bluuebunny/crossref_metadata_2025 huggingface dataset:
Ion Track Matrices: Porous Structure, Deposition of Metals and Emission Properties of Obtained Replicas
Authors: Zagorskiy D. , Bedin S. , Oleinikov V. , Korotkov V. , Kudryavtsev V. , Mchedlishvili B.
Published: July 2013

This paper is devoted to production of metallic micro-and nanowires (Cu, Co, Ni and Fe) using commercial track membranes. Specially prepared matrices were also fabricated and used for this purpose. The process of electrodeposition of these metals into the nanosized pores was investigated and found to be non-linear for small pores. The obtained ensembles of nanowires could be used as the effective templates for emission of molecules in mass-spectrometry. Mass-spectra of test peptide (gramicidin deposited on substrate - ensemble of copper nanowires) was obtained and investigated in different conditions.
Effect of Swift Heavy Ion Irradiation on Structural and Magnetic Properties of Strontium Hexaferrites
Authors: Panchal Nital R. , Jotania Rajshree B.
Published: July 2013

Swift heavy ion irradiation of material is a unique tool to modify the properties of the material and it provides an alternative to photons for introducing electronic excitations into the material. In the present investigation, the changes in structural, morphological and magnetic properties of SrFe12O19 ferrite (prepared using co-precipitation and SHS routes), induced by 200 MeV Ag+16 ion irradiation have been studied. In order to study the effect of the electronic stopping power (dE/dX) e on these properties the energy of the projectile was so chosen that it could easily pass through the samples. Structural properties of these ferrites have been studied and compared with the properties after Swift Heavy Ion (SHI) irradiation of 200 MeV Ag16+ at different fluences. Samples were characterized using different experimental techniques, like Fourier Transform Infra-red (FT-IR), X-ray Diffraction (XRD), Scanning Electrom Microscope (SEM), Vibrating Sample Magnetometer (VSM) and LCR meter. FTIR spectra for pristine as well as the irradiated samples were recorded for wave number ranges from 4000-400 cm-1 using the KBr pellet method. FTIR measurement of the bonds' vibration modes in all samples were carried out to determine the change in MO bonding due to irradiation. The MO absorption band is observed in all samples. The intensity of absorption bands increased in irradiated samples, which confirms the formation of strong ferric oxide band. Crystallinity of pristine and irradiated samples was investigated by XRD technique. All XRD peaks were indexed using POWDER X software. XRD result confirms the formation of mono phase. It is observed from XRD analysis that after the irradiation, the intensity of all the peaks and FWHM were increased. There is no significant change in peak position but the intensity is decreased and FWHM is increased continuously with ion fluence. XRD patterns confirm that the ferrite structure is retained even after irradiation. Surface morphology of pristine and irradiated samples was studied using a scanning electron microscopy. It is observed from SEM images that the particle size decreases after irradiation and particles become more homogeneous. Dielectric and magnetic measurements were also carried out.
Effect of N2 Ion Bombardment on Optical and Mechanical Properties of Ultra-High Molecular Weight Polyethylene (UHMWPE)
Authors: Abdul-Kader A.M. , El-Gendy Y.A. , Al-Rashdi Awad A. , Salem A.M.
Published: July 2013

The effect of ion beam bombardment on the optical and mechanical properties of ultra-high molecular weight polyethylene (UHMWPE) was investigated. UHMWPE polymer samples were bombarded with 150 keV N2ions under vacuum at room temperature to high fluences ranging from 1x1016to 2x1017ions cm-2. The untreated as well as treated samples were investigated by ultraviolet-visible (UV-Vis) spectrophotometer and Vickers micro-hardness techniques. The direct and indirect optical band gap decreased from 2.9 and 1.65 eV for pristine sample to 1.7 and 1 eV for those bombarded with N2ion beam at the highest fluence, respectively. With increasing ion fluence, an increase in the number of carbon atoms per conjugation length, N and number of carbon atoms per cluster, M in a formed cluster were observed. A significant improvement in surface hardness was obtained by increasing the ion fluence.
Production of Metallic Iron from Iron Oxide (Fe2O3) Using End-of-Life Rubber Tyre and its Blends with Metallurgical Coke as Reductants
Authors: Dankwah James Ransford , Koshy Pramod
Published: July 2013

The production of metallic iron from iron oxide using end-of-life tyres (RT) and its blends with metallurgical coke as reductants has been investigated through experiments conducted in a laboratory scale horizontal tube furnace. Composite pellets of iron oxide (96.89 % Fe2O3) with RT, coke and coke/RT blends (in four different proportions) were rapidly heated at 1500 °C under high purity argon gas and the off gas was continuously analysed for CO and CO2 using an online infrared gas analyser (IR). The extent of reduction after ten minutes, level of carburisation of the reduced metal and the total amount of CO2 emissions were determined for each carbonaceous reductant. The results indicate that metallic iron can be effectively produced from Fe2O3 using RT and its blends with coke as reductant. The extent of reduction and level of carburisation are significantly improved when coke is blended with RT. Blending of coke with RT resulted in significant decrease in CO2 emissions.
Sol-Gel Mullite-SiC Oxidation Protective Coating for Carbon-Carbon Composites
Authors: Gbologah Lemuel , Kwawukume P.S. , Momade Francis W.Y.
Published: July 2013

