bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication and Photoelectrochemical Properties of CuO/TiO2 Heterojunction Nanotubes Array Film
Authors: Chen Shi Lei , Ling Yun Han , Fang Hua Jing
Published: September 2011

In order to improve the visible light response in titania photocatalysts, CuO/TiO2heterojunction nanostructures (CuO-TNT) were proposed and fabricated via the electrochemical process. TiO2nanotubes array (TNT) was first fabricated by secondary anodization, after that the CuO was doped by the electrodeposition. The thin film was characterized by X-ray diffraction (XRD), diffuse reflection spectra (DRS) and field emission scanning electron microscopy (FESEM). Besides, its photoelectrochemical properties were measured in 0.1 M Na2SO3solution. By comparing the results under different conditions of deposition, it was found that the deposition current density was a crucial parameter for controlling the morphology and the photoelectrochemical properties of the samples.
Evaluation of Thermal Performance for Vacuum Glazing by Using Three-Dimensional Finite Element Model
Authors: Han Zhi Ming , Bao Yi Wang , Wu Wei Dong , Liu Zheng Quan , Liu Xiao Gen , Tian Yuan
Published: September 2011

Simulation analysis of thermal performance for vacuum glazing was conducted in this paper. The heat conduction through the support pillars and edge seal and the radiation between two glass sheets were considered. The heat conductance of residual gas in vacuum gap was ignored for a low pressure of less than 0.1Pa. Two pieces of vacuum glazing with sizes of 0.3 × 0.3 m and 1.0 × 1.0 m were simulated. In order to check the accuracy of simulations with specified mesh number, the thermal performance of a small central area (4mm×4mm) with a single pillar in the center was simulated using a graded mesh of 41×41×5 nodes. The heat transfer coefficients of this unit obtained from simulation and analytic prediction were 2.194Wm-2K-1and 2.257Wm-2K-1respectively, with a deviation of 2.79%. The three dimensional (3D) isotherms and two dimensional (2D) isotherms on the cold and hot surfaces of the specimens were also presented. For a validity of simulated results, a guarded hot box calorimeter was used to determine the experimental thermal performance of 1.0m×1.0m vacuum glazing. The overall heat transfer coefficients obtained from experiment and simulation were 2.55Wm-2K-1 and 2.47Wm-2K-1respectively, with a deviation of 3.14%.
Evaluation of Thermal Shock Resistance of Alumina Ceramics
Authors: Li Kai , Guo Lu Cun
Published: September 2011

The thermal shock behavior of alumina ceramics tested by two different approaches, water and air quenching, using an automatic experimental set was investigated. The changes of the flexural strength before and after the thermal shock was measured and used as an indicator of thermal shock resistance. The study reveals that air quenching test has limited impact on the changes of flexural strength, whereas the water quenching yields considerable decreases of the strength. The alumina ceramics was quenched in water at various temperature differences for five cycles. It is shown that the retained strength of the quenched specimens decreases abruptly at the temperature difference of 300°C, which indicates a great severity of thermal shock in this point. The thermal shock behavior of the specimens is evaluated by quenching in water as three different temperature differences, ΔT, setting at 300°C, 600°C and 800°C, respectively. The results show, for three different ΔT quenches, the strength reductions caused by the quenching exhibit similar trends: After a sharp drop, the residual strength remains almost unchanged at a certain level for each given quenching temperature difference, and the turning points all fall in the very first five to ten thermal cycles range. And the rank of the damage severity of alumina ceramics among the three different temperature differences is: ΔT800°C > ΔT600°C > ΔT300°C
Measuring the Infinite Optical Thickness of Dentine Porcelain of the IPS E.max
Authors: Shao Long Quan , Wang Lin Lin , Liu Qi , Deng Bin , Wen Ning
Published: September 2011

Dentine porcelain disc specimens 13.0 mm in diameter with thicknesses of 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, and 6.0 mm, were made using IPS E.max color systems B, C, and D and their chromatic aberration values (ΔE) under the standard black background and the standard white background were measured using a Minolta CM-5 spectrophotometer. Then, the cubic regression formula of best fit was used to calculate the thicknesses of dentine porcelains of various color numbers at a ΔE of 1.0 and 1.5. The determination coefficient of the regression formula of color system B was 0.990–0.995, that of color system C was 0.989–0.997, and that of D was 0.993–0.998; and R2is close to 1. The results show that the regression formulas of the 11 thickness groups have good fit. The infinite optical thickness values of the IPS E.max dentine porcelains were as follows: for B1–B4, 3.263–2.711 (ΔE = 1.0) and 2.910–2.493 (ΔE = 1.5); for color system C, 2.727–2.611 (ΔE = 1.0) and 2.473–3.365 (ΔE = 1.5); and for color system D: 2.928–3.694 (ΔE = 1.0) and 2.656–2.458 (ΔE = 1.5). When the chromatic aberration tolerance is 1.5, the thickness of dentine porcelain required to reach the infinite optical thickness is less than the numerical value at ΔE = 1.0. As the thickness increases, the influence of the background diminishes and the specimen looks truer to its inherent color. The results prove that thickness of dentine porcelain positively correlates with its masking ability and that its thickness must exceed its infinite optical thickness so that its color will not be influenced by the background color.
The Correlation between Play-of-Color Effect and SiO2 Cavities Size of Australian Blue Opal
Authors: Guo Ying , Dai Zhi Xuan , Sun Hong Juan
Published: September 2011

