bluuebunny/crossref_metadata_2025 huggingface dataset:
A General Approach to the Equalisation of Partial Contact Ratios in 3K Transmissions
Authors: Golenko Andrzej
Published: September 2011

The equalisation of the approach and recess contact ratios is one of the methods aiming at higher efficiency in any meshing toothed pair. Hori, Kurita and Hayashi implemented this method to the design of a 3K planetary gear with a common planet gear (the Mechanical Paradox) by a purposeful modification of the addenda of each of the 3 meshing toothed pairs. The author verified this method in one of the previous publications and proposes here a more general design approach aiming at better equalisation still at the stage of selecting the numbers of teeth in the transmission. The results confirm the purposefulness of this approach.
Modernization of the Trailer for Tyre/Road Rolling Resistance Measurements
Authors: Woźniak Ryszard , Taryma Stanislaw , Ronowski Grzegorz
Published: September 2011

In the article the ways of defining tyre rolling resistance are presented. The advantages of the laboratory tests of tyre/road rolling resistance and the advantages and the disadvantages of on the road tyre/road rolling resistance tests are described. The description of the special trailer used for tyre/road rolling resistance measurements designed and constructed in Faculty of Mechanical Engineering at Gdansk University of Technology is presented also. The trailer during it’s modernisation was equipped with special test systems which compensate the impact of disturbance factors such as: aerodynamic drag and inertia force acting on the tested tyre, slope of the road, tilt of the trailer and vibrations of the measuring arm. This article contains the description of only one compensation system applied in the measuring trailer which eliminates the aerodynamic drag. The conclusions which came from the measurements performed using this compensation test system are included.
Problems of Analytical Determination of Journal Bearing Bush Fatigue Strength Estimates
Authors: Gawarkiewicz Rafał , Sikora Jan , Siwek Boguslaw
Published: September 2011

Problems connected with determination of stress distribution in sliding layer of thin-walled bearing bushes, investigated in bearing fatigue test rigs, have been presented. Using an example of plain bearings tested in the fatigue machine SMOK (built at the Gdańsk University of Technology) problems with obtaining a convergence of iterative procedure for determining the fatigue strength estimators of bearing alloy surface layer are analyzed. Calculations consisting in successive iterations of pressure distribution in oil film and corresponding elastic deformation of the bearing bush and housing were based on finite-element method and utilized ANSYS program. The objective of calculation was the estimation of values of radial, tangential, axial and reduced stresses in surface layer of the bearing bush corresponding to experimentally determined load magnitudes leading to fatigue cracks initiation. The convergence of analytical procedure has been achieved by the use of a relaxation method.
The Influence of Geometrical Parameters on the Friction Process in the Needle Bearing
Authors: Nachimowicz Jerzy , Korbut Robert
Published: September 2011

The article analyses the process of friction in the needle bearing as the function of the alterations of geometrical parameters, namely the diameter of the shaft – D, the needle – d and the bearing clearance. The change in the relation between the diameters D and d results in the change of the contact area of the friction pair; in the case of two shafts with parallel axes (the needle of the bearing and the shaft pin) the contact area, if compared with the analogical process in the ball bearing, alters significantly and leads to resistance in motion. There are two types of friction in the needle bearing: the rolling friction and the sliding friction; the analysis of the movement of the bearing elements enabled the estimation of the extent to which the sliding friction matters in the overall balance of motion resistance. The article also defines the type of wear as the function of initial clearance.
Crack Propagation in Zirconia MgO-PSZ Ceramic Material
Authors: Karaszewski Waldemar
Published: September 2011

The properties of ceramic materials such as elevated hardness, high temperature capability, low coefficient of thermal expansion are of interest for rolling element materials. Widely used ceramic materials in engineering applications are silicon nitride, zirconia and alumina. The paper presents an experimental study of the fatigue life of MgO-PSZ ceramic material in lubricated contact with defined types of cracks. A ceramic angular contact bearing operation was simulated using a four-ball machine. Zirconia balls were artificially damaged with pre-cracks. Ringformed pre-cracks were propagated on the ball surface by a blunt impact load using a tungsten carbide ball under five various impacts. Research of the presented paper shows that fatigue failure under rolling contact loading is markedly sensitive on ringformed pre-cracks made by a different impact energy (drop height). Propagation of surface pre-cracks takes place under a fatigue load. Primary and secondary surface crack propagations are described.
A New Technique of Spine Disease Treatment Supported by ADRSK1 Device
Authors: Grymek Szymon , Pawelec Mateusz
Published: September 2011

Scoliosis is one of the most frequently occurring defects of human body. Its effective rehabilitation requires a suitable methodology of corrective exercises and devises which support the implementation of these exercises. The subject of scoliosis and its rehabilitation is brought up in this paper. The most popular rehabilitation devices as well as the new ADRSK1 apparatus from Gdańsk University of Technology are presented. The structure, the principle of operation and advantages compared to existing devices of the ADRSK1 are described.
Dynamics Conscious Approach to Tribometer Design and Tribo-Testing
Authors: Lubinski Jacek I. , Grymek Szymon , Druet Krzysztof , Olszewski Henryk
Published: September 2011