Carbon-Carbon composite (C/C) substrate materials are prone to severe oxidation and volatilization problems. To address these issues mullite/SiC coatings were deposited on C/C composite. The coatings were applied by a two-step approach; pack cementation and silica sol based slurry-coating processes. The pack mixture composition for SiC coating comprised; 15-50 wt. % Si (75 μm), 0-25 wt. % B (38.2 μm), 0.01-3 wt. % SiO2 (38 μm) and 40-85 wt. % SiC green (20 μm). Laboratory synthesized mullite via sol-gel (SG) process of different Al2O3/SiO2 ratios (containing approx. 84-72wt. % Al2O3) based on stoichiometric calculation were used; these were admixed with silica sol to form a slurry. The pack mixture and the silica sol based slurry coatings were sintered at temperatures of 1800oC and 550°C respectively. The microstructure and isothermal oxidation behavior of the mullite/SiC coatings and C/C substrates during isothermal oxidation cycle at 1500oC were investigated using XRD and SEM mounted with EDS. Results indicate that optimized oxidation protection for mullite-SiC coating was achieved with higher Al2O3 content. The weight loss rate of sol-gel mullite with bulk composition 84 wt. % Al2O3 (SG84) was 0.09 gcm-2h-1 as compared to bulk composition 72 wt. % Al2O3 (SG72) which had a weight loss rate of 0.20gcm-2h-1. The oxidation protection for the synthesized sol-gel mullite/SiC coatings offered effective protection as evidenced in the cycle hour exposure time with limited degradation, chemical compatibility between the coating/substrate interface was good and the phases were quite stable after isothermal oxidation cycle.
Effect of Chain Morphology and Carbon-Nanotube Additives on the Glass Transition Temperature of Polyethylene
Authors: Herasati S. , Ruan H.H. , Zhang Liang Chi
Published: July 2013

Glass transition temperature Tg is the most important parameter affecting the mechanical properties of amorphous and semi-crystalline polymers. However, the atomistic origin of glass transition is not yet well understood. Using Polyethylene (PE) as an example, this paper investigates the glass transition temperature Tg of PE with the aid of molecular dynamics (MD) simulation. The effects of PE chain branches, crystallinity and carbon-nanotube (CNT) additives on the glass transition temperature are analyzed. The MD simulations render a good agreement with the relevant experimental data of semi-crystalline PE and show the significant effects of crystallinity and addition of CNTs on Tg.
Fabrication of High-Verticality Grating Nanostructures Using Twice-Deposited Etching Mask Layers
Authors: Liu Z.H. , Pan Cheng Teng , Chao C.H. , Wang W.C. , Liu C.Y.
Published: July 2013

To study the influence of twice-deposited mask layers on the verticality of side wall and the aspect ratios of silicon-based nanostructures, the performance of focused ion beam (FIB) and CF4-based inductive coupled plasma reactive ion etching (ICP-RIE) processes was realized. The first etching mask of chromium (Cr) was deposited by radiofrequency (RF) magnetron sputtering as the conductive and etching barrier layers. Next, the Cr layer was directly patterned by a dual-beam FIB system to form nanograting patterns. Thereafter, a secondary mask layer of oxide (SiO2) with a thickness of 50 nm was deposited by sputtering. In order to study the influence of various deep etching parameters on verticality and aspect ratios, we examined argon flow rates, coil powers, platen powers, and chamber pressures. The SiO2 barrier layer on the side wall could be retained to maintain a high verticality contour and reduce the line-width shrinking ratio to surmount over etching during the use of fluorine-based gas. The residual Cr and SiO2 layers were dissolved and removed using a wet etching process consisting of a Cr-etching solution (CR-7). Measurements show that the verticality and aspect ratios of the grating nanostructures were 92.1° and 5.63, respectively.
Characterization of Fabricated Feedstock Using Nano Powders and a Water-Soluble Binder in Micro Metal Injection Molding
Authors: Javad Rajabi , Muhamad Norhamidi , Sulong Abu Bakar , Hasyimah Aziz , Fayyaz Abdolali , Zakaria Hafizawati
Published: July 2013

Micro metal injection molding has become the promising method in powder metallurgy research in order to fabricate small-scale intricate parts in an influential process and competitive cost of mass production. Stainless steel 316 L powders with powder size of 150 nm and 5 μm were mixed with a binder with a water soluble component which consisted of a major fraction of water soluble Polyethylene Glycol (PEG), a minor fraction of polymethyl-methacrylate (PMMA) and some stearic acid has been used as a surfactant. This work aims to investigate the rheological properties of a feedstock which are efficiently characterised by capillary Rheometry to measure apparent viscosities at different temperatures and shear rates. Results obtained by the varying feedstock characteristics, when viscosity decreases by increasing of shear rate at certain temperature feedstock should have a pseudoplastic behaviour. Melt viscosity of the feedstock was decreased by adding nanoscale powders. The reduced (n) values at high temperature with addition of nanoparticles indicated a possible increase in the shear-thinning behavior.
Preliminary Study on the Fabrication Mechanism of Nanofibers in the Melt Splitting Process
Authors: Wu Li Li , Cheng Yuan Ling , Chen Ting
Published: July 2013

Melt splitting is a new technique for the mass production of nanofibers. The polymer melt split radially into several hundred very fine filaments in a specially designed nozzle. The prediction model for filament diameter after splitting in the melt splitting process is established based on the surface wave method. The predicted filament diameter compares favorably with the experimental data. Effects of the air pressure and polymer flow rate on the filament diameter are studied. It is found that larger air pressure and smaller polymer flow rate can all produce finer filaments. The results provide a good foundation for the optimization of the melt splitting technique.
Effect of Ultrasonic Vibration on Structure and Performance of Electrospun PAN Fibrous Membrane
Authors: Qiang Jing , Wan Yu Qin , Yang Li Na , Cao Qin Qin
Published: July 2013