Its play-of-color effect of Australian opal makes it unique and much more precious than any other gemstones in the world. More than 50 Australian opals were chosen to conduct the experiments, including boulder and black opals with blue-green to blue-purple color. Spectropotometer Color i5 was used to analyze the color of opal samples with CIE L*a*b* uniform color space. Dominant wavelength was put into comparison with hue angle. SEM and AFM were the main means to analyze the internal structure of opal samples, and the diameter and size of cavities of SiO2 were measured and discussed. It is revealed that the hue angle of blue-purple opal is 302.15° with 449nm as its dominant wavelength, and so the size of SiO2 cavities in the sample is about 155.32nm; the hue angle of blue opals is between (256°, 286°) with the dominant wavelength between (471nm, 485nm), and so their size of SiO2 cavities is between (154.35nm, 182.54nm); the hue angle of blue-green opal is between (183°, 213°) with the dominant wavelength between (489nm, 500nm) and so their size of SiO2 cavities is between (172.95nm, 193.66nm). Besides, the diameter and size of SiO2 cavities were analyzed against the dominant wavelength, hue angle, lightness, and saturation to reveal their correlation. It is indicated that the diameter and size of SiO2 cavities are in positive correlation with the dominant wavelength, but negative correlation with the hue angle. As the diameter and size of SiO2 cavities grow, the dominant wavelength increases but the hue angle decreases. Also they are in positive correlation with lightness but their correlation with saturation was not discovered.
Difference Analysis of Different Standard Illuminants on Yellow-Green to Green Jadeite-Jade
Authors: Wang Huan , Guo Ying , Zhang Ye
Published: September 2011

Under A, CWF, D55, D65, D75 five different illuminants, color differences of 53 natural oval Jadeite-jade with fine texture are analyzed, which color is yellow-green to dark green. All 5 tested lighting sources were compared based on the uniform color space CIE 1976L*a*b*. Jadeite-jade’s lightness L* is increasing when color temperatures of five different standard illuminants increase, and it can reach the very top of 45.72 under D75, so it appears brighter and lighter than any other illuminants and it influences the appraisal of the samples’ color. The spectrum power distribution of D75, D65 and D55 reveal the strong radiant energy in the range from 500 to 570nm, so consequently the color coordinates a*, b* and chroma C* is higher than the other two illuminants. But samples’ lightness and chroma under D55 are weaker compared to D65 and the color under D55 is dark. Meanwhile, D65 stands for the average daylight and color under D65 close to the true color of samples. Because of weakest radiant energy in the range from 500 to 540nm (green area) and strongest radiant energy in the range from 540 to 570nm (orange area) in CWF’s spectrum power distribution, the absolute value of a*=14.01 is lowest and b*=12.93 is highest under CWF, so samples’ color under CWF is green with a yellow tint. The maximum hue angle h0 is 150.42 under A, and the absolute value of a* is higher than that under CWF, so it shows stronger green tone than CWF. It is concluded that D65 is preferred to be ideal illuminants for the evaluation of jadeite-jade color green especially compared with other 4 illuminants.
Measurement and Research of the Transverse Mechanical Properties of High Performance Fibers
Authors: Huang Ji Zhi , Li Qun Hua , Yang Qi , Li Hui Jun , Ye Wei
Published: September 2011

Transverse compression stress-strain curves of a single fiber having a diameter about 10 μm must be measured to obtain transverse compression mechanical properties of high performance fibers. RJY-1 thermo-mechanical analysis instrument that the smallest division value is 0.1 μm can measure the curves of the fibers by installing some auxiliary device on the instrument. The conclu- sion obtained from the features of the curve is that the Kevlar fiber showed a yielding in transverse compression, while Carbon, Ceramic and Glass fibers did not appear the yielding, and their com- pression curves were almost straight up to the point of brittleness. Transverse compression modulus, yield and breaking stress of Kevlar, Carbon and Glass fiber can be obtained from the curves.
Study on Gemological and Mineralogy Features of Huanglong Jade
Authors: Zhao Jun , Zu En Dong , Ye Dong , Shen Nan Yu
Published: September 2011

The Huanglong jade of Zhen’an, Xiaoheishan, Supa river these three fields in Longling Yunnan were detected by general gem identify instruments. The Moh's hardness is 6.5-7, relative density is 2.60(+0.10, -0.05)g/cm3 and the refractive index is 1.53±. The electron probe backscatter atlas of samples shows that Huanglong jade is a kind of cryptocrystalline mineral aggregation. Using electron probe and X-ray spectrometer tested different field samples, got that the main chemical composition of Huanglong jade is SiO2, furthermore, including same trace elements as K, Cr, Fe, As and so on. Finally judged that Huanglong jade is a kind of cryptocrystalline (or micro show crystal) mineral aggregation which mainly formed of SiO2, named yellow chalcedony (Huanglong jade).
Reliability Evaluation of Glass Curtain Wall via Vibration Detection
Authors: Liu Xiao Gen , Bao Yi Wang
Published: September 2011