In the paper findings are discussed on the issue of dynamic characteristics of a tribometer as a factor influencing the result of the tribological experiment. An advanced approach to tribo-testing is attempted with integrated dynamic analysis of the tribometer and the sliding pair. The fundamental idea is explored of the tribometer being regarded as any machine in which friction is inflicted with all the resulting consequences such as e.g. wear, vibration, fatigue etc. The research described is concentrated around friction induced vibration and it’s potential consequences to the results obtained in a tribological experiment. General methodology used for the task described is presented.
Extrusion Benchmark 2011: Evaluation of Different Design Strategies on Process Conditions, Die Deflection and Seam Weld Quality in Hollow Profiles
Authors: Selvaggio Alessandro , Segatori Antonio , Güzel Ahmet , Donati Lorenzo , Tomesani Luca , Tekkaya A. Erman
Published: September 2011

In the paper experimental investigations aimed at allowing a detailed and accurate comparison of different FEM codes were presented and discussed. Two hollow profiles within the same die were characterized by different thicknesses within the profile, two welding chambers and critical tongues (one fully supported and one partially supported). The material flow balance was performed by means of feeder size and position on a profile and by means of bearings on the other one. Accurate monitoring of process parameters was carried out by using a self-calibrating pyrometer for profile temperature, six thermocouples for die thermal monitoring, a laser velocitymeter for profile speed and two laser sensors for die deflection on critical tongues. AA6082 alloy was used as deforming material, while H-11 hot-work tool steel was selected for the die material. The experiments were repeated at least three times under the same conditions in order to provide a nearly steady state statistical distribution of the acquired data. These are used as a reference for the 2011 edition of the extrusion benchmark.
Conditions for Sticking Friction between Aluminium Alloy AA6060 and Tool Steel in Hot Forming
Authors: Widerøe F. , Welo Togeir
Published: September 2011

The frictional conditions between an aluminium AA6060 alloy and tool steel in hot bulk forming have been investigated. The compressive-rotational method for frictional measurements, presented herein, represents an innovative approach for defining the thermo-mechanical conditions required for sticking friction at the interface between the two metals. Aluminium disks with inserted contrast material were subjected to a variety of pressures and rotated at one end at temperatures ranging from 250 °C to 500 °C. Visual inspection of the surfaces in combination with sectioning of the deformed disks formed a method for studying how different factors affect a stick-slip criterion in metal forming. It was found that the normal contact pressure required for sticking to occur was strongly dependent on the instantaneous temperature. When comparing the normal contact pressure q with the characteristic shear strength k of the aluminium alloy, q/k > 0.6 yielded sticking friction for temperatures above 300 °C, while a ratio of 0.7 was required for the lower temperatures.
Numerical Investigations of Welding Conditions during Extrusion of 2024 Alloy through Porthole Dies
Authors: Lesniak Dariusz , Rękas Artur , Libura W. , Zasadziński Józef
Published: September 2011

In the work, numerical calculations of extrusion process of 2024 alloy through porthole dies were performed. The DEFORM 3D program based on Finite Element Method was used. The way of metal flow, distributions of stresses as well as temperature level within the welding chamber were predicted for different geometry of porthole die. Particularly, different height, width, and shape of the welding chamber were adopted in calculations. The calculations allowed predicting both hydrostatic pressure and temperature levels as well their distributions in the welding region providing the best welding conditions for the alloy tested.
Design and Experimental Verification during Extrusion of Square Sections from Round Billets through Curved Dies
Authors: Rout Akshaya Kumar , Maity Kali Pada , Parida Manoja Kumar
Published: September 2011

Extrusion is one of the widely used metal forming processes. The extrusion process is carried out conventionally using a shear faced die, but shear faced dies have many practical problems such as a dead metal zone, more redundant work. In the present investigation, the evolution of uniform microstructure in extruded product with improved mechanical properties for quality products to get dimensional accuracy. A mathematically contoured non-linear converging die has been designed for extrusion of square section from round billet. CAD models of die profile have also been developed. The experiments have been conducted to verify the proposed theoretical model. The extrusion test rigs have been fabricated to carry out extrusion through mathematically contoured dies.
Simulation of the Grain Structure Evolution of a Mg-Al-Ca-Based Alloy during Hot Extrusion Using the Cellular Automation Method
Authors: Li L. , He F. , Liu X. , Lou Yan , Zhou Jie , Duczczyk Jurek
Published: September 2011

In the present study, the evolution of the grain structure of a Mg-Al-Ca-based alloy during hot extrusion was simulated with the cellular automation method. The Laasraoui-Jonas microstructure model was used to describe the dislocation evolution inside crystallites during dynamic recrystallization. The parameters in the Laasraoui-Jonas model, such as the hardening parameter, recovery parameter and material constants, were determined from the flow stress-strain data obtained from hot compression tests using a Gleeble-1500 thermomechanical simulator. The extrusion process was simulated using a DEFORM 3D FEM code. The influence of ram speed on grain structure evolution was analyzed. It was found that the average grain size increases with increasing ram speed. Good agreements between the predicted and observed grain structures were achieved.
Ballistic Performance of TiC-TiB2 Composite Armour under the Impact of Long-Rod Tungsten Alloy Projectiles of 1.4 Km·s-1
Authors: Huang Xue Gang , Zhao Zhong Min , Zhang Long , Yin Chun
Published: September 2011