The major topic covered in this paper is fabrication and performance study of polyacrylonitrile (PAN) ultrafine fibers from high-concentration solutions via a vibration-electrospinning technique. The influences of ultrasonic vibration on the solution properties of high viscous PAN solution as well as surface morphology and mechanical performance of PAN fibrous mats were investigated. The results indicated that: (1) the effect of ultrasonic vibration on the mechanical properties was significant; (2) the vibrorheological effects of ultrasonic vibration appeared not only in dramatic reduction of polymer viscosity, but also in improvement of the electrospinnability of polymer solutions; (3) fibers with smaller diameter, better uniformity and fewer surface defects were prepared with the application of vibration; and (4) the tensile strength of membranes was substantially enhanced at optimized vibration parameters comparing that without vibration treatment.
Microstructure and Electrochemical Properties of Lithium Titanate Particles Prepared by Solid State Reaction of Li and Spherical TiO2 Powders
Authors: Yamada Motofumi , Kawaguchi Hiroshi , Kodera Takayuki , Ogihara Takashi
Published: July 2013

Li4Ti5O12 powders were synthesized via the solid state reaction of Li2CO3 and spherical composite powders of carbon and TiO2 (denoted by C/TiO2) with different microstructures. These C/TiO2 powders were synthesized by spray pyrolysis using various organic acid aqueous solutions. The particle characteristics of the resulting carbon composite Li4Ti5O12 (denoted by C/Li4Ti5O12) powders were determined using SEM, XRD, and DTA-TG. DTA-TG showed that the carbon content of all Li4Ti5O12 powders. was around 3 wt%. XRD revealed that the spinel structure (Fd3m) was obtained by heating at 750 °C under N2 atmosphere. The initial rechargeable capacity of the C/Li4Ti5O12 powders formed using citric acid was approximately 170 mAh/g at 1 C. The rechargeable capacity of the C/Li4Ti5O12 powders decreased with an increase in the rechargeable rate. The anodes maintained over 90% of their initial discharge capacity after 200 cycles at 1 C. The C/Li4Ti5O12 powders also demonstrated high cycle stability at 50 °C. It was found that rechargeable capacity was influenced by the particles microstructure, but cycle stability did not depend on the microstructure.
Effect of Heat Treatment on Charge-Discharge Property of Fluoride Cathode Materials for Li Ion Secondary Batteries
Authors: Tomita Yasumasa , Kato Jinta , Kohno Yoshiumi , Maeda Yasuhisa , Kobayashi Kenkichiro
Published: July 2013

ron fluoride (III) anhydrate fine particle was prepared by drying in vacuum from FeF3·3H2O, a mechanical milling process and a calcination at 473 773 K. Particle size of FeF3·3H2O was ca. 3 5 μm and that of FeF3 anhydrate was 100 500 nm after drying and milling. FeF3 sample only after drying and milling was hygroscopic and became FeF3·3H2O under atmosphere. FeF3 became stable under atmosphere after oxidation at 673 K for more than 20 minutes. It was found that Fe2O3 was produced by calcination and covered the surface of FeF3 particles. In Charge-discharge measurements, the discharge capacity of these FeF3 samples was 150 - 200 mAh/g at a discharge rate of 0.1 C. The oxidation could improve the discharge properties of FeF3 cathode.
Microscopic Conduction Behavior Analysis on ZrO2-Based Ion Conductors by Wideband Conductivity Measurement
Authors: Teranishi Takashi , Shimizu Kosuke , Hayashi Hidetaka , Kishimoto Akira
Published: July 2013

All contributions to the total conductivity, electrolyteelectrode interfaces, grain boundaries, ion-hopping, and optical phonons, were determined on the 8 mol% yttria-stabilized zirconia (8YSZ) and 8 mol% ytterbia-stabilized zirconia (8YbSZ) ceramics using the wideband conductivity spectroscopy. Complex conductivity spectra from 101Hz to 1014Hz were successfully obtained. The higher total conductivity of the 8YbSZ ceramics compared to the 8YSZ in wideband frequencies was mainly attributed to difference in the DC conductivity due to universal dielectric response (UDR),σdc;σdc(8YbSZ)>σdc(8YSZ). Other parameters in the UDR and the optical phonon parameters did not greatly influence on the difference in their intrinsic conductivities.
Proton Storage Properties of Manganese Oxides with Tunnel Structures
Authors: Dohkoh Tatsuki , Suzuki Shinya , Miyayama Masaru
Published: July 2013

