bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Coil Temperature on Microstructure and Texture Evolution of an High Strength Nb-IF Steel Sheet
Authors: Xu Yun Bo , Hou Zi Yong , Yi Hong Liang , Wu Di , Wang Guo Dong
Published: March 2013

Effect of coil temperature on the texture and microstructure evolution during cold rolling and annealing were investigated by OM, ODF and EBSD. The results indicate that the {223}<110> and {114}<110> textures appeared after cold rolling are inherited followed by annealing, whose intensities would be higher as the coil temperature decreased. Lower coil temperature could improve the uniformity of grain size and increase the fraction of low-angel grain boundaries as well as coincidence site lattice boundaries. And the {111}//ND texture is improved in the lower coil temperature cold and annealing steel sheet, which is beneficial for the deep-drawability.
Effect of Technological Parameters on Preparation of Mg-Based Foam Materials
Authors: Luo Hong Jie , Zhang Li , Xu Zheng Guo , Yang Yuan Sheng
Published: March 2013

As a novel material, Mg-based foam material not only has fantastic physical characteristics, such as low density, high specific surface area, high specific strength and stiffness, and good biocompatibility, but also has special functional properties, for example, electromagnetic wave shielding, vibration reduction, sound absorption, and so on. It can be widely applied to aeronautical and aerospace, military, shipbuilding, transportation, automotive and medical industries. Mg-based foam material was prepared by direct foaming in magnesium alloy liquid in this study, and the effect of technological parameters on the products, such as addition amount of and granularity of SiC particles and MgCO3 particles, stirring temperature, stirring time, stirring velocity, foaming temperature and foaming time, was investigated. The aim of this research was to develop a new technology which could fabricate large scale Mg-based foam material in air condition. The results showed that variations of technological parameters may affect preparation of the foam materials in some extent and resulted in the changes of the products in apparent density, porosity and structural uniformity. The light weight Mg-based foam with homogeneous pores could be obtained by suitable combination of the technological parameters.
Heat Transfer Performance of Lotus-Type Porous Copper Micro-Channel Heat Sink
Authors: Chen Hai Feng , Liu Yuan , Chen Liu Tao , Li Yan Xiang
Published: March 2013

Lotus-type porous structure is a new kind of micro-channel structure and can be used as heat sink for heat elimination of high powered electronic devices. Numerical analysis based on the simple fin model was used to predict the equivalent heat transfer coefficient of lotus-type porous copper micro-channel heat sink. Compared with the water, GaInSn working fluid could further promote the heat transfer performance of the heat sink. According to the theoretical analysis, a heat transfer coefficient as high as 14W/(cm2K) was attainable when the pressure drop was 50 KPa and an appropriate structure parameters: 0.4 mm in pore diameter, 0.4 in porosity and 4mm in height of porous copper were achieved.
The Probabilistic Safety Assessment of the Rail Mounted Gantry Cranes
Authors: Zhang Yu Bo , Li Yi Qin , Luo Hong Yun
Published: March 2013

The technology of PSA(probabilistic safety assessment) based on fracture mechanics has been applied on the engineering field. However therere few application on the port machines still with some problems. A comprehensive discuss on PSA method was presented in this paper. Firstly, the experiment of the fracture mechanics parameters of Q345 steel used on the port machines structures was made to provide the parameters for PSA. Secondly, probabilistic analysis with the series of the Q345 steels FAC(Failure Assessment Curve) provides the PSA criterion. By using stress analysis, defect detection and material properties, the structures safety of a RMG(Rail Mounted Gantry) of one port in service were assessed, the result show that the key points of the crane are safe in one point service. The technology presented in this paper will be significant for the operation and management of the port equipment.
The Effect of the Size and Electronic Factor on Occupation and Magnetic Property of Co Addition in L10 FePt Alloy
Authors: Shu Xiao Lin , Jia Yong Fei , Chen Zi Yu
Published: March 2013

The size and the electronic factor are used to analyze the occupation of doped Co atom in L10 FePt alloy as well as its influence on crystal structure and magnetic property. The Co atom located in Fe sublattice site is determined by the variance of the calculated structure and the doping energy results investigated by the first-principles calculations. The charge-density difference contour plot and Bader charge analysis can quantitatively distinguish the effects of the size and the electronic factor on physical properties of the doping alloy. The effect of the electronic factor on the doping energy is more dominant than that of the size factor. The size factor almost has no effect on saturation magnetization.
First-Principles Study on the Thermodynamic Properties of Nb, Cr2Nb and Nb5Si3 Alloys
Authors: Yang Zeng Qian , Shang Jia Xiang
Published: March 2013

Nb-Si-Cr alloys have shown great potential as the aviation materials because of their good mechanical properties and high temperature oxidation resistance. The thermodynamic properties of Nb, Cr2Nb, α-Nb5Si3, β-Nb5Si3, as the main constituent phases of Nb-Si-Cr alloys, were calculated by first-principles methods combined with quasi-harmonic Debye model. The calculated results are in agreement with available experimental data. Compared the thermo-dynamic properties of different phases, it is found that the thermal expansions of these phases are similar and have the same trend with change of temperature. Thermal expansion coefficient of these phases are dependent with increases with temperature and decreases with pressure, respectively, while the bulk moduli decreases with increasing temperature. At last, the micro stress created by the differences in coefficients of thermal expansion between Nb and Cr2Nb upon cooling was evaluated. The result showed that the stress is too small to cause cracking at the interface between Nb and Cr2Nb.
Research on Flow Behavior of Advanced High Strength Steel at Elevated Temperature
Authors: Lei Cheng Xi , Cui Jun Jia , Xing Zhong Wen , Zhao Hao
Published: March 2013