Developing efficient onsite damage detection and safety evaluation methods for glass curtain wall is still a challenging task. In this work, a simple approach to predict the failure and risk of falling down of curtain wall glass was developed through the relationship between the natural frequency changes and the declined reliability of the structures. Natural frequencies of the curtain wall glass under various clamping conditions were determined using dynamic tests. It was discovered that, with the decrease of the clamping force at the boundary of the glass specimen, the measured natural frequencies decreased linearly. Thus, the in-service capacity in edge clamping (e.g. boundary is loosed or failure of the supporting structure) of the curtain wall glass can be identified by its natural frequency changes. The expected lowest safety natural frequency of a curtain wall glass (given elastic parameters, shape and size) is given. The implementation of this detection method is described, and the practicability and feasibility validated.
Studying Blended Cement Paste with Nuclear Magnetic Resonance Relaxation Time
Authors: Jin Dan , Yao Wu , Wang Hong Zhi
Published: September 2011

The pore structure of cement paste has a relationship with its strength and durability. An appropriate method of measurement is a prerequisite to study the pore structure of cement paste. Among many test methods, Nuclear Magnetic Resonance (NMR) relaxation time is a novel testing methods to study pore structure of cement paste. Different from previous research object is limited to white cement, the test sample in this paper is the blended cement paste containing mineral admixture and has been widely used in practical engineering applications. The factors of pore structure are water to cementitious material ratio, kind of mineral admixture, and mineral admixture content. Measure the same sample at four different ages to obtain the relaxation time distribution to reflect the pore structure. The test results show that, in most cases, the distribution curves of the same kind of paste are in good agreement, and the change of relaxation time distribution of the blended cement paste with different ages can be interpreted as the characteristic of the mineral admixtures in cement paste. So the NMR relaxation time is suitable for study on the blended cement paste. However due to side effects caused by iron content and unsaturated water in gel pore, this method needs further improvement.
Determination of Main Component and Purity of Oxide by Mass Balance of Difference-Determination for ZrO2+HfO2
Authors: Zeng Jing , Xu Jian Ping
Published: September 2011

Gravimetric and coulometry are recognized as primary method in actual measurement, so their accuracy can be appraised by their precision. The precision of measurements of ZrO2+HfO2 by mass balance of difference and gravimetric by precipitation mandelic acid was compared. It shows that the precision of mass balance of difference (0.022%) is better. There is no significant difference between the two averages. So the accuracy of mass balance of difference is higher as its precision is better.
Assessment of Ultrasonic-Ethanol Extraction to Determine the pH Value of Hardened Cement Pastes
Authors: Xing Xiao Ming , Yao Wu
Published: September 2011

A simple method is presented to extract the pore solution of hardened cement pastes during the first 28 days and to measure the pH value, which is dependent on anhydrous-ethanol extraction (AEE) and improved by the assistance of ultrasonic vibration generator. The results were compared with the pore water expression (PWE) and anhydrous ethanol extraction through observing the variation tendency of pH values along with time and different water-cement ratios (w/c). The study showed that as w/c decreased, the pH value had a rising tendency; the density of [OH-] extracted by ultrasonic-ethanol extraction (UEE) method is 4-5 times higher than that by AEE method, which indicates the feasibility of UEE method.
Accelerated Carbonation Test Equipment of Concrete
Authors: Yang Wen , Wang Jun , Ji Xi Xian
Published: September 2011

Based on concrete carbonation test methods available and common carbonation test equipments, this article designed and developed a new concrete carbonation test equipment. The device consists of a gas storage tank and many independent small carbonation chambers. With a compact structure, the device is small, simple and practical. With its advantages of not only improving the CO2gas utilization, but also making full use of available space with the design of several smaller carbonation chambers, the device could carry out more carbonation tests without affecting their progresses. The device has a wide usage and promising future.
Phase Composition, Microstructure and Mechanical Properties of Aluminous Cements Containing Magnesium Aluminate Spinel
Authors: Li Jin Hong , Tong Ling Xin , Zhou Wen Cai
Published: September 2011

A new type aluminous cement containing magnesium aluminate (MA) spinel was prepared from mixtures of limestone, magnesian and bauxite at different ratios by sintering process. The phase composition, microstructure and mechanical properties of aluminous cements containing magnesium aluminate spinel were investigated in this paper. According to the XRD results, the magnesium aluminate spinel (MA),calcium monoaluminate (CA) and calcium bialuminate (CA2) are the primary phases of the obtained aluminous cements with a small quantity of calcium silicoaluminate (C2AS) and remained alumina (Al2O3). The results of SEM indicate that the MA mainly exist in the shape of octahedron with the length of about 2-5 μm, and it is agglomerated with the tabular or flaky-shaped CA among the obtained aluminous cements. In addition, the compressive strength of castables containing obtained aluminous cements increase obviously with the content of CA rising or the curing time increasing.
Phase Behavior of Silica Brick Used in Carbothermal Reduction
Authors: Pan Zi He , Huang Zhao Hui , Li Wen Juan , Liu Yan Gai , Fang Ming Hao
Published: September 2011