The electrochemical capacitors (ECs) have attracted a great attention as a rechargeable strage device with a high power density and high safety. An increase in specific capacity is demanded to use ECs in various applications. MnO2 are expected as electrodes of ECs because of their large oxidation state change (Mn4+ Mn2+), low cost and environmental compatibility. When all manganese ions in the MnO2 are completely reduced to Mn2+ from Mn4+ over a potential window of 1.1 V, the theoretical capacity is estimated to about 2000 Fg-1. However, the reported capacity of MnO2 electrodes are 100250 Fg-1 [1-2] for powders and around 700 Fg-1 [3] for thin films. Tunnel structured MnO2 are expected to show high capacities by utilizing high ionic mobility in the tunnel and high surface area of tunnel walls. Fig. 1 shows crystal structures of (a) Pyrolusite (Tunnel size: 1×1), (b) Hollandite (Tunnel size: 2×2) and (c) OMS-5 (Tunnel size: 2×4) and (d) MnO6 unit. In the present study, the relationship between the tunnel size and the specific capacity was investigated for those tunnel structured MnO2. In addition, Hollandite /carbon composites were synthesized to improve the electrode properties of Hollandite.
Ferroelectric Properties Improvement of Mn-Doped 0.7BiFeO3-0.3BaTiO3 Thin Films Fabricated by Chemical Solution Deposition
Authors: Ito Yuya , Moriya Makoto , Sakamoto Wataru , Yogo Toshinobu
Published: July 2013

Ferroelectric 0.7BiFeO3-0.3BaTiO3 and 0.7BiFe0.95Mn0.05O3-0.3BaTiO3 thin films were prepared by the chemical solution deposition. Perovskite single-phase thin films with homogeneous surface morphology were successfully fabricated at 700°C on Pt/TiOx/SiO2/Si substrates. Although typical polarization (P)-electric field (E) hysteresis loops were observed for 0.7BiFeO3-0.3BaTiO3 thin films, their insulation resistance was relatively low at room temperature. Mn doping for Fe site of the 0.7BiFeO3-0.3BaTiO3 was very effective in improving leakage current properties. In 0.7BiFe0.95Mn0.05O3-0.3BaTiO3 thin films, the abrupt increase in leakage current was suppressed even at high electric fields, leading to the well-shaped P-E hysteresis loops at ambient temperatures. Remanent polarization and coercive field of the 0.7Bi (Fe0.95Mn0.05)O3-0.3Bi0.5Na0.5TiO3 films at room temperature were approximately 26 μC/cm2 and 130 kV/cm, respectively.
Evaluation of TiO2 Films Fabricated by Aerosol Deposition
Authors: Yuuki Kazuo , Uemichi Yuta , Sato Yuuki , Yoshikado Shinzo
Published: July 2013

Films of titanium dioxide (TiO2) were deposited by aerosol deposition at room temperature. Anatase TiO2 powders were used. The crystal structure of these films was a mixture of the anatase and brookite TiO2 phases, while the rutile TiO2 phase was observed at high carrier gas flow rates. The TiO2 film thickness increased in proportion with the scan time and the carrier gas flow rate. Film thickness was constant at constant total deposition times. Flake-like and mesh-like surface morphologies were observed on the films. The direct-current resistivity was estimated from the dielectric constant and the loss tangent; it was found to be much smaller than that of bulk TiO2. We speculate that this low resistivity is due to reduction of TiO2 particles during room-temperature impact consolidation in a N2 atmosphere.
Relation between Electro-Optic Effect and Dielectric Permittivity of Ba0.5Sr0.5TiO3 Thin Films
Authors: Takeda Kotaro , Hoshina Takuya , Takeda Hiroaki , Tsurumi Takaaki
Published: July 2013

The relation between the dielectric tunability and the electro-optic (EO) effect of barium strontium titanate (Ba0.5Sr0.5TiO3) thin film was discussed. The tunability of dielectric permittivity calculated from the complex admittance with planer electrodes reached to 53.1%, and the tunability of birefringence by EO effect was 0.6%. The birefringence change from EO effect was much lower than the tunability of dielectric permittivity. The materials with high tunability do not always exhibit high EO effect. This is concluded to arise due to the ionic mass in the EO materials.
Microstructure Control of Potassium Niobate Porous Ceramics and their Sensor Properties
Authors: Maeda Kazuki , Yamashita Kenta , Fujii Ichiro , Nakashima Kouichi , Suzuki Tohru , Kuroiwa Yoshihiro , Wada Satoshi
Published: July 2013

Porous potassium niobate (KNbO3, KN) system ceramics were prepared by spark plasma sintering (SPS) method using carbon black (CB, 5 μm). First, the powders of raw materials were mixed in ethanol by ball milling, and then calcined. Obtained KN powders with CB were sintered by SPS in argon atmosphere. Their piezoelectric properties were measured and a relationship between porosity, pore size, and sensor properties was studied. It was found that d33 increased as pore size decreased. Thus, pore size was important for the improvement of value of g33/ρ.
Effect of a Boron Additive on the Microstructure and Dielectric Properties of BaTiO3 Thin Films Formed by Nanocrystal Deposition
Authors: Takezawa Yoko , Ryu Minoru , Iwazaki Yoshiki , Suzuki Toshimasa , Mizuno Youichi , Imai Hiroaki
Published: July 2013

Highly crystallized BaTiO3 thin films were fabricated by a nanocrystal sintering process. Boron alkoxide was introduced into a slurry of Mn-doped BaTiO3 nanocrystals with particle sizes of 5-7 nm. The deposited nanocrystal film on a (111)-oriented Pt/TiO2/Al2O3 substrate was sintered at a low temperature of 800 °C and the obtained film had highly densified and oriented microstructures. We found that the boron additive enhanced the grain growth of nanoparticles and as a result the dielectric constant of the thin film increased to 1100 at 10 kHz, which is much higher than that of undoped BaTiO3 thin films.
Fabrication and Characterization of Perovskite Nanocube Ordering Structures via Capillary-Force-Assisted Self-Assembly Process
Authors: Mimura Kenichi , Dang Feng , Kato Kazumi , Imai Hiroaki , Wada Satoshi , Haneda Hajime , Kuwabara Makoto
Published: July 2013