Based on preparing TiC-40mol%TiB2 composite by combustion synthesis under high gravity, the ballistic targets with different-thickness ceramic tiles were achieved by lateral, cover and back confinements of shrink-fit steel. Ballistic testing showed that as the thickness of ceramic tile was smaller than 12 mm, the penetration of the ceramic tile was mainly controlled by the combination of the initial-shock and steady-state penetration, resulting in poor ballistic performance of the ceramic. As the thickness of ceramic tile was larger than 12 mm, the penetration of the ceramic tile was controlled by the combination of steady-state and third-stage (projectile deceleration and erosion acceleration) penetration, resulting in improved ballistic performance of the ceramic.
Synergistic Effect of Cr-Doped DLC Coatings and Lubricant Additives
Authors: Sun Jian , Zhang Wei , Fu Zhi Qiang , Wang Cheng Biao , Yue Wen , Peng Zhi Jian , Yu Xiang , Lin Song Sheng , Dai Ming Jiang
Published: September 2011

The combination of diamond-like carbon (DLC) coatings and fluid lubrication is an efficacious method to improve the performance and service life of the friction-pairs working under the severe conditions, but the synergistic effect of DLC coatings and lubricant additives have not been clearly unveiled. The synergistic effect of Cr-doped DLC coatings with different Cr content and the lubricant additives of ZDDP, MoDTC, and T307 on the wear of DLC-coated stainless steel sample was studied, and it was found that the wear resistance of DLC-coated stainless steel sample can be further improve by the combination of DLC coatings and fluid lubrication; doping DLC coatings with Cr at an optimum level is beneficial for the wear resistance of DLC-coated stainless steel sample lubricated by PAO, PAO+ZDDP or PAO + MoDTC, but DLC coatings with a moderate Cr content is harmful to the wear resistance of DLC-coated stainless steel sample lubricated by PAO+T307. The synergistic effect of T307 and undoped DLC coatings or Cr-doped DLC coatings with a Cr content of 23.3 % is the best, while the three studied lubricant additives are harmful for the wear resistance of DLC coatings with a Cr content of 2.4 %.
Preparation and Characterization of Nano-Films Materials
Authors: Li Cai Xia , Lv Qing , Song Jie , Jiang Dan Yu , Li Qiang
Published: September 2011

Nano-sheets are two-dimensional sheet materials exfoliated from the inorganic layered compounds by various physical and chemical methods. Their unique characteristics insertion reaction and excellent physical and chemical properties have attracted more and more researchers' widespread interests. Selecting quartz glass as the substrate, using layer by layer self-assembly technology, different nano-films materials are prepared. UV/Vis spectroscopy confirmed nano-films materials have been successfully assembled using LBL self-assembly technique. Raman spectrum are mainly used to analyze and characterize the structure of nano-films materials.
Anisotropic Permittivity Measurement of Layered Inorganic Compounds
Authors: Wu Hong Ya , Zhou Ji
Published: September 2011

The anisotropic permittivity of fluorophlogopite and biotite was measured as a function of frequency in directions along and perpendicular to the cleavage planes. The measurements were performed using an impedance analyzer in the frequency range between 0.01MHz and 10MHz at room temperature. Micas showed anisotropic dielectric properties and the anisotropy of biotite was stronger than fluorophlogopite. The permittivity reduced with the increase of frequency. These properties depended on the structure, composition and defects of micas.
Laboratory Testing of Piezoelectric Bridge Transducers for Asphalt Pavement Energy Harvesting
Authors: Yao Ling , Zhao Hong Duo , Dong Zhan Yu , Sun Yi Fan , Gao Yuan Fa
Published: September 2011

This paper presents the test results of the energy converting efficiency of piezoelectric Bridge transducer for harvesting stress driven energy in asphalt pavement. The arc and the trapezoidal Bridge transducer were made for performance comparison. The Bridge transducers were tested by Universal Testing Machine (UTM) under different frequencies and distributed load. The output voltage was recorded by digital storage oscillograph. 4 groups of data were obtained. The maximum output voltage of 232V was recorded from the arc Bridge transducer in the initial laboratory test, which was conducted under 0.4 MPa with 5 Hz half-sine loads. However, only 106V maximum output voltage was measured from the trapezoidal Bridge transducer under the same load and 154V was measured under 0.7 MPa with 5Hz half-sine loads. The results show the possibility of harvesting energy from pavement. Higher energy converting efficiency of arc Bridge transducer was measured compared to the trapezoidal Bridge transducer.
Preparation and Characterization of BiFeO3 Film via Sol-Gel Spin-Coating Process
Authors: Qi Xi Wei , Zhang Xiao Yan , Wang Xuan , Sun Hai Bin , Qi Jian Quan
Published: September 2011

BiFeO3 thin films were spin-coated on conductive indium tin oxide (ITO)/glass substrates by a simple sol-gel possess annealed at 470-590°C. The crystal structure of as-prepared BiFeO3 thin films annealed at different temperature was determined to be rhombohedral of R3m space and free of secondary phases was also confirmed. Cross section scanning electron microscope (SEM) pictures revealed that the thickness of BiFeO3 thin film was about 320 nm. The double remanent polarization 2Pr of BiFeO3 thin film annealed at 500°C is 2.5 μC/cm2 without applied field at room temperature. Image of atomic force microscopy indicated that the root-mean-square surface roughness value of BiFeO3 thin film was 6.13 nm.
Electrical Characteristics and Microstructures of Eu2O3-Doped Bi4Ti3O12 Ceramics
Authors: Chen Min , Mei X.A. , Liu J. G. , Liu J. , Huang Chong Qing
Published: September 2011