In this study we observed the phase behavior of silica brick used in the process of carbothermal reduction. At 1550°C, there are liner β-SiC in clumps huddled together; At 1550°C, short line clumps changed into filamentous, mixed together. There are many particles and some β-SiC lines and few filamentous β-SiC at 1600°C . Different ratio of carbon coke also effect the phase behavior. From the results we obtained SiC powders. SiC refractory powders were prepared via carbothermal reduction method using used silica bricks as raw materials. The effects of carbon content, temperature and holding time on the phase composition and microstructure were analyzed. XRD and SEM analyses show that: β-SiC refractory powders were synthesized at 1600°C for 6 h with100 wt% excessive of carbon content. With the increase of carbon content, the reaction temperature and holding time, content of β-SiC gradually increased while that of cristobalite decreased.
Effect of Atomic Oxygen Exposure on Polyhedral Oligomeric Silsesquioxane/Polyimide Hybrid Materials in Low Earth Orbit Environment
Authors: Duo Shu Wang , Song Mi Mi , Liu Ting Zhi , Hu Chang Yuan , Li Mei Shuan
Published: September 2011

A novel polyimide (PI) hybrid nanocomposite containing polyhedral oligomeric silsesquioxane (POSS) had been prepared by copolymerization of octa(aminophenyl)silsesquioxane (OAP-POSS), 4,4’ -oxydianiline (ODA), and pyromellitic dianhydride (PMDA). The AO resistance of these POSS/PI hybrid films was tested in the ground-based AO simulation facility. Exposed and unexposed surfaces have been characterized by X-ray photoelectron spectroscopy and FTIR. The XPS data indicate that the carbon content of the near-surface region is decreased from 63.6 to 19.3 at% after AO exposure. The oxygen and silicon concentrations in the near-surface region increase after AO exposure. The data reveal the formation of a passive inorganic SiO2 layer on the POSS/PI hybrid films during the AO exposure, which serves as a protective barrier preventing further degradation of the underlying polymer with increased exposure to the AO flux. SEM images showed that the surface of the 10 wt% POSS/PI became much less rough than that of the pristine polyimide. The AO resistance of the POSS/PI hybrid films is up to several tenfold than that of the pristine polyimide.
Investigation of Abrasive Wear in the Dry Belt Grinding of Titanium Alloy
Authors: Huo Wen Guo , Xu Jiu Hua , Fu Yu Can , Qi Hou Jun
Published: September 2011

This paper was dedicated to elucidate an investigation of abrasive wear and surface topography of Titanium alloy TA15 on dry grinding with zirconia alumina belt. In the investigation, experiments were performed on milling machine XS5040 equipped with assembled belt grinding device. The wear abrasive, surface morphology of machined belt in different phase were analyzed using 3D viewer microscope. The results show that the wear of belt abrasive is mainly steady attritions wear since zirconia alumina belt was stable on dry grinding. At higher grinding force, the abrasive was found to undergo dislodging prior to being gradually worn. So zirconia alumina belt has excellent performance in the dry grinding titanium alloy.
Process Parameter and Cutting-Tool Geometry Study for Precision Face Turning of a Clock Dial
Authors: Lin Shen Yung , Lin Y.H. , Hsu M.S.
Published: September 2011

After the processing of a clock dial, the precision dimension and uniform distribution of the tool-trace pattern on the dial surface have a connection with luster image and attractiveness, which in turn would have an impact on the additional values and prices for a clock. Through a systematic investigation among the lathe structure, process parameter and cutting-tool geometry in advance, the total results indicated that the rigidity of the lathe structure and the precision of the slider movements are excellent and they had only a little effect on the surface-related quality for a dial face turning. Hence, the combination of process parameter and cutting-tool angle becomes more essential. End face turning simulation and experiment of a copper alloy were thus conducted in this paper, and the chip formation process and machined surface-related quality are investigated, respectively. The effects of cutting tool geometry and process parameter on the results of chip formation, surface rough, tool-trace pattern and luster uniformity are investigated, and these results are also compared with each other. The results show that when larger clearance and rake angles used in conjunction with a lower feed rate, no matter how much cutting speed was enhanced, the surface-related quality of a dial surface is not good. However, when these two larger angles used combined with a larger feed rate, the quality of a dial surface would slightly be improved. By using smaller clearance and rake angles along with the higher feed rate and cutting speed would obtain a better surface-related quality with uniform luster and attractiveness.
Experiment Study on Deflection of Aluminum Alloy Thin-Wall Workpiece in Milling Process
Authors: Han Bing , Ren Cheng Zu , Yang X.Y. , Chen Guang
Published: September 2011

The deflection of Aluminum alloy thin-wall workpiece caused by the milling force leads to additional machining errors and reduces machining accuracy. In this paper, a set of experiments of milling thin-wall workpiece were carried out to study the deflection of thin-wall workpiece. The workpieces, with different types of material and different thicknesses, were machined on CNC machining center. The deflections of workpiece were measured by a three-coordinate measuring machine. Effects of Aluminum alloy material and thickness on deflection are discussed based on the experimental data.
Prediction of the Hardened Layer in Traverse Cylindrical Grinding-Hardening
Authors: Nguyen Thai , Zhang Liang Chi
Published: September 2011

A finite element heat transfer model incorporating a moving heat source has been developed to predict the temperature field in traverse cylindrical grinding. The model was then applied to analyse the grinding-hardening of quenchable steel 1045. It was found that in the region where the grinding wheel had an entire contact with the workpiece, material would experience a heating-cooling cycle, enabling the generation of a uniform hardened layer. In the transient regions at the two ends of the workpiece where the wheel-workpiece contacts were partial, the material was not hardened but experienced an annealing process. The results were in good agreement with the experimental observations.
Investigation of Surface Quality on Dry Belt Grinding of Ti6Al4V Alloy
Authors: Huo Wen Guo , Xu Jiu Hua , Fu Yu Can , Qi Hou Jun
Published: September 2011