Tensile experiments were carried out on advanced high strength steel (AHSS) by the test machine Gleeble3500, under the temperature ranging from 650 to 850 and the strain rate of 0.1/s~5/s, and the corresponding stress-strain curves were obtained. The peak stress level decreases with the increasing of deformation temperature or the decreasing of strain rate, which can be represented by a ZenerHollomon parameter in a linear equation. A revised model describing the relationships between the peak stress, strain rate and temperature of advanced high strength steel at elevated temperatures was proposed by compensation of strain and strain rate. The comparison of the predicted and experimental results of stressstrain curve can prove the good predictive power of the model, the Adj. R-Square between the peak stress and the linear equation was reached to 0.97.
Simulation and Technology Optimization for Rolling Web Wave of Large Size H-Beam
Authors: Guo Xing Ye , Zhu Guo Ming , Kang Yong Lin
Published: March 2013

The rolling process of large size H-Beam NH800×300 in multiple working conditions was simulated by using of commercial finite element method software LS-DYNA. the web wave emerged during rolling of H-Beam was specially demonstrated. The main factor which affected the rolling force during the rolling process has been illustrated. The rolling process under the condition of different horizontal roller radius, different friction coefficient and flange/web stretching ratio were numerically simulated. By means of simulation with different flange/web stretching ratio, it could be concluded that the crucial situation to generate the rolling web wave in typical rolling pass is that the flange/web stretching ratio is about lower than 0.93, which may cause the web unstable and the rolling wave.
Prediction and Simulation of Microstructure-Property and Residual Stress for Large Size Hot Rolled H-Beam
Authors: Zhu Guo Ming , Kang Yong Lin , Guo Xing Ye
Published: March 2013

Based on the full process 3D elastic-plastic thermal mechanical coupled simulation of large size H-Beam, the relevant issues about the residual stress distribution of H-Beam has been systematically analyzed, which include the formation and control of residual stress. In addition, based on the conclusion of the large size H-Beam residual stress analysis, the method of cooling for the control of residual stress has been provided and experiments about the outside cooling of the flange has been implemented. The result of the experiments proved that the coercive water cooling for the outside surface of flange largely reduced the residual stress of the web, which can avoid the web wave after cooling and crack phenomenon during utility. At the same time, on the basis of the whole rolling process finite element simulations, with the help of model of austenite evolution, phase transition and microstructure and property prediction, the simulation of 3D microstructure evolution and property prediction has been fulfilled. By means of microstructure research, it has been proved that the simulation result meet the genuine microstructure very well, which has revealed the feasibility of this method.
Development of Thermodynamic Database of Ti-V-Based Hydrogen Storage Alloys
Authors: Wang Jiang , Rong Mao Hua , Tang Cheng Ying , Rao Guang Hui , Zhou Huai Ying
Published: March 2013

In this work,Ti-V-based hydrogen storage alloys have been studied because of their high hydrogen absorption/desorption capacities and good activated properties. Experimental data of phase equlibria and thermodynamic assessments of the sub-binary/ternary systems in the Ti-V-based multi-component systems are reviewed in reported literature. Based on the measured phase diagram data and thermochemica information, thermodynamic parameters formulating the Gibbs energies of various phases in some sub-binary/ternary systems of Ti-V-based multi-component alloys are assessed using the CALPHAD method. A set-consistent thermodynamic database of the Ti-V-based multi-component system is developed, which is helpful to study the relations between alloy compositions, microstructure and hydrogen storage properties in order to design novel Ti-V-based hydrogen storage alloys.
Formation Sequence of Interface Intermetallic Phases of Cold Rolling Cu/Al Clad Metal Sheet in Annealing Process
Authors: Yang Lin , Mi Bing Xue , Lv Lin , Huang Hong Jun , Lin Xiao Ping , Yuan Xiao Guang
Published: March 2013

The formation Gibbs energy of the intermetallic phases at the interface of cold rolling Cu/Al clad metal sheet in annealing process was calculated theoretically. The concept and the calculating method of effective formation Gibbs energy which can predict the formation sequence was proposed. By the means of that theory, the calculated formation sequence of the intermetallic phases at 200-300 was worked out for the cold rolling Cu/Al clad metal sheet in annealing process, i.e. Al2Cu (Al side), AlCu (mid-layer) and Al4Cu9(Cu side). Besides, the boundary layer organizational microstructure of the composite material was analyzed by the means of SEM and XRD. As a result, the annealing temperature is the primary factor which affects the formation of the intermetallic phases of the cold rolling Cu/Al clad metal sheet, while the holding time is the second one. The observed formation sequence of the intermetallic phases of cold rolling Cu/Al clad metal sheet on annealing temperature 250-300 was: Al2Cu (Al side), Al4Cu9(Cu side) and AlCu (mid-side).
Galvanic Corrosion between Depleted Uranium and 45 Steel
Authors: Pu Zhen , Wang Qing Fu , Shuai Mao Bin , Lang Ding Mu
Published: March 2013