The electrical properties of Eu-doped bismuth titanate，Bi4-xEuxTi3O12(BET) ceramics prepared by a conventional electroceramic technique were investigated. XRD analyses revealed Bi-layered perovskite structure in all samples. SEM micrographs showed randomly oriented and plate-like morphology. For the samples with x=0.4 and 1.0 the current-voltage characteristics exhibited negative differential resistance behaviors and their P-V hysteresis loops were characterized by large leakage current, whereas for the samples with x=0.6 and 0.8 the current-voltage characteristics showed simple ohmic behaviors and their P-E hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization ( Pr) and coercive field (Ec) of the BST ceramic with x=0.8 were above 16μC/cm2and 70KV/cm , respectively.
Preparation and Characterization of Textured CaBi4-XLaXTi4O15 Ceramics
Authors: Jin Guo Xi , Wu Xiao Bo , Chen Ling Di , Tang Yan Xue , Jiang Ben Xue , Pan Yu Bai , Sun Da Zhi
Published: September 2011

La3+ doped textured ceramics CaBi4-xLaxTi4O15were prepared by oriented consolidation of anisometric particle method with tape casting. The orientation was improved by modifying sintering temperature. The doping of La3+in orientated CaBi4-xLaxTi4O15ceramics increased the dielectric constant. The higher dielectric constant was obtained in the direction which tropism parallels to the electric field. The relationship between dielectric constant and orientation was discussed.
Negative Resistance Behavior of Ferroelectric Bismuth Titanate Ceramics at Low Field
Authors: Mei X.A. , Chen M. , Liu R. F. , Sun Y.H. , Liu J.
Published: September 2011

Ferroelectric Bi4Ti3O12ceramics are fabricated by conventional solid-state reaction process. The current-voltage characteristic of Bi4Ti3O12sample exhibits a voltage-controlled negative differential resistance behavior at low field (E≤100V/mm), and an obvious PTC effect appears at around 100°C on the resistance-temperature curve. Based on conducting filament model about electrical transport, instead of Heywang-Jonker model, the experimental results of Bi4Ti3O12ceramics are suitably explained.
Grain Growth in (Ga, Mn)-Codoped ZnO Ceramics
Authors: Shen Bing , Wang Hua , Li Shuai , Gong Jiang Hong
Published: September 2011

Grain growth in Ga2O3and MnO co-doped ZnO was investigated for sintering from 950° to 1250°C in air. Microstructural observation revealed that the samples sintered at lower temperatures consist of uniform equiaxed grains while the samples sintered at higher temperatures consist of plat-like grains, implying that the grain growth mechanism for the examined ZnO ceramics changes when the sintering temperature increases above about 1150°C. The traditional kinetic grain growth equation was employed to analyze the variation of grain size with sintering temperature and sintering holding time. It was shown that the grain growth exponent,n, increases from 2.17 for samples with uniform equiaxed grain structure to 4.30 for samples with plate like grain structure, while the apparent activation energy,Q, increases from 237 kJ/mol for low-temperature-sintered sample to 405 kJ/mol for high-temperature-sintered samples. The increases in bothnandQwere mainly attributed to the difference between the grain morphologies in low- and high-temperature ranges. The underestimation of the sizes of the plate-like grains was also considered to be another important origin for the higher values ofnandQfor the high-temperature-sintered samples.
Synthesis, Structure and Properties of Super Fine Zn2SnO4
Authors: Song Jie , Li Cai Xia , Jiang Dan Yu , Xia Jin Feng , Li Qiang
Published: September 2011

In this paper, super fine Zn2SnO4 powder was synthesized by mechanochemical method starting from ZnO and SnO2. The structure, size and morphology of Zn2SnO4were explored with X-ray diffraction (XRD), scanning electron microscopy (SEM) and nitrogen sorption analysis with the Brunauer-Emmett-Teller (BET) method. The result showed that pure spinel Zn2SnO4 powder was prepared after 2h grinding with 3.0KW of power and the particle size was about 200 nm. The degradation experiment of organic dye was performed by the photocatalytic methods on the light of wavelength (= 365nm). The powder can degrade Alizarin red solution close to 90% under U-V light with a 9W high.
Preparation and Magnetic Properties of α-MnO2 Nanoparticles
Authors: Zhu Bao Ling , Qiherima  , Lv Li , Wang Xiao Jing
Published: September 2011

α-MnO2 nanoparticles with the average size about 22-29 nm were synthesized by hydro- thermal method. The as-synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform-Infrared Rediation (FT-IR) and thermogravimetric-differential thermal analysis (TG- DTA). We find that the average particle size of α-MnO2 is increased with the reaction temperature increasing. The diluent reactant is beneficial for the growth of α-MnO2. The smaller the molar ratio of K/Mn is, the more stable α-MnO2 phase is. The Neel temperature (TN) of nano-α-MnO2 is 5.0K obtained by the magnetic susceptibility determination, lower then the value of 24.5K for MnO2 single crystal phase. The magnetic hysteresis loop can be observed obviously at T = 5.0 K. It indicated that when the particles are at the level of nano-size level, the anti-ferromagnetic MnO2 showed the ferromagnetic nature at the lower temperature. When the temperature is high up to 60.0K, the magnetic hysteresis loop can't be observed. While when the temperature is at 120.0K, a straight line of magnetic hysteresis loop is obtained, indicating the paramagnetic magnetic nature of our sample.
Low-Temperature Synthesis and Gas Sensing Properties of Anatase TiO2 Thin Films
Authors: Ren Fu Jian , Sun Yi , Huang Liang , Ling Yun Han , Feng Jia You
Published: September 2011