This paper deals with an investigation of surface integrity of Ti6Al4V alloy with zirconia alumina and SiC belts. The experiments were conducted under dry grinding environments in milling machine XS5040 equipped with belt grinding device. Microcosmic geometry parameters were measured with TALYSURF5 instrument, the surface morphology machined workpiece and the phase structure was analyzed using 3D viewer microscope, surface hardness for ground surface was measured by HXS-1000A instrument. The results show that surface quality maintain better level during a long period, the grinding affected zone was small(≤15μm), zirconia alumina belt has excellent performance than SiC belt during dry grinding Ti6Al4V alloy.
The Effect of Rare Earth on the Clearance of Carbon during High Speed Polishing of Diamond Films
Authors: Zhou Li , Huang Shu Tao , Xu L.F.
Published: September 2011

A new setup for polishing of diamond films on a high speed rotating stainless plate has been developed, and a rare earth metal plate was used to clear the carbon atoms diffused into the polishing plate. The surface morphology and clearance mechanism were studied by using scanning electron microscopy and X-ray photo-electron spectroscopy before and after polishing, respectively. The results showed that the chemical reaction between the rare earth metal and carbon diffused into the polishing plate took place and the rare earth metal could clear the carbon element effectively during the super-high speed polishing.
Cutting Performance of High Speed Steel Hobs with Different Coating in Dry Hobbing
Authors: Kubo A. , Qiu Hua
Published: September 2011

This paper explains the results of a systematic dry hobbing experiment performed on a general mechanical transmission type of hobbing machine. The HSS hobs with different combinations of coat materials and coating states display significant variations in tool life. A TiN coating hob demonstrates the best cutting performance although the coating cost is the lowest. Furthermore, some meaningful discussions related to the dry hobbing mechanism are also presented.
Study on the Characteristics of Discharge Waveform in Micro EDM Deposition Process
Authors: Peng Zi Long , Li Yi Nan , Wang Z.L.
Published: September 2011

Based on the analysis of micro electrical discharge machining (micro EDM) principle, the process conditions of micro EDM deposition has been obtained. Micro EDM deposition is a new EDM method, in which the process conditions includes selecting air as working medium, short pulse duration, long pulse interval, low discharge current and setting the tool electrode as anode. In micro EDM deposition experiments, two types pulse generators of transistor type and RC type are applied respectively. The characteristics of discharge waveforms using each type pulse generator are researched. Results show that both two types pulse generators can be applied in the micro EDM deposition process. The transistor type is easy to obtain the same single discharge energy, but short circuit will damage the deposited material. While RC type can adjust discharge energy according to the discharge gap state, which is well used in micro EDM deposition process with the high deposition rate.
Numerical Solution of Tuned Mass Dampers for Optimum Milling Chatter Suppression
Authors: Yang Yi Qing , Chen T.T.
Published: September 2011

The most common tunings for the TMD in the field of vibration suppression areH∞andH2. However, regenerative machine tool chatter is a complex problem with many variations, which therefore requires a new tuning for the optimum chatter suppression. The real part based tuning is investigated numerically by employing the minimax numerical approach, which aims to maximize the minimum real part of the primary structure under the harmonic excitation. The performances of multiple TMDs system are discussed. A face milling case is employed to verify the benefits of multiple TMDs in increasing the chatter free depth of cut. It is concluded that multiple TMDs configuration are more effective than single TMD in chatter control.
Study on Spindle Thermal Field Distribution and Thermal Errors of Horizontal Machine Tool
Authors: Ma X.B. , Qiu Jian , Liu Qi Wei , Lin J.F.
Published: September 2011

Research on thermal field and thermal errors of NC machine tools were carried on using infrared imaging and laser distance measurement technologies. It mainly focused on the analysis of thermal field distribution of a three-axis horizontal machining center and the relationships between thermal behaviors and their temperatures. It was found experimentally that spindle thermal errors is one of the main errors sources of NC machine tools, and spindle thermal errors has been observed to be closely linked to the temperature distribution of machine tools. There was a significant increase in the axis positioning error related to the spindle temperature increasing. The elongations on Z direction are much larger than the extensions of X and Y directions. Finally, a method by adjusting spindle temperature to control spindle thermal errors was taken.
Thermal Analysis of Dedicated Computer Based on ANSYS
Authors: Zhang Y.R. , Gao L. , Li S.J. , Bi H.X.
Published: September 2011

After creating the three-dimensional models of dedicated computer, models can be smoothly put into ANSYS through interface between Pro/E and ANSYS. By selecting the grid cells, setting parameters of material properties, dividing grids, applying load and boundary conditions and post-processing, the temperature contours of the whole case and its key components are got. Compared with the test results, it was verified that the feasibility and rationality of carrying out thermal simulation by ANSYS software, providing a theoretical basis for the designers to optimize dedicated computer case.
Algorithm for the Inverse Kinematics Calculation of Cross Rods Parallel Machine Tools Based on Lie-Algebras
Authors: Fang X.F. , Tong Y.H. , Zhao R.Y. , Zhang S.W. , Wang Tong Yue , Liu Yuan Wei
Published: September 2011