Self-corrosion and galvanic corrosion of depleted uranium and 45 steel were studied by electrochemical analyzing technologies. Corrosion products were analyzed by Energy-dispersive spectroscopy (EDS). The results showed that, in the 3.5wt.%NaCl solution, DU acted as anode with an accelerated corrosion rate, and 45 steel acted as cathode during the process of galvanic corrosion for DU/45 couple. The galvanic potential and current density of the DU/45 couple were around-770mV and 12.5μA/cm-2, respectively.
Research on Dieless Drawing Process of Stainless Steel Tapered Tube
Authors: Liu Xue Feng , Zhang Ye , Qin Fang , Mao Hao En , Xie Jian Xin
Published: March 2013

The traditional forming technologies of stainless steel tapered tube have some disadvantages, such as its complicated processes, few product specification, low production efficiency and high production cost. Dieless drawing is a new kind of near net-shaping process for fabricating tapered metallic tubes with large deformation per pass, high yield ratio of material and flexible production. Dieless drawing of stainless steel tapered tube was studied systematically in order to establish both temperature field model with respect to the changes of boundary condition and metal flow velocity during deformation, and a drawing speed controlling model with respect to the volume change of deformation zone. The models were verified by experiments in the present investigation. Finally, a continuous pickling process with variable-speed was proposed for tapered metallic tube, which was successfully applied to surface oxidation film removal of the stainless steel tapered tube.
Fatigue Fracture of Clay Reinforced Nylon Nanocomposites
Authors: Kodama Yusuke , Zhu Shi Jie , Nakahara Yukiko , Usuki Arimitsu , Kato Makoto
Published: March 2013

Nylon 6 clay hybrid (NCH) composite consists of nano-sized Montmorillonite and nylon 6 matrix. The testing materials were nylon 6, NCH-2 (2 wt% clay reinforced composite) and NCH-5 (5 wt% clay reinforced composite). Fatigue tests at the glass transition temperatures (35 °C and 50 °C) were performed with a stress ratio of 0.1 and frequency of 0.1Hz. NCH-2 had the highest fatigue strength at room temperature, but NCH-5 had the highest fatigue strengths at 35 °C and 50 °C. It was found that the fracture origin changed from surfaces to interior of specimens with an increase in temperature in NCH-2 and NCH-5.
FEM Analysis on Thermoelectric Properties of Metal/TiO2–x Composites with Random Distribution of Metal Powder
Authors: Sagara Katsuhiro , Lu Yun , Luan Dao Cheng
Published: March 2013

Analysis model of finite element method with a random distribution for thermoelectric composites was built. Thermoelectric properties including electrical resistivity, Seebeck coefficient and thermal conductivity of M/TiO2–x (M = Cu, Ni, 304 stainless steel (304SS)) thermoelectric composites were investigated by the proposed model. Cu/TiO2–x composite showed a large decrease in electrical resistivity while 304SS/TiO2–x composite thermal conductivity was slightly increased. Calculated dimensionless figure-of-merit, ZT of Ni/TiO2–x composite was higher than those of TiO2–x and the other composites in a wide range of metal volume fractions because Ni has large absolute values of Seebeck coefficient, power factor and dimensionless figure-of-merit compared to the other two metals. It was found that power factor and dimensionless figure-of-merit of thermoelectric composites depended on the balance among electrical resistivity, thermal conductivity and Seebeck coefficient. The results revealed that it is important for M/TiO2–x composites to choose suitable addition metal with high power factor and dimensionless figure-of-merit.
Comparison of Mechanical Properties of a Biomedical β Titanium Alloy Added with Pure Rare Earth and Rare Earth Oxides
Authors: Song Xiu , Wang Lei , Niinomi Mitsuo , Nakai Masaaki , Liu Yang , Zhu Miao Yong
Published: March 2013

The microstructures and fatigue properties of the TNTZ added with Y or Y2O3 have been investigated. The results indicate that TNTZ added with Y or Y2O3 are all found to be composed of β phase and the small amount of Y2O3. The grain size of TNTZ added with Y or Y2O3 is smaller than that of TNTZ. The Young’s modulus of TNTZ added with Y or Y2O3 are maintained at a low level, and Young’s modulus of TNTZ added with Y is smaller than that of TNTZ added with Y2O3. The mechanical properties are both improved by adding Y or Y2O3, while the tensile strength of TNTZ added with Y2O3 is slightly higher than that added with Y. The high cycle fatigue limit of the alloys added with Y or Y2O3 are similar, while the low cycle fatigue strength of TNTZ added with Y is higher than that added with Y2O3. The improvement in fatigue properties ascribes to the microstructure refinement and the pining effect of Y2O3 particles. On the other hand, Y elements form Y2O3 with the Oxygen elements in the matrix, thus lead to the weakening of the Oxygen solution effect.
Mapping of Phase Distribution in Electron Holography with a Stage-Scanning System
Authors: Lei Dan , Mitsuishi Kazutaka , Harada Ken , Shimojo Masayuki , Ju Dong Ying , Takeguchi Masaki
Published: March 2013

A new method is proposed for mapping of phase distribution in electron holography. A stage-scanning system was used for moving the specimen to obtain a series of holograms with different specimen positions in a fixed electron-optics configuration. By applying a digital aperture which selects an area on holograms with different specimen positions, an interferogram of the specimen can be obtained directly without a complex reconstruction method such as the one using Fourier transformation. Experimental results for a Co particle demonstrated the practicability of this method.
Investigation of Bonding Interface and Strength Properties in Diffusion Bonding of MgAZ31/Al6061
Authors: Zhao Ming , Ju Dong Ying
Published: March 2013