Barium titanate (BT) and strontium titanate (ST) nanocubes which have been synthesized by hydrothermal method with surfactants were assembled in order directly on the substrates by using capillary-force-assisted self-assembly method. The ordered structures, crystallinity and orientation of the nanocubes were evaluated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning probe microscopy (SPM) and X-ray diffraction (XRD). The piezoresponse properties of the nanocubes ordering structures characterized by Piezoresponse Force Microscopy (PFM) seemed to depend on the constituents and their interface.
Preparation of Strontium Titanate-Coated Barium Titanate Accumulation Ceramics by Solvothermal Synthesis and their Dielectric Property
Authors: Iwatsuki Shogo , Goto Takayuki , Kera Masatoshi , Nakashima Kouichi , Fujii Ichiro , Ryu Minoru , Suzuki Toshimasa , Wada Satoshi
Published: July 2013

The strontium titanate (SrTiO3, ST) -coated barium titanate (BaTiO3, BT) complex nanoparticles was prepared. Using this condition, ST-coated BT (ST/BT) and ST-coated ST (ST/ST) nanocube accumulation ceramics were successfully prepared with epitaxial interface between ST and BT. Dielectric properties were measured for the both accumulation ceramics, but there was no difference of the dielectric properties between both ceramics, and the origin of the result was discussed.
Evaluation of Green Cement Manufacturing Seeking Joint Treatment for Urban Refuse
Authors: Tang Yue Qin
Published: July 2013

Sanitary landfill, Burning, Compost are the main method to dispose gabage in China.If urben refuse is put into the cement kiln, processing it, producing cement, it will benefit all. This mature method has no influence on neither the cement production nor the quality of cement products,however the indexes of all emissions in the manufacturing meet the national standards. Statistics show the heat generated by every ton of waste is equal to that of 183kg standard coals; the cinders are mixed in cement during the treatment process, thus 107kilograms substitute raw materials can be generated by every ton of waste, and 6 to 7 percent are added. Moreever, it reduces carbon dioxide emission 8000 tons for every 10,000 tons waste. This paper concludes: the utilization of cement kiln to incinerate domestic waste has obvious advantages in environmental protection and total investment does not cost much. The municipal engineering construction has the priority to use the products from domestic treatment cement factories, and domestic waste incineration cement factories should be under self-management. Also supportive policies as well as the readjustment of waste treatment management and interest pattern can promote the development of treating urban domestic waste by cement production.
Experiment Study on Micro-Cylindrical Electrode Fabrication in Electrochemical Machining
Authors: Wang Yi Gang , Li Zhi Yong , Liu Hong Li , Duan Zhi Peng
Published: July 2013

Aiming at the key techniques in ECM, the ECM system has been developed. The micro-tool-electrode and workpiece have been machined on the machine tool. Base on the experiment analysis of the effect of voltage, immersion depth, power characteristics on its forming laws in the micro-tool-electrode machining, the ECM has been realized in low concentration alkaline electrolyte. A micro-tool-electrode with the length of 1200 um, the diameter of 16 um, and aspect ratio of 75:1 has been machined by the developed machine tool.
Research on Balancing of a Multi-Link High-Speed Precision Press
Authors: Lu Xin Jian , Zhu Si Hong , Kang Lei , Xiao Mao Hua
Published: July 2013

Balancing mechanism for a multi-link high-speed precision press has been proposed and kinetic equations for the press with balancing mechanism have been derived also. The corresponding computer program has been developed on the basis of Matlab software environment. Take the press developed in the research as an example to calculate for studying balancing effect of this mechanism. Calculation results show that the balancing mechanism can significantly reduce vertical inertial force acted on the bed on the one hand; on the other hand the horizontal inertial forces of some parts and torque need will be increased. Results of the research mentioned above can be used for development of the multi-link high-speed precision press.
Experimental Study on Performance of CBN-Coated, CBN-Uncoated and PCD Tools in Turning Al 2124 SiC (45%wt) PMMC
Authors: Njuguna Muguthu Joseph , Gao D.
Published: July 2013

The machining of PMMCs is very difficult due to the highly abrasive and intermittent nature of the reinforcement. It is therefore necessary to choose tool material wisely. The focus of this paper was to assess performance of CBN-uncoated, CBN-coated and PCD tools with respect to tool wear, wear mechanism and cutting force while turning of Al 2124 SiC (45%wt) Particulate Metal Matrix Composite. Experimental results reveal that abrasion and chipping presented the most prevalent mode of wear among the CBN-uncoated, CBN-coated and PCD tools. Flank and crater wear were observed in all tools with flank wear being more prevalent in CBN-coated and CBN-uncoated tools. Wear among PCD tool was low as compared to CBN-uncoated CBN-coated. PCD tool is more suitable for cutting Al 2124 SiC(45%wt) PMMC.
A Simple Method for Identification of the Alloy’s Non-Crystalline Structure
Authors: Xiao Hua Xing
Published: July 2013