In order to solve the problems that traditional kinematics model built by the method of D-H parameters can only reflect relative movements between adjacent components and can't express directly the spatial poses of every component relative to static platform, Lie-algebras is used this paper to establish the product of exponential formula of forward direct kinematics of every branch chains. The elimination method and Paden - kahan sub-problems are used to calculate joint variables. Then the quick and intuitive inverse algorithm of cross rods parallel machine tools is acquired. The algorithm provides reliable proofs for the analysis of error compensation, kinematics interference and singularity. Finally we prove our theory with an example of an actual parallel machine tool.
A Pipeline Designed Reconfigurable CNC Architecture
Authors: Dong Jing Chuan , Wang Tai Yong
Published: September 2011

This paper proposed a pipeline based reconfigurable architecture for CNC controllers. The architecture consists of an upper controller and a NC Microcode Processor (NCMP). The control software in the upper controller is a multi-thread program, including a management thread and a NC pipeline thread. The NC pipeline thread in the upper controller converts the machining program into NC Microcode (NCM), which is optimized for the real-time execution in NCMP. A pipelined feedrate plan algorithm is developed for the proposed architecture. The algorithm features a reconfigurable structure and look-ahead ability for high speed machining. Two prototype systems were built to demonstrate the feasibility of the proposed architecture. The experimental results indicate that the NC pipeline is highly reconfigurable and flexible in design compared to the classic implementation.
A Novel Method for Roll Error Measurement of a Linear Worktable of a Machine Tool
Authors: Han L. , Zhang Da Wei , Cui Liang Yu
Published: September 2011

This paper proposes a multi-step and multi-probe method to measure the roll error of a linear worktable during its movement. Two displacement sensors are used and two measurement steps are employed. Compared with two displacement sensors and a sensing target with high flatness method or a method using autocollimator, this method is in low cost and easier to be carried out. In proposed system, the slope information of roll error is obtained by sensor fusion technology. Roll error estimation algorithm is derived, and sequential-two-point method is used to sample sensors’ signal. Simulation and experimental results show the feasibility of the proposed method.
Study on Drilling Method of Small Diameter Deep-Hole of Titanium Alloy by Using DF of Gun Drill
Authors: Shu Liu Yan , Wang T.Q. , Fu Q.Q.
Published: September 2011

By the characteristics of gun drill and the mechanisms of DF (Double Feeder) system of outside the chip, and analyzing the processing characteristics of titanium alloy and the characteristics of small diameter deep hole, the drilling device DF system of gun drill is designed, and in order to better guarantee the accuracy of parts, the monitoring system between input oil installation and gun drill fixture are designed also. The device of drill the small diameter deep hole of titanium alloy, the value of surface roughness of the parts are Ra3.2-0.4μm and the phenomenon of the ring scratches eliminated.
Side Wrinkling Characteristics in Rotary-Draw Bending Process of Thin-Walled Rectangular 3A21 Tube
Authors: Zhao Gang Yao , Liu Yu Li , Tian Shan , Yang He
Published: September 2011

Side wrinkling may be produced during rotary-draw bending process of thin-walled rectangular 3A21 aluminum alloy tube if the process parameters are inappropriate. To study the side wrinkling behavior, a three-dimensional finite-element model of the process was developed based on ABAQUS/Explicit code and its reliability was validated by experiment. Then, the side wrinkling characteristics of the tube were investigated. The results show that the side wrinkling wave height in the inner edge of the tube is smaller than that in the out edge of the tube, and the side wrinkling wave height in the neutral layer of the tube is minimal. With the bending process, the side wrinkling wave goes through producing, developing and stabilizing three stages in turn. After bending angle reached 30°, the side wrinkling wave height keeps almost unchanged. Furthermore, the number of the half side wrinkling wave increases evenly.
Process Parameter Optimization on Pneumatic Bulging for Abnormity Thin-Wall Pot
Authors: Song Z.P. , Cui S.P. , Huang T.
Published: September 2011

To enhance the forming quality of pneumatic bulging for abnormity thin-wall pot and reduce such forming defects as severe wall thickness reduction and fold breaks. Based on numerical simulation, this article analyzes the impact of the friction factor, die radius of curvature, pot wall thickness and load pressure on the wall thickness reduction rate, maximum stress and axial contraction. The experiment result is consistent with the numerical simulation. The research results have greater practical value to process optimization and process control.
The Dissolution Mechanism of Copper Weld Brazing with Cu-Based Brazing Alloys
Authors: Li Yi Nan , Peng Z.L. , Yan J.C.
Published: September 2011

In this paper, the dissolution mechanism of copper weld brazing has been researched. The thickness losses of Cu foil in contact with molten Cu-P and Cu-Ag binary alloys at different temperatures have been studied. And the dissolution rate constants in both alloys is calculated and exists following relation: kCu-P(T)=10kCu-Ag(T), which explains the special phenomenon that the dissolving amount of copper in Cu-P liquid alloys is larger than that in Cu-Ag liquid alloys by using weld brazing technology. The dissolution rate of copper in filler metals is the main reason to realize weld brazing. It can be concluded that element P is indispensable in filler metals as the function of accelerating dissolution during weld brazing.
Study on the Maximum Forging Load and Final Face Width of Powder Spur Gear Forging
Authors: Yang Tung Sheng , Li J.Y. , Liu C. Y.
Published: September 2011