Crystalline anatase TiO2thin films were obtained on glass substrates at 60°C, 75°C and 90°C, respectively, by liquid phase deposition (LPD) method without subsequent heat treatment. X-ray diffraction (XRD), atomic force microscopy (AFM) and UV-Vis spectrophotometer were used to characterize the as-synthesized TiO2thin films. The H2sensing properties of the TiO2thin films based sensors were investigated. The results show that the gas sensors signal Ra/Rg (Ra: resistance in air, Rg: resistance in a sample gas) decreases with the increasing deposition temperature. The TiO2thin films obtained at deposition temperature of 60°C exhibited the maximum H2gas response at 350°C, and the magnitude of the sensor signal and the response time for 500ppm H2was 1.25 and 17s, respectively.
Soak Colored Zirconia Ceramics and its Colorimetric Plate
Authors: Zhang Liang , Lu Huai Xiu , Shao Long Quan , Yi Yuan Fu , Deng Bin , Liu Jie , Wen Ning
Published: September 2011

Objective: To test specimens of soak-colored Vita In-Ceram YZ zirconia ceramics and the colorimetric data of staining solution colorimetric plate. Methods: five sets of specimens were prepared, soaking and coloring them with LL1 to LL5 staining solution for 2 min respectively. Specimens were sintered for 2 h at 1530°C, and grinded one side of the specimens to 1.5 mm in thickness. The colors of the specimens and staining solution colorimetric plate were tested by spectrophotometer in black background. The chromatic aberration between the specimens and colorimetric plate were calculated as well as measured the lightness difference, hue angle difference, and saturation difference. Results: the colorimetric data of the dyed specimens are L: 59.81 ~ 78.93; a: 0.36 ~ 9.36; b: 19.62 ~ 26.91. The color space of the specimens and staining solution colorimetric plate was similar and the chromatic aberration was 4.02-6.96 NBS units. The biggest difference between them was the hue angle difference, mean 7.38, followed by the saturation difference, mean 2.31; minimum lightness difference, mean 2.29. Conclusion: staining solution colorimetric plate was suitable to be colorimetric reference for the color-matching of the basic layer of the ceramic. Proper chromatic aberration leaves color revision space for the translucent porcelain veneer.
A Study on Color Stones of Clay Minerals — Changhua Stone
Authors: Chen Yan Fang , Yu Xue Hui
Published: September 2011

Changhua Stone is a rock, composed of clay minerals such as dickites and is also a special secondary quartzite formed by gas liquid metasomatic metamorphism. The article emphasizes its study on rock characteristics, mineral composition, and the causes of formation of Changhua Stone, excluding Changhua Chicken-Blood Stone. By observing petrographical characters of Changhua Stone, analyzing its physical and chemical characters, and testing its geochemical compositions with SEM and X-ray diffraction analysis, the results indicate that the mineral compositions of Changuan Stone are relate to the composition of protolith, the compositions and characters of metasomatic metasomatic fluid, and the conditions of metamorphism, especially the stress and the temperature.
Determination of Silicon Content in SiC Ceramics Precursor by Modified Titration
Authors: Yang Lu Jiao , Cheng Xuan , Zhang Ying , Liu Jia
Published: September 2011

Polycarbosilane (PCS), an important precursor for manufacture of silicon carbide (SiC) ceramics, was prepared and analyzed to determine its chemical composition. The major elements of silicon (Si) and carbon (C) in Si-C backbones and side chains in PCS represent more than 80% with minor elements of oxygen and hydrogen being less than 20%. In this work, a conventional potassium silicofluoride volumetric method was explored and modified for establishing a standard routine procedure to evaluate Si content in PCS. The optimal conditions were investigated using an orthogonal designed four-factor-three-level normal experimental scheme. The suitable parameters and standard procedure to analyze Si in PCS were obtained.
Effect of Temperature on the Phase Behaviors of Zircon by Carbothermal Reduction-Nitridation
Authors: Yin Li , Huang Zhao Hui , Xu You Guo , Li Yue Tong , Liu Yang Gai , Fang Ming Hao
Published: September 2011

Phase behaviors of zircon at different temperatures via carbothermal reduction-nitridation were investigated in this study. By using zircon as raw material, with carbon coke as reducing agent, the influence of reaction temperatures (1450, 1500, 1550 and 1600 °C, respectively) on phase behaviors and microstructure of the products was characterized by X-ray diffraction analysis (XRD), scanning electronic microscopy (SEM) and energy dispersive spectroscopy (EDS). The results shows that by carbothermal reduction-nitridation, the main phases in the final products of zircon are m-ZrO2, c-ZrO2, β-SiC, ZrN and β-Si3N4at different temperatures for 4 hours.
True Density Measurement of Refractory by AccyPyc1330 Pycnometer
Authors: Qing Huang , Zhu Jing Jing
Published: September 2011

Measuring mechanism of true density measurement of refractory through gas replacement technology by the AccyPyc1330 automatic true density analyzer was introduced. Compared with the current liquid immersion method, the gas replacement technology had many advantages in time, temperature, diversity and permeability of specimens. The results indicated that it had features of accurate data, fast measurement and less factors by the gas displacement technology.
Relationship between the Ratio of Young’s Modulus to Hardness and the Elastic Recovery of Nanoindentation
Authors: Peng Zhi Jian , Wen Tao , Gong Jiang Hong , Wang Cheng Biao , Fu Zhi Qiang , Miao He Zhuo
Published: September 2011