This paper is mainly a study the diffusion bonding of Mg-AZ31/Al-6061 by using the direct bonding method. After bonding process, multilayer field with Mg-Zn and Al-Zn have been confirmed by EPMA determination. Through the microstructure observed by SEM, bonding boundaries of Mg-AZ31/Al-6061 had good diffusion formation. The identification of the component on near interface was measured by XRD method. By using of these results, the mechanism of the magnesium alloy and aluminum alloys was discussed.
Study on Anisotropic Mechanical Behavior at near Pre-Crack for AZ31B Sheet under Biaxial Stress
Authors: Wang Jian Gang , Ju Dong Ying , Yin F.X. , Mao Lei
Published: March 2013

In this study, a biaxial tensile test of cruciform specimens containing centre notch was conducted in order to clarify the deformation behavior near the crack tip at the early stages of crack initiation when objected to a biaxial stress state. Results show that the hardness and stress value within the deformed zone increased with increase in the loading ratio. Observation of the microstructure reveals that the deformation is dominated by basal slip under equal biaxial tensile loading. The asymmetrical biaxial tensile loading generates deformation twins near the crack tip. These results indicate that existing deformation twins contribute to higher hardness, and there is obvious anisotropism in the vicinity of crack tip under asymmetrical biaxial tensile loading.
Effects of Slit Patterns on the Tensile Properties of Unidirectionally Arrayed Chopped Strands Composites
Authors: Li Hang , Wang Wen Xue , Takao Yoshihiro , Matsubara Terutake
Published: March 2013

This study investigates the tensile properties of UACS (unidirectional arrayed chopped strands) laminates with different slit patterns. UACS composite is a kind of short fiber reinforced polymer by introducing slits into prepregs before the fabrication of laminates. Existing UACS composites have superior flowability but relatively low tensile strength compared to conventional CFRP (carbon fiber reinforced polymer). Consequently, many efforts have been made to improve the strength of UACS composites. In this study, two new discontinuous slit patterns, staggered pattern and bi-angled pattern, have been developed. Tensile tests reveal that two new UACS laminates with staggered and bi-angled slit patterns have higher strength and higher stiffness than existing UACS laminates with continuous slits. Discontinuity of slits plays an important role in inhibiting the development of delamination. Different slit patterns show different failure modes.
Effect of Substrate on Crystallization of Sol-Gel-Derived Pb(Zr0.52Ti0.48)O3 Thin Films by Microwave Annealing
Authors: Wang Zhan Jie , Chen Yan Na
Published: March 2013

Amorphous Pb(Zr0.52Ti0.48)O3 (PZT) thin films were deposited on LNO/SiO2/Si and Pt/Ti/SiO2/Si substrates by a sol-gel method and then crystallized by microwave irradiation in the microwave magnetic field. The crystalline phases and microstructures as well as ferroelectric property of the PZT films were investigated, and the effect of substrate on crystallization of PZT thin films heated by microwave annealing was discussed. The PZT films on LNO/SiO2/Si substrate show a highly (100)-preferred orientation, and better ferroelectric property than those on Pt/Ti/SiO2/Si substrate. The results demonstrated that LNO/SiO2/Si substrate is advantage for annealing of PZT thin films by microwave irradiation in the microwave magnetic field.
Effect of Dry-Ice Blasting on the Microstructure and Properties of Plasma-Sprayed CoNiCrAlY Coating
Authors: Dong Shu Juan , Song Bo , Hansz Bernard , Liao Han Lin , Coddet Christian
Published: March 2013

Depending on the oxidation extent and the surface roughness after coating manufacturing, CoNiCrAlY coating displays different performance in thermal barrier coating systems. In this study, plasma-sprayed CoNiCrAlY coatings were treated by dry-ice blasting. Various treatment approaches of dry-ice blasting were assessed by means of comparing the coating quality in terms of cross-sectional structure, oxide concentration, surface morphology and roughness, and microhardness. The results showed that CoNiCrAlY coating including decreased oxides and smoother internal texture can be obtained in comparison with that deposited by conventional APS, no matter what type of treatment. The oxidation content differ after using different jet angle and installation location of dry-ice blasting. To some extent, dry-ice blasting has some cleaning effect on those splashed particles. However, no much change can be recognized in the top-surface morpholgy and surface roughness, because of the relatively small hardness of dry-ice pellets. There is a slight decrease in hardness probably resulting from the decrease in the oxide.
Residual Stress in Oxide on NiCrAlY Coating Evaluated by Photoluminescence Spectroscope
Authors: Wang Hai Qiang , Osaki Takeshi , Nakahara Yukiko , Zhu Shi Jie
Published: March 2013

The purpose of this study was to understand the effects of thermal exposure temperature on residual stress in thermal grown oxide (TGO) on NiCrAlY coating. The residual stresses in the TGO layer were measured by photo-stimulated luminescence spectrum. High velocity oxygen fuel sprayed (HVOF) method was used to fabricate NiCrAlY coating material. The thermal exposure tests were conducted in air at 900°C, 1000°C, 1100°C for up to 1000 hours using an electric furnace. It was shown that the thickness of the TGO increases with an increase in thermal exposure time with a parabolic curve. The residual stress in the TGO layer increases in thermal exposure time up to 75 hours, and then, the residual stress in the TGO layer decreases slowly. The effects of surface roughness on the residual stress in the TGO were discussed based on experimental results and analysis.
Glass-Forming Ability and Mechanical Properties of Zr-Ni-Al Bulk Metallic Glasses with High Zr Content
Authors: Li Yan Hui , Zhang Wei , Dong Chuang , Makino Akihiro
Published: March 2013