Powder forging combines powder metallurgy and forging technology, thus possess the advantages of both processes that result in both stronger and yet more versatile products with complicated geometry and arbitrary alloy compositions. For complete filling up, predicting the power requirement and final face width is an important feature of the powder forging process. In this paper, a finite element method is used to investigate the forging force, the final face width and the density variation of the spur gear powder forging process. In order to verify the FEM simulation results, the experimental data are compared with the results of the current simulation for the forging force and the final face width of spur gear. The influences of the parameters such as modules, number of teeth, the initial relative density, the ratio of the height to diameter of billet and friction factor on the forging force and the final face width of the billets are also examined.
Research on the Propagation of the Crack Inclined across the Interface in the Cermet Cladding Part
Authors: Yang Jun Ru , Li Z.Q. , Huang C.Z. , Wang X.F. , Wang G.C.
Published: September 2011

A new comparative propagation property parameter CP suitable to judge the propagation of the interface crack in the cladding part is proposed. The propagation criterion for the crack inclined across the interface is established. The theoretical research on the CPxA and CPxB of this interface crack propagating in the clad and substrate separately is carried out. The propagation law of the interface crack in the cermet cladding part is investigated with an example. The research results show that, within the ranges of the studied parameters, CPxA is bigger than CPxB, and that the crack initially propagates in the clad.
Thermostablity Study on Microstructure and Microhardness of Laser Shock Processed Ti-6Al-2.5Mo-1.5Cr-0.5Fe-0.3Si
Authors: Li Qi Peng , Li Ying Hong , He W. , Li Yu Qin , Nie Xiang Fan , Zhou L.
Published: September 2011

In this paper, the microstructure and microhardness of laser shock processed (LSP) Ti-6Al-2.5Mo-1.5Cr-0.5Fe-0.3Si titanium alloy with and without annealing were examined and compared. The titanium alloy samples were LSP processed with 3 layers at 4.24GW/cm2. Some of the samples were vacuum annealed at 623K for 10 hours. The microscopic structure with and without annealing were tested and analyzed by SEM, TEM. The results indicated that after LSP, the shock wave provided high strain rate deformation and led to the formation of ultra-fine grain. Comparing with the samples without annealing, the dislocation density was lower and the grain-boundary was more distinct in the annealed samples, but the sizes of the ultra-fine grain didn’t grow bigger after annealing. On the other hand, the microhardness measurement was made on the cross-section. It is obviously that the laser shock processing improved the microhardness of the Ti-6Al-2.5Mo-1.5Cr-0.5Fe-0.3Si for about 12.2% at the surface, and the hardness affected depth is about 500 microns. The microhardness after annealing is 10 HV0.5lower, but the affected depth is not changed. The titanium alloy after LSP is thermostable at 623K; thus break the USA standard AMS2546, in which titanium parts after LSP are subjected in subsequent processing should not exceed 589K.
Surface Modification on Polyurethane of Bio-Electrodes Implanted for Deep Brain
Authors: Qin G. , Liu Ya Xiong , Bai Z.X. , Wang H.Y. , Du R.K.
Published: September 2011

For bio-electrodes implanted in deep brain, electrode materials will affect the fibrous encapsulation formed on the interface of bio-electrodes and brain tissue which would reduce the operating effect of the bio-electrodes. To reduce or eliminate the fibrous encapsulation layer, N2/H2 plasma treatment process is used to modify the polyurethane which is the most materials of the bio-electrode. The amino groups are produced on the polyurethane surface. After these amino groups have a polymerization reaction with the polypeptide molecule, a layer of the polypeptide molecule is formed on the polyurethane surface of the bio-electrode. These modified bio-electrodes are implanted in the deep brain of the rats for two weeks to observe the immune response and the morphology of the cells on the interface of the bio-electrodes. The results of the experiments indicate that the polypeptide molecules on the polyurethane can improve the immune response of the cells and affect the growth of the fibrous encapsulation on the interface of the bio-electrodes.
Development of Micro-Alloying Ultra-Fine Grain High Strength Steel Produced by EAF-TSCR
Authors: Gao Ji Xiang , Mao Xin Ping , Li L.J.
Published: September 2011

Based on the characteristics of raw materials in EAF-TSCR, the composition of VN micro-alloyed was designed, the processes of the steelmaking, continuous casting, soaking, rolling, cooling were controlled, and at last the VN Micro-alloying high strength steel with ultra-fine grain was developed. The ferrite grain size of the steel reaches 3.0 to 4.0 microns, and the yield strength of which reaches 550MPa. Besides, the steel processes good toughness, cold formability and weldability. In the end, the strengthening mechanism of the ultra-fine steel was discussed.
Deforming Capability of Heat-Treated and Modified Al-40Si Alloy
Authors: Cai An Hui , Tan X.F. , An W.K. , Li X.S. , Zeng J.J. , Luo Y. , Li Tie Lin
Published: September 2011

