bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface Integrity in Hot Machining of AISI D2 Hardened Steel
Authors: Lajis Mohd Amri , Amin A.K.M. Nurul , Karim A.N. Mustafizul
Published: April 2012

This study presents experimental results of machined surface integrity of die material (AISI D2 hardened steel) when hot machining (induction heating) assisted end milling using coated carbide is applied. The aim of this work was to study the influence of induction heating temperature, cutting speed, and feed on the effects induced by hard milling on surface integrity (microhardness and work-hardening). Microhardness was measured to observe the distribution of the hardness beneath the surface and to determine the effect of induction heating on the micro-hardness distribution and work-hardening phenomena. The behaviour of microhardness induced in the subsurface region when end milling under room and induction heating cutting conditions using coated carbide inserts was also investigated. The surface integrity and subsurface alteration have been investigated by employing scanning electron microscope (SEM) and Vickers microhardness tester.
Conversion Topology and Reconstruction in the Field of Robotics and Machine Tools
Authors: Hou Fei , Wang Jing Kun , Zhang Shan Yong
Published: April 2012

The current domestic and international structure of reconfigurable robot and reconfigurable machine tool have been studied by us, their topological characteristics and methods of conversion were summed up, the method of reconfigurable machine to converter topology was found to achieve the purpose of reconstruction of the machine comparing the two different areas of the module types and functions.
Multi-Objective Optimization of Product Configuration Based on Customer's Performance Satisfaction
Authors: Fan Zhi Jun , Jiang Zhao Liang , Li Zhi
Published: April 2012

The aim of product configuration is to satisfy the customer's personality requirements with low manufacturing cost. Based on the relationship of customers performance requirements and satisfaction, a method of product configuration optimization was proposed. The customers performance requirements are divided into three types with Kanos theory. A multi-objective genetic algorithm with objectives of performance satisfaction, manufacturing cost and lead time was designed to solve this multi-objective optimization problem. A case study is conducted to demonstrate the effectiveness of the proposed approach.
Wireless Control System of Reconfigurable Flexible Process-Equipment
Authors: Zhou Liang , Fang Yan Tao , Cao Gang , Zhu Bo
Published: April 2012

The reconfigurable flexible process-equipment developed for machining complex shape and size changes in the scope of large thin-walled parts usually consists of dozens or even hundreds of positioning/support units. During the control process, each unit communicates with the host computer to get control commands and simultaneously feedback internal state information. For large complex system composed of many subsystems, the traditional cable connection based on field bus technology is high control costs and the complexity of the control circuit is hard to build and manage. To solve this problem, this paper puts forward a new way of wireless communication with the cable network technology and drive positioning/support unit in order. This paper focuses on the overall structure of the proposed system, host computer control system, lower computer control system and wireless communication module as well as the implementation hardware circuits and software algorithm. In addition, some solutions of related issues are discussed. The research shows that the proposed system has high stability and reliability, and it provides an effective way to the control and communication of complex system which fully meets the requirements of reconfigurable flexible process-equipment.
Experimental Investigation on Surface Integrity of End Milling Nickel Based Alloy-Inconel 718
Authors: Cai Xiao Jiang , Qin Sheng , An Qing Long , Chen Ming
Published: April 2012

nconel 718 is a typical difficult-to-machine material, and its high speed end milling process has wide applications in manufacturing parts for aerospace and power industry. Surface integrity of these parts greatly influences the final characteristics. This paper presents an experimental investigation to evaluate surface integrity behaviors of Inconel 718 with finishing cutting parameters in terms of surface topography, surface roughness Ra, residual stresses and subsurface microstructure and microhardness. The results show that high cutting speed is advisable to get better surface topography and roughness. Residual stresses and subsurface microhardness barely increase after 80m/min. Microstructure in surface layer has only slight deformation after high speed milling.
Three Dimensional Monte Carlo Simulation of Microstructure Evolution in Presence of Pores and Impurities for Three-Phase Nanocomposite Ceramic Tool Materials
Authors: Hao Song , Huang Chuan Zhen , Zou Bin , Wang Jun , Liu Han Lian , Zhu Hong Tao
Published: April 2012

A modified three-dimensional Monte Carlo (MC) model in presence of pores and impurities for three-phase nanocomposite ceramic tool materials is successfully established in this paper. Pore migration by surface diffusion is incorporated into the MC model and it is applied to observe and scientific quantitative characterization of three dimensional microstructure evolution and densification process. Some modifications are applied to the simulation algorithm to improve the computing efficiency. The influence of pores on the particle and impurity loaded grain boundaries is simulated and investigated for the study of grain growth kinetics. The relationship between porosity and density is also analyzed. The results indicate that the higher the porosity is, the lower the density will be.
Research on Solid Modeling and a Different Mode of Loading with Finite Element Analysis for Flat End Mill
Authors: Liu Qing Shan , Tan Guang Yu , Liu Guang Jun , Su Yan Li , Li Guang Hui
Published: April 2012