In the thermomagnetism analysis, the ferromagnetic amorphous alloy near or after the Curie temperature within a certain scope was in the paramagnetic condition with low magnetization. When the heating temperature achieved the crystallization temperature of the amorphous alloy, the magnetization increased significantly due to the crystallization of the alloy. As the obvious crystallization of the amorphous alloy, the crystallization phase with a high Curie temperature (Tc) formed and the ferromagnetism of the alloy would not be fully transferred to paramagnetism. The magnetization of the alloy would maintain at a stable high level before it had been fully crystallized. Therefore, the structure of the ferromagnetic amorphous alloy can be identified accurately by the obvious difference between the thermomagnetism curves before and after crystallization.
Finite Element Analysis of Ultrasonic Vibration Assisted Turning of Ferrous Metals
Authors: Zou Lai , Zhou Ming
Published: July 2013

Ultrasonic vibration assisted turning has significant improvements in processing of intractable materials compared to conventional turning. This paper presents a theoretical investigation of tool wear in single point diamond turning of ferrous metals based on numerical simulation. Finite element modeling and simulation of ultrasonic vibration turning process were performed, aimed at optimizing a series of technological parameters in the process of machining, reducing tool wear and improving surface quality as much as possible. The results revealed that the cutting speed and depth of cut are two crucial factors for tool wear, unlike the other parameters of vibration frequency, amplitude and flank angle. Moreover, this technological measure has observably decreased the cutting force and cutting temperature, so as to obtain superior surface finish.
Risk Warning of High-Tech Enterprise Independent Innovation Based on Chaotic Neural Network
Authors: Wu Zhi Yong , Chen Hong Mei , Qi Xiu Hui
Published: July 2013

Risk warning evaluation index system of independent innovation is established according to the process of innovation activities of high-tech enterprise, Chaotic Analysis Method is introduced into the BP(Back Propagation)Neural Network Model to research the early risk warning of high-tech enterprises independent innovation, the empirical results show that the integration of early warning model is feasible and effective, and significantly improve the convergence speed of network training, to some extent, avoid getting into local minimum.
Bone Scaffold Forming Filament Width Prediction of LDM Based on the Improved BP Neural Network
Authors: Liu Yuan Yuan , Han Zhen Zhong , Fang Shu Hui , Liu Da Li , Liu Ying , Hu Qing Xi
Published: July 2013

LDM process is used for preparing three-dimensional scaffolds for tissue engineering rapid prototyping technologies. Because of its forming process is complex, which influenced by a variety of factors, so the processing environment is not stable, the forming of scaffold pore size can not be guaranteed, therefore the forming precision is poor. However, the scaffold pore size accuracy is mainly decided by the wire filament width. Neural network theory and development provides a powerful tool for the study of nonlinear systems. This article analyzed the influence factors for forming bone scaffold filament width of LDM process, based on improved BP neural network, using MATLAB software programming, then predicted the filament width. The results show that model prediction error was less than 8%, it has high forecasting precision, and it can be used to guide the LDM process parameter selection and forming precision of prediction.
Research on Response of Copper to Micro Laser Shock Peening under 2-D Pressure Model
Authors: Fan Yu Jie , Yin Kai Ting , Zhu Yong Mei
Published: July 2013

2-D pressure model in axial and radial direction was proposed to simulate response of copper subjected to micro laser shock peening (μLSP) according to the size effect in the propagation of shock wave induced by laser in microscale. Simulations under 1-D and 2-D pressure model were conducted respectively in order to explore the effect of pressure in radial direction. The results show that distribution of residual stress and plastic deformation in depth and width are obviously different, and response of copper under 2-D pressure model are more close to the experimental results. The pressure effect in radial direction in the propagation of shock wave shouldnt be ignored, and 2-D shock wave pressure model plays an important role in accurate simulation of μLSP.
Modeling and Analyzing the Temperature Field in EACVD Integration System
Authors: Liu Li Hong
Published: July 2013

Numerical simulations were used to investigate the influence of various hot filaments and other deposition parameters on substrate temperature field which affects significantly the growth and quality of diamond films by Electron-assisted Chemical Vapor Deposition (EACVD). The results show that the hot-filament parameters have great influence on the magnitude of the substrate temperature, the results also show that the hot-filament number, the substrate swing angle and the distance between the hot-filament and the substrate affect the uniformity of the substrate temperature field deeply. Diamond deposition experiments show that the uniform temperature field for the growth of the diamond can be obtained by optimizing the parameters of the hot-filament and the swing substrate.
Progress in One-Pot Synthesis of Methyl Isobutyl Ketone Using Multifunctional Layered Based Catalysts
Authors: Das Nigamananda
Published: July 2013

Methyl isobutyl ketone (MIBK) is one of the most widely produced and used aliphatic ketones worldwide. The one-step MIBK process with no intermediate separation steps using multifunctional catalysts is an important development towards greener organic synthesis and generates tremendous interest among the researcher across the globe. The single step process is facile and more economically viable and has provided opportunity to develop new and improved catalyst systems capable of operating under mild conditions. A widely variety of catalytic systems have been used in one-step process during last three to four decades. The progress in one-pot synthesis of MIBK using different multifunctional catalysts with special reference to layered based catalysts was critically reviewed in this article.
Influence of Tool Geometry and Machining Parameters on the Surface Quality and the Effect of Surface Quality on Compressive Strength of Carbon Fibre Reinforced Plastic
Authors: Haddad Madjid , Zitoune Redouane , Eyma Florent , Castanié Bruno
Published: July 2013