The Al-40Si alloy was modified by 0.5 wt% Sr addition and heat treated using the solution treatment and aging treatment. Its deforming capacity and hardness variance were investigated. The microstructures of the deformed samples were analyzed using optical microscope. The results show that the hardness increases with increasing of the deformation degree. When the deformation ratio exceeds 10.1 %, the hardness sharply increases. When the deformation ratio exceeds 20.4 %, the hardness maintains almost unchanged. In addition, although the cracks are not observed on the surface when the deformation ratio is less than 14.6 %, the primary Si phase is cracked. Thus the critical deformation ratio of the studied Al-40Si alloy is 10.1 %.
Molecular Dynamics Simulation on the Tension Deformation of Carbon Nanotubes
Authors: Zhou M.Y. , Tian Yan Ling , Ren Z. , Zheng H.Y. , Wei R.B.
Published: September 2011

Molecular dynamics (MD) simulations were used to investigate the elastic properties of carbon nanotubes (CNTs). Displacements were loaded to CNTs on the tension deformation simulations. In order to better understand the relationship between Young’s modulus and the structure of the CNTs, different chiralities and diameters were involved. It is found that the Young’s modulus will be no more sensitive as in the single-walled carbon nanotubes (SWCNTs) with increasing walls. The tension deformation results also indicate that SWCNTs have better elastic property compared to multi-walled carbon nanotubes (MWCNTs).
Research on Design of Hydraulic Support Based on Virtual Prototype Technology
Authors: Zhang Y.K. , Xiao L.J. , Zhong Pei Si , Li W.
Published: September 2011

According to the design theory and method of complex product based on virtual prototype technology, with design characteristics of the hydraulic support, the system framework of the hydraulic support is established. The three-dimension (3-D) digital model of the hydraulic support virtual prototype conformed to the actual requirement is built. The static and dynamic analyses and simulation to the model are carried out. The research results show that the designed hydraulic support meets its actual work requirements.
Dynamic Characteristic Analysis and Structural Modification of a 5-Axis Horizontal Machining Center Considering Joint Surface
Authors: Shi Y.G. , Zhao Xing Yu , Zeng Li Qiang , Wang H.Y. , Zhang Da Wei
Published: September 2011

In order to make a 5-axis linkage horizontal machining center have better dynamic characteristics, considering the influence of joint surface, dynamic characteristic analysis is conducted to the machining tool. Based on finite element modal analysis results, the weak link is found and optimized. Through the finite element calculation and analysis, the structure rigidity obviously raises after optimization. This offers a new idea on how to improve the rigidity of complete machine of machining tool for later research.
Morphological Filtering Algorithm for Estimation of Tool Wear in CNC Milling Machining
Authors: Ning Qian , Wang Tai Yong
Published: September 2011

Estimation of tool condition has very important meaning to improve the product quality, continuous machining ability and reliability of the manufacturing system. Based on mathematical morphology, a systematic approach is developed to implement online estimation of tool wear in this paper. As the nonlinear filter, morphological filter is selected to reduce the higher frequency noises before feature values extraction. The feature vector consists of original characteristics of vibration signal and cutting force signal. Then, they are input into SVM for training and testing. Experiments show that this method can achieve tool wear estimation effectively.
Exploring the Steel Bar Logistics Value Chain in China
Authors: Lu D.W. , Wang M.S.
Published: September 2011

The aim of the paper is to present a conceptual exploration on how a newly emerged distribution service business in China is developed, interpreted and modelled. The study draws on a recent case from a fast expanding 3PL company in China and frames the case with a conceptual flow-model and interprets it mathematically by using a linear bi-level programming algorism. It finds that recent advances in the steel bar logistics practices in China have been phenomenal. The emerging business model is set to define the standard for the industrial sector. The logistics process and structure changes were primarily driven by not only the higher returns on investment to the participating members individually, but also by that of the total supply chain. The emerged steel bar logistics service model studied here represents a new business evolution in the 3PL service industry ever seen in China. The application of bi-level programming algorithm in assessing returns on investment and the total supply chain value has been original.
Aircraft Skin Stretch-Forming Die Light-Weight Design Using Topology Optimization
Authors: Zhu Ji Hong , Wang H. , Zhang W.H. , Gu X.J.
Published: September 2011

The purpose of this paper is to use the topology optimization method to solve the light-weight design problem of large aircraft skin stretch-forming die. The platform of ABAQUS is firstly used for numerical simulation of skin stretch-forming. And the surface load conditions are therefore obtained. The topology optimization is carried out accordingly to maximize the structural stiffness with the material properties and the boundary conditions properly defined. Referring to the obtained topology design, the optimal structure is reconstructed and then evaluated by the non-linear numerical simulation of stretch-forming. Compared with the traditional design, the numerical results have shown that the topology design can improve the stiffness and strength of the stretch-forming die significantly.
Integrated Optimal Design of Complex Multi-Component System in Three-Dimension
Authors: Xia L. , Zhu Ji Hong , Zhang W.H. , Li J.S.
Published: September 2011

The layout of movable components and the topology of the connecting structure are optimized simultaneously in the integrated optimal design of multi-component system for compliance minimization. In this paper, a Heaviside function based approach is developed for sensitivity analysis with respect to location design variables of components. The material discontinuity across the component boundary is approximated as a smooth transition by means of the Heaviside function. This enables the sensitivity analysis with respect to location design variables is carried out in an analytical way as easily as for pseudo-density variables. To demonstrate the validity and efficiency of the new approach, two 3D problems of multi-component system are dealt with for the first time with success.