Through the analysis of the nanoindentation data obtained on metals, ceramics and glass, it has been confirmed that the elastic recovery during unloading cycle may be related with the material parameter H/E, and a polynomial representation which is better than the power law for the description of the unloading behavior of nanoindentation was proposed in this letter.
Permeability Characteristics of Human Dentin and a Porous Ceramic
Authors: Zhao Xin Yi , Li Ya Ping , Li Shi Bao
Published: September 2011

Objectives: To compare the permeability of human dentin and a porous ceramic with two different compositions of perfusion fluid, in vitro. Methods: Dentin discs were cut from extracted third molar at a level close to the pulp chamber and ceramic discs were cut from a porous ceramic block. The convective permeability of the discs was measured in a fluid transport model using de-ionised water or 1:3 diluted bovine serum and the hydraulic conductance was determined. Results: In the negative controls, no flow was detected. The hydraulic conductance values for the dentin discs and the ceramic discs when water was used as the perfusion fluid were 0.069±0.023and 0.047±0.019ml min-1cm-2cm H2O-1, respectively. When the discs were perfused with the diluted bovine serum the mean (standard error of the mean) hydraulic conductance values for the dentin and the ceramic discs were 0.036±0.016 and 0.012±0.0055 ml min-1cm-2cm H2O-1, respectively. Conclusion: Basing on the modern technique it is possible to fabricate discs of hydroxylapatite ceramic to act as substitutes for dentin barriers in cytotoxicity test.
Solid Particle Erosion Behavior of 3YSZ Ceramics at Elevated Temperatures
Authors: Liu Feng Jiao , Fang Ming Hao , Wang Xiao Jun , Liu Yan Gai , Huang Zhao Hui
Published: September 2011

Solid particle erosion wear behavior of 3YSZ ceramics were performed by self-designed sand blasting type high-temperature solid particle erosion wear equipment, using 36#corundum as abrasive particles. 3YSZ ceramics were pressureless sintered in air atmosphere at 1500°C for 3h. The fracture toughness and Vickers hardness could achieve 10.3 MPa•m1/2and 12.8 GPa, respectively. The effect of temperature (25°C, 400°C, 600°C, 800°C, 1000°C) and the total weight of the abrasive particles (300g, 900g, 1800g) at room temperature on the erosion wear of 3YSZ ceramic were investigated. The volume erosion rate raised and developed a nonlinear dependence on the weight of corundum abrasive particles at room temperature. The slope of the curve decreased gradually. At elevated temperature, volume erosion rate increased as the temperature went up. Nonlinear fitting presents the relationship between the volume erosion rate of 3YSZ ceramics and the corresponding temperature. Plastic deformation is the major erosion mechanism at room temperature when the weight of corundum particles was 300g and 900g. Minor chipping instead of it when the temperature grew up to 400 and 600°C or the corundum particles was as much as 1800g at 25°C. When 3YSZ targets were eroded at 800°C and 1000°C, the material removal are mainly attributed to lateral cracks for an ideally brittle material. Crack propagation is the controlling factor of volume erosion rate.
Analysis of Load-Displacement Curves of Ceramics Measured with Low-Load Vickers Hardness Test: Indentation Size Effect
Authors: Xu Bei , Gong Jiang Hong
Published: September 2011

The load-displacement curves for a series of ceramic and glass samples were recorded continuously during the low-load Vickers hardness testing. Then the hardnesses of all samples were determined by analyzing the unloading curves. It was found that all the test materials exhibit indentation size effect (ISE) similar to that observed in nanoindentation testing. The applicability of the proportional specimen resistance (PSR) model and the modified PSR model was then examined using the measured indentation data.
Experimental Study in HSM of Titanium Alloy TC4-DT
Authors: Shi Q. , He Ning , Li Liang
Published: September 2011

In this paper, a series of experiments were carried out on normal and high speed milling of a new damage-tolerant titanium alloy. The effects of milling parameters on cutting force and cutting temperature were investigated. The tool life of three commonly used cutters, such as WK10, WMG40 and WXN15, were studied. Result shows that the tool life of cutter WXN15 was the longest one when using the same flank wear VB as a standard, and cutter WK10 had a longer too life than cutter WMG40. Thus cutter WXN15 was the most suitable cutting tool to machining TC4-DT, and cutter WK10 was better than cutter WMG40.
Influences of Grinding Parameters on Forces in the Grinding of Microwave Ferrite Ceramic with Electroplated Diamond Wheel
Authors: Sun L.P. , Wang Yu Guo , Yang Yang , Yu X.R. , Lin Bin
Published: September 2011

Through the odd factor grinding experiment of microwave ferrite, the tangential and normal force were measured in different grinding parameters (wheel speed, feed rate, cutting depth, wheel size). According to the variation of the tangential force and normal force in different grinding parameters after grinding, the reasonable grinding parameters of microwave ferrite were explored. The results demonstrated that the grinding force had different variations in different grinding parameters. These could be the reference and guidance for the future processing of microwave ferrite materials.
Linear Motor Velocity and Acceleration Motion Control Study Based on PID+Velocity and Acceleration Feedforward Parameters Adjustment
Authors: Peng Wen Fang , Li Guang Hui , Wu Peng , Tan Guang Yu
Published: September 2011