The thermal stability and glass-forming ability (GFA) of Zr70Ni30−xAlx (x = 5 − 19) metallic alloys were investigated. Alloy with x = 8 has the largest critical diameter (dc) of 2 mm in the alloy series, which possesses the largest supercooled liquid region, Trg and γ value, simultaneously. Further addition of 2 − 4 at.% Nb to Zr70Ni22Al8 alloy by replacement of Zr increases the dc up to 6 mm. In addition, Zr70Ni22Al8 bulk metallic glass exhibits large compressive plastic strain of 13.8% with yielding stress of 1547 MPa and Young’s modulus of 79 GPa. Addition of Nb increases the strength but lowers the plasticity.
Preparation of Ni-P-Al2O3 Composite Film on Mild Steel with High Resistance to Corrosion and Wear
Authors: Wang Rong Guang , Sawada Hiroki , Wang Nan , Nie Jian
Published: March 2013

The Ni-P-Al2O3 composite film was coated on mild steel of SS400 with electroless plating method. In this process, different sizes of Al2O3 particles and different blended amounts of Al2O3 particles into the plating solution were applied. From the surface and cross section observation, it is known that the Al2O3 particles were uniformly dispersed in the Ni-P alloy. The highest corrosion resistance and the highest wear resistance of the Ni-P-Al2O3 composite film were obtained when adding Al2O3 particles with the mean diameter of 0.05μm into the plating solution at the blended amount of 1.0g/L.
A Developing Method to Prepare Micro-Nanopowder by Incorporating Jet Milling and Electrostatic Dispersion
Authors: Zhang Rong , Yin Peng Fei , Liu Qian , Zhou Ting , Hu Jiang Chang , Li Yi Bing
Published: March 2013

A new method to prepare micro-nanopowder with incorporating jet milling and electrostatic dispersion was presented in this study. The dispersivity of the powder could be improved during the process of jet milling by having the particles charged with identical charge. Both micro-nanopowders with high dispersion, calcium carbonate (CaCO3) and magnesium zinc ferrite (MgZnF) were prepared respectively. The theoretic studies on this method and the analyses on the effects of preparation parameters on dispersivity, showed that jet milling /electrostatic dispersion (J/E) method to prepare micro-nanopowder in the air without any additive is achievable. The charge voltage and air current pressure would strongly affect the characters of the powder. The charge to mass ratio (q/m) of both powders reached its peak under the charge voltage at 50 kV and air current pressure at 0.3MPa.
Effect of Nanosized Particles on the Mechanical Properties of Y2O3
Authors: Razavi Khosroshahi Hadi , Liu Xin , Saito Noritaka , Nakashima Kunihiko , Kaneko Kenji
Published: March 2013

A systematic series of experiments was performed to determine the optimum firing schedule of Y2O3. A two-step sintering with subsequent profile succeeded to fabricate Y2O3 ceramic with the relative density of 97.6% and the average grain size of 0.46 μm: first step and second step temperature of T1 = 1490 °C and T2 = 1350 °C, respectively and second step holding time of t2 = 20 h. After the firing schedule of pure Y2O3 was determined, two types of TiO2/Y2O3 and ZrO2/Y2O3 composites were fabricated for the further improvement of mechanical properties. According to results, ZrO2/Y2O3 composite showed a dramatic increase in strength and toughness as 417 MPa and 4.4 MPa.m1/2, respectively.
Electrochemical Behavior of AZ Magnesium Alloy Containing Rare Earth Element
Authors: Gu Ting Ting , Xia Hong Qi , Liu Li Xin , Liu Jing , Qi Ting , Zhao Hong Yang , Fang Zhi Gang
Published: March 2013

The electrochemical behavior of a new magnesium alloy (AZ61) containing rare earth elements-cerium (Mg-Al-Zn-Mn-Ce alloys) was investigated in 3% NaCl electrolyte using electrochemical methods such as linear sweep voltammetry, Tafel curves and electrochemical impedance spectroscopy. Scanning electron microscopy was used to characterize the surface morphologies of magnesium and its alloys. The results shows that compared with that of the most commonly used Mg alloy–AZ61, the cerium containing magnesium alloy exhibited higher electrochemical activity, and higher corrosion resistance. The electrochemical activity of Mg-Al-Zn-Mn-Ce was higher than that of Mg and Mg-Al-Zn-Mn-Ce alloys in 3% NaCl. The corrosion resistive order decreased in the following sequence: Mg-Al-Zn-Mn-Ce > Mg-Al-Zn-Mn > Mg. The electrolytes favored anodic magnesium oxidation, but the alloying element of Ce facilitated the formation of dense passive films on alloy surfaces.
Improvement of Catalytic Activity of Atomized Ni3Al Powder for Methanol Decomposition by Surface Chemical Treatments
Authors: Xu Ya , Demura Masahiko , Hirano Toshiyuki
Published: March 2013

