steel manufactured by electro-brush plating. A ball-on-disc configuration with no lubricants was employed and 4 mm diameter Si3N4 ball was used as static counterpart. The results showed that with the coating time increased from 0 to 24 minutes, the overall average friction coefficient and the mass worn loss of specimens were both declined in the wear test at 450 oC for 180 minutes. The wear became slighter as the coating time increased. When the coating time were 0, 6, 12 and 18 minutes, the main wear form of samples were deep microscopic plough cutting and spalling failure. As the coating time increased to 24 minutes, its main wear form were shallower microscopic plough cutting, almost no spalling failure.
Effect of Rare Earth Addition in Plasma Nitriding on Microstructure of Chromium Electro-Plating
Authors: Huang Jie Wen , Xiong Dang Sheng , Fan Xin Min
Published: March 2010

As an active metal, chromium is easy to form oxides film on the surface, which acts as an obstacle to the nitrogen diffusion in plasma nitriding. Rare earth (RE) was introduced into the conventional plasma nitriding (CPN) to improve the nitriding behavior. Chromium coatings were treated by CPN and rare earth plasma nitriding (REPN) at 620°C for 5 and 10 hours respectively. Comparative study showed that the addition of RE prompted greatly the formation of higher nitrogen containing phase CrN, rather than Cr2N. It created a crack-free, much denser and thicker nitrides layer, which contributed to the increase of hardness. The dynamic ultra micro hardness of the samples treated by REPN was nearly 1600GPa, which was much higher than the original and the CPN treated samples. The conclusion could be drawn that compared to CPN, REPN are more efficient for chromium coating nitriding.
Influence of Isothermal Forging Temperature on Microstructure and Tensile Properties of Ti-5.8Al-4.0Sn-4.0Zr-0.7Nb-0.4Si-1.5Ta Near-α Titanium Alloy
Authors: Wang Tao , Guo Hong Zhen , Zhang Jian Hua , Yao Ze Kun
Published: March 2010

The microstructures and room temperature and 600°C tensile properties of Ti-5.8Al-4.0Sn-4.0Zr-0.7Nb -0.4Si-1.5Ta alloy after isothermal forging have been studied. The forging temperature range was from 850°C to 1075°C, and the constant strain rate of 8×10-3/S-1 was adopted. With the increase of forging temperature, the volume fraction of primary α phase decreased and the lamellar α phase became thicker when the temperatures were in range of 850°C -1040°C; The grain size became uneven and the α phase had different forms when the forging temperature was 1040°C and 1075°C respectively; The tensile strength was not sensitive to the temperature and the most difference was within 20MPa. Tensile strength and yield strength attained to the maximum when temperature was 1020°C; the ductility decreased with the increase of forging temperature, and this trend became more obvious if forging temperature was above the β-transus temperature.
Influences of Different Calcinations Ambience on Phase Composition and Morphologies of Ceramic Coatings on Ti Alloy by Micro-Arc Oxidation
Authors: Hao Guo Dong , Zhang Nai Wu , Yun Tao , Wang Jin , Lian Bo , Zheng Wei , Dong Wei Guang , Liu Yu Jing
Published: March 2010

Compound ceramic coatings with the main crystalline of Al2TiO5 (as-coated samples) were prepared in situ on the surface Ti-6Al-4V alloy by means of pulsed bi-polar micro-arc oxidation (MAO) in a NaAlO2 solution. The coated samples were calcined in argon and air at 1000 oC, respectively. The phase composition, surface morphology of the ceramic coatings were investigated by XRD, SEM and XRF. The samples were treated in argon and the as-coated ones were calcined in air at 1000 oC to study the anti-oxidation properties of the samples. The results show that Al2TiO5 was decomposed very soon and transformed into α-Al2O3 and rutile TiO2 in air. However, Al2TiO5 was decomposed very slowly in argon and the final coating surface was completely α-Al2O3. Also, the morphology of the ceramic coatings after the calcination was different. The coatings calcined in argon were fined; grains and pores were smaller than those in air. High temperature oxidation occurred very strongly in the TC4 substrate, the weight gains of the as-coated ceramic coatings and the treated ones in argon were nearly changing in the form of parabola, and the weight gains of the coated samples treated in argon were comparatively lower than those of the as-coated samples.
Numerical Modeling of the Fracture Process of a Three-Unit All-Ceramic Fixed Partial Denture
Authors: Fan Cheng , Han Li Chi
Published: March 2010

Fracture of dental all-ceramic restoration is often observed in clinic. And the fracture mechanisms and processes of three-unit all-ceramic fixed partial dentures (FPDs) are still not clear. In this paper, the fracture mechanism and process of a three unit zirconia ceramic FPDs framework under simulated mechanical loading are calculated by using a self-developed numerical modeling code, the RFPA2D code. Acoustic emission showed that the fracture mechanism was tensile failure and the crack started at the lower boundary of the framework. The result revealed that the framework fracture pattern obtained by using the numerical simulation agreed with that observed in a previous laboratory test. The fracture process could be followed both in step-by-step and step-in-step. The RFPA2D code is suitable for the use as a complement to other tests and clinical observations in studying stress distribution, fracture mechanism and fracture process in ceramic FPDs framework.
Synthesis of (TiC)pNi/TiAl/Ti Graded Material via Field-Activated and Pressure-Assisted Combustion Process
Authors: Meng Qing Sen , Zhang N. , Chen S.P.
Published: March 2010