This paper adopts with a PMAC Programmable Multi-axis Controller to control a linear motor through adjusting PID + velocity and acceleration feedforward parameters of the control card. The motor can reach 50-nm precision at lower speed. The PLC real-time monitoring function of the software is used to monitor the actual pace of registers. The real-time online adjustment of PID parameters of the motor at various speeds is realized, which makes the motor reach high motion accuracy at various velocity and acceleration.
Analysis on Thermal Electromotive Force of Carbide Tools
Authors: An D.W. , Chen Wu Yi
Published: September 2011

Trying to analysis the influence of the instability of carbide tool materials on cutting temperature measurement by natural thermocouples, a series of experiments calibrating the thermal emf properties of tool inserts were carried out with an improved tool-workpiece thermocouple calibration device. Four chosen types of carbide tools were examined to detect their thermal emf on their different cutting edge areas. By calculating and comparing the thermal emf waving range of them, the thermal emf stability of carbide tools and the temperature measurement error lead by it was evaluated. As the experiments result, the influence was confirmed. The thermal emf variation among the cemented carbide tools was detailed by using certain statistics processing to the experiment data.
Optimization Method of Machining Center Multi-Joint Stiffness Based on Orthogonal Experiment and FEA
Authors: Sun Ming Nan , Yin Guo Fu , Mi Liang
Published: September 2011

Machine tool joint stiffness has important affects on the dynamic characteristics of the whole machine tool. It is a challenging task to optimize multi-joint stiffness of the overall structure. By discussing the distribution of stiffness of linear guides, ball screws, bolt joints and bearings, a discrete optimization method of multi-joint stiffness of a machining center was presented based on orthogonal experiment and FEA. Mean frequency formulation was adopted to define the index of orthogonal optimization. According to the principle of orthogonal experiment, optimization levels were found out, sequence of the factors on the index of the orthogonal experiment was listed and significant factors were determined. Results of this research proved the validity and feasibility of the discrete optimization method of multi-joint stiffness of the whole machine tool by combining orthogonal experiment and FEA.
Studies on Tool Wear Monitoring Based on Cutting Force
Authors: Xiao Mao Hua , He Ning , Li Lei
Published: September 2011

On-line tool wear sensing was an important subject in the Flexible Manufacturing System. Mathematic method is applied in this paper to analyze the correlation between cutting force and tool wear, and a cutting force model was established based on the tool wear. The predicted value of cutting force was calculated through the cutting test. Predicted value by comparison with the experimental data verifies the accuracy of the cutting force model. On this basis, a new method for monitoring tool wear based on measuring cutting force was proposed.
Tool Path Planning for Five-Axis NC Machining of Implant Shaping Mold for Cranioplasty
Authors: Zhang Liang , Li J. , Lou B.C.
Published: September 2011

The necessity for skull patch surface for cranioplasty was introduced and it was divided according to maximum normal curvature in the discrete points after skull patch surface dispersed. Then the tool axis vector was determined by the lead angle of the tool, corresponding to generating the tool path in each area; At last, the implant shaping mold for cranioplasty was produced by five-axis NC machine.
CNC Linear Cutting Logarithmic Spiral Type Internal Gears Sleeve Application Research
Authors: Luo Ning , Wang Y. X.
Published: September 2011

The article studies on the processing program of Logarithmic spiral internal gears face with features of CNC linear cutting machine which can be easily used in processing complex parts to produce qualified products and to apply non-key surface connection into the production.
Development of the Thermal Error Measurement System for Machine Tool Spindle Based on Virtual Instruments Technology
Authors: Zhang Hong Jie , Gao Wei Guo , Qi X.Y. , Cui L.Y. , Zhang D.W.
Published: September 2011

Based on the virtual instruments technology, a data acquisition and pretreatment system for monitoring the thermal signals of the spindle of machine tool is suggested, and the temperature rise and thermal distortion signals are collected synchronously. The software of the system introduces Producer/Consumer pattern to improve data sharing and buffered communication between data collecting and data storage processes, by this means, data missing and iteration are avoided, although these two processes run at different rates. At mean time, Matlab Script interface technique is utilized to realize the hybrid programming of Matlab and LabVIEW, which makes the acquisition system possess the ability of accomplishing complex algorithm.
Dynamic Analysis and Optimization of Machine Tool in Consideration of Joint Parameters
Authors: Xu C. , Wu Z.J. , Zhang J.F. , Feng P.F. , Yu D.W.
Published: September 2011

This paper provides the methodology on analyzing the dynamic characteristic of machine tool in consideration of joint parameters. To ensure the dynamic model is available for further study, modal experiment for vertical machining center is involved. The machine tool is divided into several parts and connected with spring and damping for substructure modeling. Particularly, the bolt-fixed joint is an example for the joints modeling. Based on the dynamic model, simulation of modal analysis and harmonic response are carried out. Besides, method of optimization design of column and milling box is given to improve the performance, which is proved to be feasible in harmonic response.
Shifted Point Array Modeling of 3D Calibration
Authors: Ding Y.B. , Mei Jiang Ping , Zhang W.C.
Published: September 2011