The effect of acid and alkali leaching on catalytic activity of an atomized Ni3Al powder for methanol decomposition was investigated. It was found that a two-step process, an acid leaching followed by an alkali leaching, was most effective for improving the activity. The optimal conditions of acid and alkali leaching were examined. The effect of the acid and alkali leaching was attributed to the formation of fine Ni species and a porous surface structure.
Study on Preparation Process of Magnetic Abrasive Particles
Authors: Chen Yan , Li Yan Jun , Zhang Yao Ming , Zhang Xu
Published: March 2013

Abstract: With the industrial development and improvement of mechanical product quality, the demand of part surface quality and accuracy gets more and more high. As some parts of complex shape, can’t be machined by the traditional processing technology, therefore, the magnetic abrasive technique was proposed. The magnetic abrasive particles play an important role in the magnetic abrasive finishing, it use strong magnetic iron particles and abrasive particles mixed together (called magnetic abrasive). The prepared method of magnetic abrasive one of is sintering method, the aim is to change the internal structure of abrasive particles, make the abrasive particles is distributed on the surface of magnetic iron particles, get a kind of magnetic abrasive, which can be magnetized in a magnetic field and improve processing efficiency and surface quality in magnetic abrasive finishing. In this paper, sintering method is used to make iron particles, abrasive particles mixed with some binder, after suppression, drying, sintering, cooling, break up and sieving, analysis surface morphology and composition of the magnetic abrasive particles by scanning electron microscopy, discusses the effect of the abrasive particles size ratio, sintering time, sintering temperature for the finishing performs, the preparation process of the magnetic abrasive has been optimized, work out the standard of preparation of the magnetic abrasive process
Replication of Plastic Components with Silicon Moulding: Designed Experiments
Authors: Singh Rupinder , Sharma Vipul
Published: March 2013

In the present work, replication process for plastic components with silicon moulding (SM) has been investigated for statistically controlled rapid casting (RC) solution. Starting from the identification of component, prototype with three different types of plastic materials was prepared under different conditions of de-moulding time and mixing ratio. Relationship between dimensional accuracy in SM and other controllable parameters has been deduced by using Taguchi technique L9 orthogonal array. The study suggested the long-term performance level of the SM process after it has been brought under statistical control as RC solution for plastics. The provided data from the experimentation highlights the ability of the SM process to produce a product that will consistently meet the design requirements and the customer expectation. Keywords: Silicon moulding, dimensional accuracy, statistically controlled
Thermal and Photoluminescence Properties of Nd3+ Doped Tellurite Nanoglass
Authors: Mat Jan Nur Amanina , Sahar M.R. , Ghoshal Sib Krishna , Ariffin R. , Rohani M.S. , Hamzah K. , Ismail S.F.
Published: March 2013

Series of glasses based on (75-x)TeO2-15MgO-10Na2O-xNd2O3, where x=0, 1.0, 2.0 and 3.0, are synthesized by conventional melt-quenching technique. The nanoglass particles are derived from heat treatment of this glass near crystallisation temperature for 3 hours. The existence of nanocrystalline nature of this glass is confirmed by x-ray diffraction (XRD) technique followed by calculation using Scherrer equation. Meanwhile, the crystallization temperature, Tc determined using Differential thermal analysis (DTA). The fluorescence spectra of Nd3+ions exhibit emission transition of2P3/24I9/2,4G7/24I9/2,2H11/24I9/2, and4F9/24I9/2under 765 nm excitation wavelengths.
Elements of Dynamics Analysis of the Warship Launcher of Anti-Aircraft Short Range Homing Missiles
Authors: Dziopa Zbigniew
Published: March 2013

The paper presents a physical and mathematical model of a short range missile launcher based onboard a warship. The conducted numerical simulation allowed for developing an analysis of the anti-aircraft assembly dynamics. The selected responses of the system are demonstrated in the form of physical values characterizing the launcher motion.
Hyperbaric Swimming Simulator
Authors: Kłos Ryszard
Published: March 2013

This paper contains hyperbaric test facility equipped with swimming simulator description dedicated to diving apparatuses decompression research. This stand has been constructed within two scientific projects financed from research funds from the Polish Ministry of Sciences and Higher Education in 2009-2012 and it was realised in the Naval Academy of Gdynia.
Supporting the Empiric Research of Diesel Engines with Multi-Equation Models
Authors: Zadrąg Ryszard
Published: March 2013

Contemporary empirical researches on the object, which is combustion engine, are processed basing on the theory of experiment. Available software applications to analyze the experimental data commonly use the multiple regression models, which enables studying effects and interactions between input values of the model and single output variable. Using multi-equation models gives free hand at analyzing measurement results because it enables analysis of effects and interaction of many output variables. It also allows analysis of the measurement results during dynamic process. In this paper author presents advantages of using the multidimensional regression model on example of researches conducted on engine test stand.
Stochastic Nature of the Casting Solidification Displayed by Micro-Modelling and Cellular Automata Method
Authors: Burbelko Andriy A. , Gurgul Daniel , Kapturkiewicz Wojciech , Początek Jacek , Wróbel Marek
Published: March 2013

Some aspects of stochastic nature of the solidification processes are described. Firstly, the influence of the random grains nucleation on the cooling curves repeatability in the thin wall casting is presented. Secondly, the foundations of an average shape prediction for geometry of ele¬mentary diffusion field (concept of the Averaged Voronoi Polyhedron, AVP) are shown for the mi¬cro-modelling of the diffusion limited growth. Stochastic nature of the grains nucleation and growth is taken into account in the solidification modelling based on the Cellular Automaton technique (CA).
The Smooth Bootstrap Approach to the Distribution of a Shape in the Ferritic Stainless Steel AISI 434L Powders
Authors: Pietraszek Jacek , Gądek-Moszczak Aneta
Published: March 2013