In this paper, the synthesis of four-layered functionally graded materials (FGMs) samples of (TiC)pNi/TiAl with titanium substrate by field-activated and pressure-assisted synthesis process (FAPAS) was investigated. It was shown that the TiC particles formed by in-situ combustion synthesis process were fine and distributed uniformly. Moreover, the imposition of the electric field and the combustion reaction of TiAl is the key for the successful synthesis of the FGMs during the process. The microstructure, phase composition of the interfaces and mechanical properties of the graded material were characterized. Moreover, the sample has an excellent thermal shock resistance ability and gradient distribution of micro-hardness across the substrate layers and the surface layer.
Preparation and Damping Capacities of the NiTiSMA/FC Composites
Authors: Liu Qing Suo , Lu Cui Min , Ma Xu , Lu X.M. , Gao X.Y.
Published: March 2010

NiTiSMA/FC composites have been prepared by depositing ferroelectric ceramics films on NiTi shape memory alloy substrate with the sol-gel method. Heterojunction structure of the composites has been characterized by using X-ray diffraction and scanning electron microscope. The differences of the damping capacities between NiTiSMA/FC composites and NiTiSMA substrates have been tested by the Dynamic Mechanical Analyzer. The results show pure perovskite structure could be obtained in the FC films part of NiTiSMA/FC composites sintered at 650oC. The transitional TiO2 layer produced in-situ by the oxidation of the surface of the NiTiSMA substrate improves the combined function between the ceramic film and NiTiSMA substrate. When the temperature is lower than 20oC, the tanδ of NiTiSMA/FC composites is stabilized at 3.5%, the vibration frequencies (within 0.33-10Hz) have a small effect on damping capacities. Within the temperature of 20-40oC, there is a tanδ peak up to 5.0%.The damping capacities of NiTiSMA/FC composites are better than the pure NiTiSMA materials.
The Preparation and Photocatalytic Activity of SWNTs Doped ZnO/TiO2 Compound Films
Authors: Wang Qing , Li Xin Li , Nie Wei , Xia Yong Mei , Dai Jian Feng
Published: March 2010

The ZnO/TiO2 composite films were deposited over glass using spin coating technique by sol-gel process. Single-walled carbon nanotubes (SWNTs) were used to modify the ZnO/TiO2 films successfully in this paper. The structure and composition of the ZnO/TiO2 composite and SWNTs doped ZnO/TiO2 composite were characterized by X-ray diffraction (XRD). The morphology of samples was characterized by scanning electron microscopy (SEM). The photocatalytic activity was investigated by photocatalytic degradation of aqueous methyl orange under ultraviolet (UV) radiation. The UV-vis absorption spectra of the ZnO/TiO2 films and SWNTs doped ZnO/TiO2 films in the wavelength region 200~800 nm were obtained. The results indicate that the SWNTs addition can decrease the grain size of ZnO/TiO2, which can enhance the photocatalytic activity. UV-vis absorption spectra of SWNTs-ZnO/TiO2 showed obvious blue shifts compared with ZnO/TiO2. The optimal amount of doping SWNTs is 1% according to this research. The enhanced mechanism of the SWNTs for the photocatalytic activity in ZnO/TiO2 films was analyzed in this article.
Determination of Winding Tension in Manufacturing Strip Wound Die
Authors: Wang Qiang , Lai Xiao Li , Chen Xiu Sheng , Cai Dong Mei
Published: March 2010

The strip wound die, which is characterized by significant improvement in strength and stiffness over the conventional compound die with several layers of stress rings, is prestressed by the thin high-strength steel strips. The performance of the strip wound die is determined mainly by the winding tension during manufacture process. In this paper, the stress analysis of die body is conducted based on Lamé’s equation. Two kinds of die materials are analyzed based on strength theory in order to establish the required contact pressure in working condition which keeps the die material within the safety range. The number of winding layers can be determined by considering the strength of strip in working condition. The analytical method and the equations to determine the winding tension have been presented by following yield criterion, Euler’s equation and iso-strength principle.
Preliminary Study on VGCF Reinforced Cement Composites
Authors: Yu Jun , Xu Bing She
Published: March 2010

Preliminary study on the preparation and performance of vapor grown carbon fibers (VGCF) reinforced cement composites was carried out. VGCF were prepared from de-oiled asphalt (DOA) by chemical vapor deposition (CVD). Results demonstrated that compressive strength and electrical conductivity of VGCF reinforced cement could be significantly enhanced with very low fiber content. The resistivity decreased and compressive strength increased of cement-matrix composites with weight fraction of VGCF increasing from 0 to 0.6% fiber in the paste. The fiber content of 0.4% by mass of cement was recommended, which yielded the resistivity of 1.49×103Ωcm. That was two orders of magnitude lower than that for the same paste without VGCF (3.25×105Ωcm). Furthermore, the compressive strength increased by 28.8% as the VGCF content increases from 0 to 0.4% by mass of cement.
Preparation of NiTi/NiTiNb Laminated Alloys by Vacuum Brazing
Authors: Zhao Xing Ke , Lan Lan , Sun Hong Bo , Huang Ji Hua , Zhang Hua
Published: March 2010