An approach of calibration method for 3D sensing scheme based on shifted point array encoding is presented. Initially a 3D calibration benchmark is established in object space, the camera subsystem can be calibrated with the benchmark. The projection optics subsystem is bounded with camera subsystem in this sensing scheme so a constraint condition is imposed on both subsystems. Therefore it is possible to calibrated projection subsystem by introducing a concept of benchmark transmission. Once both subsystems have been calibrated, the 3D coordinates of range image can be obtained with moderate accuracy. The coordinate difference between measured data and prescribed benchmark is used to define a square-error based objective function, leading to a non-linear equation. By solving this equation, one is able to determine the required parameters of the system configuration. Experiment results show that, after proposed calibration procedure, the 3-D sensing scheme based on point array encoding is able to achieve such an accuracy as the standard deviation in X direction is 0.29mm, 0.24mm in Y direction, and 0.29mm in Z direction, respectively, for a measuring volume of 300×300×80mm3.
Characteristics and Formation Mechanism of Segregation During the Solidification of Aluminum Alloy with Ultrasonic Radiation
Authors: Li X.Q. , Jiang Ri Peng , Li Z.H. , Zhang L.H. , Zhang X.
Published: September 2011

An industrial experiment was carried out to study the characteristics and formation mechanism of segregation in semi-continuous direct-chill (DC) casting ofΦ300mmaluminum alloybillet with ultrasonic radiation of different powers. Results show that both microsegregation and macrosegregation of solute elements Zn, Mg, Cu are improved remarkably when ultrasonic vibration is applied to A1-Zn-Mg-Cu alloy. Meanwhile, the higher power of ultrasonic vibration is, the more homogeneous distribution of solute elements becomes, and then the more effective improvement of segregation is achieved. With a 240W ultrasonic treatment (UST), the intra-grain solution degree of elements Zn, Mg and Cu increases by 35.8%, 41.8% and 40.2% respectively while the macrosegregation ratio decreases by 10.3%, 7.4%, 6.7%. Physical and chemical effects caused by ultrasonic field exert a positive impact on the solute elements diffusion, grain refinement, the depth of sump and solution degree et al, which contribute to the improvements of segregation.
Research on Stress Corrosion Behavior of AISI304 Stainless Steel Enhanced by Ultrasonic Peening Treatment
Authors: Yin D.Q. , Wang Dong Po
Published: September 2011

Surface-strengthening treatment was performed on the welded joints and base material specimens of AISI304 austenitic stainless steel using ultrasonic peening treatment. Stress-corrosion test in a 42% boiling magnesium chloride solution were conducted with treated and untreated specimens. Four-point loaded specimens were employed in the stress-corrosion test. Residual stress in the surface layer of the specimens was analyzed with an x-ray stress analyzer before the stress corrosion test. The microstructure of the specimens was observed by a scanning electron microscope after the stress corrosion test. The state of stress in the surface layer of the specimens affected by the ultrasonic peening treatment was analyzed. The stress corrosion cracking behavior was studied by observing the corrosion fractographs. The results showed that the stress corrosion resistance of the welded joint and base material specimens was remarkably improved because of the compressive residual stress employed by the ultrasonic peening treatment. Fracture modes were of the same kinds in the treated and untreated specimens.
Conceptual Design for Upper Beam of Hydraulic Press
Authors: Yu H.B. , Li Y.C. , Zhang Chun
Published: September 2011

Conceptual design method for the upper beam of the press is proposed. Based on the technical parameters (nominal load and tablesize) and press structural scheme (number and layout of the hydraulic cylinder), simplified mechanical model of upper beam is established and then the conceptual design model is derived. According to the model, conceptual prototype with equivalent moment of inertia of the cross section is achieved. The structure prototype of upper beam is then obtained based on the conceptual prototype by introducing the design rules and experience and solving an optimization model. The method is applied to the structure prototype design of upper beam of a 100MN hydraulic press.
Study on Mapping of Forming Precision of Workpiece to Stiffness of Hydropress Frame
Authors: Yu H.B. , Li Y.C. , Zhang Chun
Published: September 2011

Determination of the stiffness specification is essential to subsequent structure design of a hydropress. Through the analysis of the press-die-workpiece system, it is found that the forming precision of the workpiece is significantly affected by the deflection of the lower beam of press frame. According to this finding, a mapping model between the forming precision of the workpiece and the stiffness of the lower beam is established. With this mapping model, the forming precision of the workpiece can be mapped into the stiffness requirement of the lower beam to form the stiffness specification of the hydropress frame.
A Survey on Electrode Materials for Electrical Discharge Machining
Authors: Zhang Li , Dong Li Hua , Wang D.S. , Fan C.H. , Zhou Y.
Published: September 2011

This work screens electrode materials used in EDM and proposes some potential electrodes for future industrial applications. Traditional graphite, W, and Mo EDM electrodes have low TWR due to their high melting points; while, Zn, brass, and Cu often experience too much tool wear. As to some newly developed alloy and composite materials, their machining performances depend on not only their melting points but also their microstructures. Cu-W alloy has high wear resistance but it is susceptible to shape loss due to its internal porosity. By contrast, Cu-graphite, Cu-ZrB2 and Cu-TiB2 composites show good capabilities of removing material with little wear loss and therefore could be promising for future usages.
Research and Application on Heterogeneous CAD Platforms of Modular Fixture System
Authors: Cai Jin , Liu H.X. , Duan G.L.
Published: September 2011

Application on multi-platforms for a computer-aided fixture design (CAFD) system is significant. But now, relative less attention is focused on this direction. On above backgrounds, research was carried out on data construction, data description, data conversation as well as data parsing. In modular fixture system, components in the modular fixture base were described according to their CSG-based primitives. So, XML was used to represent the simple data because of its widely using on net and different operational systems. By developing interfaces between diverse CAD systems, the modular fixture system can be applied on heterogeneous environments and reinventing the wheel can be avoided.