The ferritic-austenitic stainless steel was obtained by sintering the mixture of ferritic stainless steel AISI 434L powders with different amount of additions: Mn, Ni and Si. The structure of obtained sintered samples was investigated by computer image analysis methods. In porous materials the character of the pore structure strongly effects on its mechanical properties. Accurate information about pores shape is important information for technological process and quality control of produced materials as well. The images of the porous microstructure were analyzed using ADCIS Aphelion analytical software. Analyzed pores have complex and irregular shapes and thus authors decided to appoint different shape factors to obtain its proper quantitative description. Data obtained from image analysis process were statistically analyzed. Authors used a special resampling approach known as smooth bootstrapping to smoothing cumulative empirical distributions. The results obtained during resampling procedure have been compared with raw data from verification set and guidelines for the application of the proposed approach have been formulated. The validity of the proposed approach was positively verified and it significantly improved quality of the results. The smoothing and imputing of data allow to avoid numerical artifacts that may arise during the classical statistical calculations on irregular data originated from image analysis obtained from sintered samples. Efficient, reliable and relatively fast method for accessing the distribution of any others quantitative parameters describing microstructure of the materials is very interesting proposal for wide spectrum of application.
Description of 3D Microstructure of the Composites with Polypropylene (PP) Matrix and Tuf Particles Fillers
Authors: Gądek-Moszczak Aneta , Żmudka Sabina
Published: March 2013

The main goal of the study was working out the method of qualitative and quantitative analysis of the microstructure on 3D images of the polypropylene composites with Tuf (type of rock consisting volcanic ash) particles. Three types of composite were analyzed: with 10, 15 and 25% of Tuf. The standard morphological parameters were indicated that describes size, shape, and distribution of Tuf particles in the matrix. The morphological characterization of examined microstructure was compared with mechanical properties. The optimal from the point of mechanical properties composition of this composite were proposed.
Comparison of Mechanical Properties of Mn-Cr-Mo Steels Sintered in Different Conditions
Authors: Sułowski Maciej , Matusiewicz Piotr
Published: March 2013

The present work discussed the development of statistical analysis as a reproducibility assistance method for evaluation of advanced Fe-3%Mn-(Cr)-(Mo)-C sintered steel for high performance structural parts. Factors contributing to the reliability and reproducibility of these structural steels include advanced metal matrix with consistent purity and concentration of chemical constituents, as well as mix homogeneity and processing uniformity. Matrix inhomogeneity was found to play an important role in these materials. In this paper the statistical dependence between properties and processing variables of PM Mn-Cr-Mo steels is presented. The investigations of sintered steels were based on commercial powders: pre-alloyed Höganäs iron powders Astaloy CrM and Astaloy CrL and graphite C-UF. As a manganese donor low-carbon ferromanganese powder was used. Sintering was carried out in different atmospheres at 1120°C and 1250°C. After sintering, investigated steels were subsequently tempered at 200°C for 60 min in air. The results of statistical analysis show, there is the relationship between mechanical properties versus processing parameters.
The Influence of e-Beam Irradiation on the Morphology and Functional Properties of UHMWPE
Authors: Maszybrocka Joanna , Barylski Adrian , Cybo Jerzy , Czaja Piotr
Published: March 2013

The paper presents an analysis of the effectiveness of radiation modification of GUR 1050 and GUR 1020 polymers intended for endoprosthesis bearing components. It has been demonstrated through extraction and expansion that the crosslinking density increases as the applied dose of electron irradiation and the molecular weight of polyethylene grow. The recorded changes were accompanied by an increase in the degree of crystallinity, which was more significant in the case of the more heavy GUR 1050 (compared to GUR 1020). The morphological changes are supported by the results of micromechanical, sclerometric and tribological examinations. Tribological examinations were documented with SEM images of the surface of specimens subjected to oscillatory friction (roll-block tester). Series of crosswise valleys and projections, arranged along the friction direction, were found on the friction surface. The smoothening of the surface and a lack of lamella fragments on the base specimens which were not subjected to e-beam irradiation are observed along with a reduction of wear due to the increasing dose of irradiation.
Quantitative Characterization of Shrinkage and Gas Pores in Turbine Blades Made of MAR M247 and IN 713C Superalloys
Authors: Roskosz Stanisław
Published: March 2013

The subject matter of the paper is the quantitative evaluation of gaseous and shrinkage porosity in construction elements of a low-pressure aircraft engine turbine using quantitative metallography methods. The research material comprised blades and blade segments with a polycrystalline structure made of IN 713C and MAR M247 superalloys. One of the major problems that occur in the precision castings is their porosity: gaseous, which is the result of emission of dissolved gases from the superalloy during solidification, and shrinkage, being the result of shrinkage of the superalloy and of insufficient feeding of the interdendritic space. The developed practical procedure of selective measurement of gaseous and shrinkage porosity enabling the examination of precision castings made of high-temperature creep resisting nickel superalloys is presented.
Mobile Sensor Motion Planning for Identification of a Contamination Source Using Iterative Dynamic Programming
Authors: Ziemniak Paweł
Published: March 2013