NiTi/NiTiNb laminated alloys have been produced by vacuum brazing process using AgCu28 eutectic as a filler metal, and the stress-strain behavior have been researched with bending tests. The results show that the interface has a good mechanical property and no broken when the laminated alloys plate is bending tested. Differ from single shape memory alloy NiTi or NiTiNb specimen, the laminated composite show a very wide recovery temperature region, covering from -60 °C to 45 °C, within which the NiTi/NiTiNb laminated alloys show higher damping properties. This study will be useful in developing vibrating control materials.
Study on Deformation Mechanism of Tube Hydropiercing
Authors: Wang Qiang , Teng Na , Cai Dong Mei , Zhang Shi Hong
Published: March 2010

The numerical simulation of tube hydropiercing process on a typical tubular component was conducted by employing the FEM code MARC in order to investigate the deformation mechanism of tube hydropiercing. The 3D FEM models have been established in both inward and outward punching operations. Based on the calculation results of the distributions and their changes of stress and deformation, a plastic bending deformation zone in the vicinity of the hole’s edge has been discovered, which differs greatly from that in the conventional sheet metal punching process. Influence of inner pressure on the quality of hydropierced hole was also investigated.
Preparation of TiO2-g-Polystyrene Nanosphere and its Application in Toughening PS Matrix
Authors: Sang Xiao Ming , Wu Peng , Hou Gui Xiang , Yu Shou Wu
Published: March 2010

TiO2-g-Polystyrene(PS) nano-microspheres were prepared by grafted styrene monomer on the surface of nano-TiO2 particles via emulsion polymerization, and its surface and morphology were studied by Transmission electron microscopes(TEM), Fourier transform infrared spectroscopy(FTIR) and thermal gravimetric analysis(TGA). The results showed that the TiO2-g-PS nano-microsphere had a structure of sphericity composed of TiO2 and PS as core and shell respectively. The core-shell nanoparticles were subsequently used as filler in a PS matrix, and the impact strength of the TiO2-g-PS/PS composites were studied. The results showed that the impact strength of the composite material could be improved obviously, the maximum value of impacted strength of the TiO2-g-PS/PS was 1.75kJ/m2, which was 180% higher than that of pure PS. Drawing from the results, it could be confirmed that these core-shell TiO2-g-PS nanosphere fillers could toughen the PS matrix.
Interfacial Treatment of Multi-Layer Woven Silk Reinforced Epoxy Composites
Authors: R. Zulkifli , Azhari Che Husna
Published: March 2010

The aim of the project is to study the interlaminar fracture toughness, GIC of woven silk reinforced epoxy composite. Silk fibre has been treated with silane coupling agent and the silk/epoxy composites has been fabricated with different number of silk fibre layers. The processing technique used to prepare the sample is a vacuum bag cured in an autoclave. In this study, test specimens were fabricated by using silk fibre of between 8 to 14 layers. The first set of composites panel consisted of plain silk fibre while the second sets consisted of silk fibre which has been treated with 3-aminopropyl triethoxysilane. Mode I test based on double cantilever beam specimens (DCB) method have been used over all the specimens. The results of the GIC were plotted and compared. GIC of the composites in set 2 were found to be higher than the value in set 1. During the test, crack propagation is stable and no fibre bridging occurred between both sides of fracture surfaces. All the failure that occurred were at the fibre-matrix interface as seen using SEM. The GIC of woven silk/epoxy composites can be enhanced by surface treatment using coupling agent. Surface treatment and number of woven silk fibre layers has affected the interlaminar fracture properties of the composite panel.
An Investigation of Fineblanked Surface of Cold-Rolled 45 Steel
Authors: Ding Ri Xian , Guo Chen , Guo Sheng Wu
Published: March 2010

Fine-blanking process has been paid more and more attention for its shearing surface having low tearing-ratio, low roughness, low cost and high dimensional precision characteristics. It is not suitable for fine-blanking process if the carbon content of non-alloy steel is higher than 0.15% in the traditional view. Only the spheroidization is over 95%, the ideal shearing surface could obtain [1]. Methods of SEM and optical microscopy are used to research the tearing and metallographic characteristics in the region of the tearing of the shearing surface. With the help of the numerical simulation and micro-hardness testing, the tearing on the shearing surface and the shearing surface of fine-blanking is investigated. The conclusion is that without the spheroidizing annealing, 3mm thick cold-rolled 45 steel sheet having a clear flowing fiber of metallographic characteristic can get ideal shearing surface having such fine characteristics as small tear ratio, higher surface hardness and high surface finish by fine-blanking, with the help of optimized parameters from ANOVA and regression method, which considering the interaction between the height of the vee-ring indenter and the distance between vee-ring indenter and blanking contour. The present findings is great significant for expanding the scope of application of fine-blanking technology.