In this chapter the influence of tool geometry and cutting conditions on cutting forces, surface defects and the percetage of dust generated durring trimming and reaching the pulmonary alveoli is investigated. The surface defects were analysed using a scanning electron microscope and diferent surface roughness measurement devices. It was observed that these leters were highly depend on the cutting condition and the tool geometry, and more important that the effect of cutting parameters can be completely diferent from a tool to an other or even when considering different ranges of cutting parameters (standard cutting speed and high cutting speed). The compressive strenght after machining is also investigated. It is observed that whatever tool geometry, cutting conditions, surface roughnesses (defects) are, the response still the same for all the composite samples except for those machined at cutting temperatures higher than the glass fiber transition.
Analysis of Stresses in CFRP Composite Plates Drilled with Conventional and Abrasive Water Jet Machining
Authors: Saleem M. , Bougherara Habiba , Toubal L. , Cénac F. , Zitoune Redouane
Published: July 2013

The aim of this paper is to analyze the influence of two machining processes on the mechanical behaviour of composite plates under cyclic loading. For this purpose, an experimental study using several CFRP plates drilled with conventional machining and non-conventional machining (abrasive water jet) was carried out. Digital image correlation and static tests using an Instron 4206 tester were performed. In addition, infrared thermography (IR) and fatigue tests were also performed to assess temperature and damage evolutions and also the stiffness degradation. Fatigue results have shown that the damage accumulation in specimens drilled with conventional machining was higher than the abrasive water jet ones. Furthermore, the endurance limit for plates drilled conventionally was approximately 10% higher than those drilled with abrasive water jet. This difference was related to the initial surface integrity after machining induced by the difference in the mechanism of material's removal between the two processes. The difference in surface texture was responsible for the initiation of stress concentration sites as evident from IR camera’s stress analysis. This was confirmed by SEM tests conducted after a destructive sectioning of the specimens before fatigue testing.
Multi-Objective Optimization on Drilling of Titanium Alloy (Ti6Al4V)
Authors: Prabukarthi A. , Krishnaraj V. , Senthil Kumar M.
Published: July 2013

Titanium alloys present superior properties like resistance to corrosion, high strength to weight ratio etc, but possess poor machinability. Titanium alloy Ti-6Al-4V is the most commonly used titanium alloy in aerospace and medical device industries. Titanium and its alloys are notorious for their poor thermal properties and are classified as difficult-to-machine materials. Drilling is an important machining process since it is involved in nearly all titanium applications. It is desirable to develop optimized drilling processes for Ti and improve the hole characteristics such as hole diameter, circularity and exit burr of currently available processes. Due to the low machinability of the alloys under study, selecting the machining conditions and parameters is crucial. The range of spindle speed and feed rate, which provide a satisfactory tool life, is very limited. The hole quality (hole diameter and circularity), thrust force, torque and exit burr were evaluated at various spindle speeds, feed rates combinations. The optimized parameter is chosen using the multi-objective weighted sum optimization technique.
Study of the Effect of Cooling Rate on Eutectic Modification in A356 Aluminium Alloys
Authors: Ferdian Deni , Lacaze Jacques , Lizarralde Ibon , Niklas Andrea , Fernandez-Calvo Ana Isabel
Published: July 2013

In this present work, an assessment of eutectic modification based on thermal analysis was performed on modified A356 alloy. The effect of various cooling rates which were achieved by means of casting samples with various moduli in sand and metallic moulds was investigated. Cooling curves recorded from thermocouples inserted in the centre of the samples showed characteristic undercooling and recalescence associated with (Al)-Si eutectic modification. The results showed that cooling rate has a role in observed modification level. Furthermore, differential thermal analysis was included to determine the eutectic melting temperature.
Focused Ion Beam Milling and Imaging: An Advanced Method to Detect Fine Inclusions in Cast Aluminium Alloys
Authors: Kim Kee Hyun , Green Nick R. , Griffiths William D.
Published: July 2013

The combined function of a FIB milling technique utilising beam sizes of under 10 nm coupled with a micromanipulator and FIB imaging enables analysis of the microstructure of samples and fabrication of TEM thin foils. This is accomplished at desired locations in the same chamber without moving the sample or any mechanical sawing and thinning. In this study, the FIB milling and imaging technique was used to examine the microstructure and chemical composition of fine inclusions in an Al alloy, which are generally difficult to detect by conventional optical and/or scanning electron microscopy due to their size and volume fraction. Examples are presented of fine particles in cast commercial purity aluminium and a melt conditioned AA 5754 alloy.
DC Casting of Large Sized Ingot of a High Strength 7xxx Alloy under the Influence of Electromagnetic Field
Authors: Cui Jian Zhong , Zhang Hai Tao , Zuo Yu Bo
Published: July 2013

Hot tearing and cold cracks are major defects during direct chill (DC) casting of large sized ingots of high strength aluminium alloys. In order to solve these problems, based on a low frequency electromagnetic casting (LFEC) process, a new technology, electromagnetic casting with the application of an air blade (EMA) was developed. In the present work, this new technology was used to prepare large sized AA7055 aluminium alloy ingots and the effects of the low frequency electromagnetic field and the air blade on macro-physical fields, microstructure and cracking are studied by numerical and experimental methods. The results show that applying an electromagnetic field can modify the flow direction, increase the velocity of melt flow and homogenize the distribution of temperature in the sump. Applying an air blade can homogenize the distribution of temperature and decrease the stress and strain in the solidified ingot. Furthermore, the microstructure of the ingot is refined remarkably and cracking is eliminated by simultaneously applying the electromagnetic field and the air blade during DC casting.
A Synchrotron X-Ray Radiography Investigation of Induced Dendrite Fragmentation in Al-15wt%Cu
Authors: Liotti Enzo , Lui Andrew , Vincent Robin , Kumar Sundaram , Guo Zhi Peng , Connolley Thomas , Hart Michael , Arnberg Lars , Mathiesen Ragnvald H. , Grant Patrick S.
Published: July 2013