A systematic iterative dynamic programming procedure is proposed for on-line motion planning of mobile sensor network nodes in a specified spatial domain in such a way as to maximize the identification accuracy of an unknown contamination source. The design criterion is a general scalar measure defined on the Fisher information matrix associated with the estimated coordinates of the contamination source. The approach converts the problem to an optimal control one in which the control forces of the sensors are optimized using iterative dynamic programming.
Mathematical Model of the Servo Drive with Friction Wheals. Simulations and Real Object Examination Results
Authors: Fracczak Lukasz
Published: March 2013

In this paper the servo drive with friction wheels is presented. The servo drive is designed to move the automatic laparoscope tool or laparoscope camera (thereinafter laparoscope sleeve or sleeve) in two Degrees of Freedom (DOF). The description of the drive mechanism, operating principle and mathematical model of this drive is presented. Based on this model, the Control System (CS) has been created, and used to the construction of a simulation model. The simulation illustrates the proper functionality of the mathematical model of the servo drive with the described CS. This paper also presents the servo drive test stand and the most important examination results from the point of view of using them in the cardiac surgery Robin Heart robot.
Preliminary UAV Autopilot Integration and In-Flight Testing
Authors: Ambroziak Leszek , Gosiewski Zdzisław
Published: March 2013

The paper presents integration process of commercial autopilot. The autopilot was integrated with a fixed wing airframe. The main aim of this work was an experimental study of the autopilot integrated with a micro aircraft. A few manual and autonomous mode flights were performed. During the field trials the autopilot PID parameters were tuned and, as a result, the process of PID gains selection was described. Selected PID gains were presented. Certain telemetry parameters such as longitudinal and lateral position of aircraft, orientation angles, and angular velocities were logged during flight and analyzed. Maximum and minimum airspeeds at a desired altitude were measured and presented. Moreover, Received Signal Strange Indicator between ground station and UAV equipped with special antenna was measured and logged for radio communication quality and range checking. Presented analysis of the autopilots work and obtained results were used to assess the applicability of this hardware to next formation flight operations.
Testing Some Alpha-Models of Turbulence on Wing Profiles
Authors: Moreno Miguel A. , González Begoña , Enríquez Vicente , Déniz Fabián A. , Aguasca Ricardo , Winter Gabriel
Published: March 2013

In this paper some numerical simulations of the Navier-Stokes Equations (NSE) to test the novel NS-α and NS-ω turbulence models [1, , which conserve energy, enstrophy, and helicity, are presented. These algorithms verify more conservation properties than other implementations of the NSE, however their rotational form [ makes the scaling study of the coupling between the velocity and pressure errors with respect to the Reynolds number, a very interesting research line. Nowadays we are designing a wing profile in the context of Unmanned Aerial Vehicle (UAV) on incompressible flow conditions [. First a genetic algorithm (GA) is used to obtain the optimized design geometry and then the NS-α and NS-ω turbulence models are run to study its performance for different attack angles. The GA objective function evaluates the general potential theory of each wing section considered, because that requires less computational cost than the alternative of solving the NSE, and a wing design method proposed in [ is applied. Thus the optimized design geometry was found by evaluating the potential flow of all candidate solutions generated from the selection, crossover and mutation operators in each GA iteration. It takes the order of hundreds of simulations per iteration to evaluate all candidate solutions. Summarizing, two practical applications for a UAV are presented: the optimized design of an airfoil for environmental purposes, named CEANI airfoil, and the application of relevant turbulence models as NS-α and NS-ω in order to evaluate with accuracy the lift, drag and maximum angle of attack.
Investigation of Multifunctional Actuators on an Air-Cushion
Authors: Vaitasius Kęstutis , Pauliukaitis Darius , Kibirkštis Edmundas
Published: March 2013

This paper analyses the area in which synchronic operation of several pneumatic actuators connected by a rigid link exists. The minimum values of the supplied compressed air have been determined under which self-exciting vibrations appear in the system of several actuators. The influence of the transducers geometrical parameters on the variation law of motion of the system working organ has been investigated. It has determined that character of dependencies of peak-to-peak and frequency upon pressure of system is similar to character of dependencies separate transducer and that having picked up geometrical and dynamic parameters actuators it is possible to receive difficult (biharmonic) movement of system. This property can be applied in vibrostands meant for material or equipment trials and their vibrational processing.
Magnetic Field and Circuit Parameters in an Electromagnetic Generator Supporting a Rotary MR Damper
Authors: Sapiński Bogdan
Published: March 2013

This paper summarises the results of numerical calculations of magnetic field and circuit parameters in an electromagnetic generator supplying a rotary MR damper. The design and operating principles of the generator are outlined. The distribution of the magnetic flux density vector is obtained, other parameters include its modulus, the magnetic flux from permanent magnets and time patterns of induced voltage and current in the control coil of the damper, power and energy of magnetic field in this coil at different rotational speeds of the induction with respect to the armature.
Mathematical Analysis and Investigation Results of the Bearingless Electric Motor with Permanent Magnets
Authors: Henzel Maciej
Published: March 2013

The paper deals with analysis of bearingless electric motor with surface-mounted permanent magnets. This kind of electric motor eliminate disadvantages of conventional motors, e.g. overall efficiency, friction forces, heat abstraction. In paper are shown mathematical analysis of bearingless motor and experimental investigation results of them. There are shown results of analysis of magnetic flux density distribution in bearingless motor by finite element method, too. This kind of motor was elaborated and investigated in Military University of Technology.