The effect of a Pulsed Electro Magnetic Field (PEMF) on the solidification of an Al‑15 wt%Cu alloy was studied in situ by synchrotron X-ray radiography. Samples were solidified with and without the presence of the PEMF while recording radiographs, enabling observation and quantification of dendrite fragmentation by image analysis. Fragmentation increased with a PEMF and was attributed to induced inter-dendritic flow.
A Finite-Volume Model for Numerical Solidification of Mg Alloys
Authors: Farrokhnejad Mehdi , Straatman Anthony , Wood Jeffrey
Published: July 2013

Solidification of a wedge casting of magnesium alloy AZ31 in the presence of melt convection is investigated. The formulation used in the in-house code is developed based on the finite-volume method on unstructured grids and utilizes a colocated finite-volume framework. In the discretization of the mass and momentum equations all novelties proposed in [1] are implemented and a source based-energy equation is presented. The volume fraction of solid in the domain and the cooling rates at six different embedded thermocouples are predicted. These results are compared to previous experimental work and against similar results obtained with a widely used commercial software package.
Effect of Addition of Al & Ca and Heat Treatment on the Cast Mg-6Zn Alloy
Authors: Joshi S.S. , Mohan M.S. , Seshan S. , Kumar S. , Suwas S.
Published: July 2013

In the present investigation, the effect of addition of Al and small amounts of Ca as well as the effect of heat treatment has been investigated on microstructure, tensile properties and corrosion behaviour of Mg-6Zn alloy produced by squeeze casting. The Mg-6Zn-1Al (ZA61) alloy consisted of α-Mg grains and MgZn (β) phase at the grain boundaries with a much higher strength and ductility than pure Mg. The addition of 0.1 and 0.5 wt% Ca to the ZA61 alloy refined the grain size and increased the volume fraction of the grain boundary phase but did not change the nature of the phase. Consequently, strength increased without much reduction in ductility. The increase in Al content of the alloy to 4 wt% (ZA64) changed the grain boundary phase to Al5Mg11Zn4 (Φ) phase, increased its volume fraction and refined the grain size as compared to ZA61 alloy. Consequently, strength increased with a reduction in ductility. On heat treatment of ZA61+0.5Ca and ZA64 alloys, the volume fraction of grain boundary phases decreased, fine precipitates were obtained in the matrix and the grain size increased. Thus, higher strength with a lower ductility was obtained on heat treatment but the ductility of both the alloys was still higher than that of pure Mg. Thus, 130 MPa 0.2%PS, 225 MPa UTS and 4.9% elongation to fracture could be obtained for the squeeze cast ZA64 alloy in the T6 condition, which are very good tensile properties for a cast Mg alloy. Increase in Al content and heat treatment reduced the corrosion resistance and addition of Ca improved it. The highest corrosion rate was observed to be 0.85 mm/year for the ZA64 alloy in the T6 condition.
Design of a Composite Roll with Internal Cooling Channels for Twin-Roll Casting
Authors: Park Jong Jin
Published: July 2013

In twin-roll casting, the melt is cooled, solidified and rolled to a specific thickness only by the rolls and consequently a lot of heat is transferred from the melt to the rolls through the melt/roll interface. In a composite roll, consisting of a steel core and a copper-alloy sleeve, the heat is finally removed by cooling water flowing through internal cooling channels. In the present study, design of the channels was improved using finite-element analysis in the aspects of structural as well as fatigue strengths.
Cryo-Rolling and Formability of 2024 Aluminium
Authors: Taylor Adam S. , Weiss Matthias , Hilditch Tim , Hodgson Peter D. , Stanford Nicole
Published: July 2013

Sheets of precipitate hardenable 2024 aluminium have been processed by rolling at liquid nitrogen temperature in order to refine the microstructure. A number of different aging/heat treating procedures have been utilised that have resulted in significantly different mechanical properties. The cryo-rolled material was heat treated at 150 °C for varying times and the resulting mechanical properties evaluated as a function of this holding time. The resulting properties were found to be strongly influenced by precipitates that formed either during the aging step, rolling process or the subsequent heat treatment. The formability of the cryo-rolled and heat treated material has been investigated using a limiting dome height test (Erichsen cupping test).
The Effect of Particles on Microstructure and Mechanical Behaviour of Mg-10Gd-3Y-0.4Zr Alloy Processed by ECAP
Authors: Zhou Yin Peng , Li De Jiang , Zeng Xiao Qin , Ding Wen Jiang
Published: July 2013

An Mg-10Gd-3Y-0.4Zr alloy (GW103K) was processed by equal-channel angular pressing (ECAP) for 1-6 passes at 663 K; and the evolution of microstructure during ECAP was studied by OM and XRD. After ECAP, the grain size was reduced from 65 μm (initial state) to 4.2 μm (6 passes), the β equilibrium phase precipitated gradually and the area fraction of β phase increased from 0.8% to 13.4%. The distribution of fine grain zones and second phase particles were coincident, which was consistent with PSN. During the ECAP process, the yield strength increased up to a peak and then decreased, and the elongation increased firstly, then decreased later and increased again. The optimal mechanical properties were obtained after 3 passes, which was attributed to the combined effect grain refinement and second phase particle strengthening.