This work aims to investigate parameterized modeling and a different mode of loading with finite element analysis for flat end mill. A loading mode is chosen according to the cutting force model of overall end mills. Normal and shear stresses which calculate from the cutting force experiments are loaded on the rack face of flat end mill. The stress distribution of end mill in high-speed cutting is obtained by finite element analysis. It is shown that the maximum stress is located at major flank face near the tool tip, rather than the nose of tool and the chisel edge. It shows the tool breakage mechanism in the local region. In the end, we compared the finite element analysis results with the experiment ones. It indicates that the analysis results agree well with the experimental data. Therefore, the proposed loading mode is available.
Experiments and Finite Element Simulations on Micro-Milling of Aluminium Alloy 7050-T7451
Authors: Wang Fu Zeng , Sun Jie , Zhou Jun , Li Jian Feng
Published: April 2012

The mechanism of micro-milling modeling for aluminum alloy 7050-T745 is to be investigated, and a finite element model for micro-milling that reflects the actual state of the three-dimensional micro-milling is built by adopting the software of ABAQUS/Explicit. Experiment is conducted to verify the validation of the model. Simulated chip morphology in different cutting parameters agrees to the experimental results very well. Based on the FE model, cutting stresses, equivalent plastic strains, temperatures distribution and cutting forces are obtained and analyzed. This provides a good method to investigate the micro milling principles.
Stability Analysis of Fractional Delay Differential Equations by Lagrange Polynomial
Authors: Zhang Xiang Mei , Xu An Ping , Guo Xian Zhou
Published: April 2012

The paper deals with the numerical stability analysis of fractional delay differential equations with non-smooth coefficients using the Lagrange collocation method. In this paper, based on the Grunwald-Letnikov fractional derivatives, we discuss the approximation of fractional differentiation by the Lagrange polynomial. Then we study the numerical stability of the fractional delay differential equations. Finally, the stability of the delayed Mathieu equation of fractional order is studied and examined by Lagrange collocation method.
Effect of SiO2 Particle Concentration on the Tribological Properties of PTFE Sealing Material
Authors: Zhang Yan Liang , Zhou Jun , Deng Jian Xin
Published: April 2012

Oil suspension was made with different concentrations of SiO2 particles.The effects of SiO2 with different concentrations on frictional pairs 45# -PTFE under different velocities is investigated on MRH-3 abrasion tester. The worn of PTFE surfaces was investigated by scanning electron microscopy (SEM).The results show that the friction coefficient increases with increasing SiO2 concentrations. The wear rate increases with the increasing particle concentration and then decreases a bit. Meanwhile the degree of wear increases with increasing particle concentrations. Furthermore, as shown in SEM micrographs, the main machenism of PTFE is furrowing wear.
Improved Tensile Strength of Carbon Nanotube Reinforced Aluminum Composites Processed by Powder Metallurgy
Authors: Liao Jin Zhi , Tan Ming Jen
Published: April 2012

Carbon nanotube (CNT) reinforced aluminum (Al) composites were synthesized using the powder metallurgy (P/M) technique, combined with hot extrusion and hot rolling. 0-2.0wt.% of CNTs were added as reinforcements. The effect of CNTs on the mechanical properties of Al was investigated and a significant enhancement in tensile strength was obtained compared with the pure matrix. The improved strength was analyzed based on (i) Orowan strengthening, (ii) thermal mismatch between CNTs and matrix, and (iii) load partition effect due to the CNTs.
Microstructure and Mechanical Properties of Ti(C,N)-TiB2-WC Composite Ceramic Tool Materials
Authors: Liu Yue , Huang Chuan Zhen , Liu Han Lian , Zou Bin , Shi Qiang
Published: April 2012

Ti (C,N)-TiB2-WC composite ceramic tool materials with sintering aids such as Ni and Mo were fabricated at a temperature of 1550 °C for 1h sintering duration time in vacuum by a hot-press technique. The microstructure and mechanical properties were investigated. The composite ceramic tool materials were analyzed by means of scanning electron microscope (SEM), X-ray diffraction (XRD) and energy dispersive spectrometry (EDS). The main phases were composed of Ti (C, N), TiB2,WC and MoC, which indicated that no severe chemical reactions occurred in the composite. The flexural strength, fracture toughness and hardness of Ti (C,N)- 20 wt.%TiB2-WC ceramic material were 795.7 MPa, 6.4 MPa·m1/2and 19.2 GPa respectively.
Influence of Different Deformation on Microstructure and Properties of 304 Austenitic Stainless Steel
Authors: Han Fei , Lin Gao Yong , Li Qian , Long Rui Fen , Peng Da Shu , Zhou Qing
Published: April 2012

In this paper, a kind of 304 austenitic stainless steel sheets has been investigated, and systemic tests were conducted to study the law and mechanics of work hardening of 304 austenitic stainless steel. The results of microstructure analyzing of 304 austenitic stainless steels showed that when it was deformed by means of tensile testing at room temperature, obvious work hardening was caused by the changes of structure during the deformation. The strain-induced α-martensite, ε-martensite and deformation twins enhanced flow stress obviously, which is the main reason for the strong work hardening in FCC metals and alloys with low stacking fault energy as 304 austenitic stainless steel.
The Simulation Research of Nano-Indentation Based on the Molecular Dynamics
Authors: Zhu Ying , Xie Ling Ling , Song Sen , Qi Shun Hen , Liu Qian Qian
Published: April 2012

The work in the optimization of the simulation of nanoindentation based on the molecular dynamics was mainly introduced in this paper. One optimization method, freeze atoms method was proposed according to the characteristics of nanoindentation process itself, then did the simulation calculation through the use of freeze atoms method and the traditional calculation method, It was found that the difference between simulation results and experimental results of hardness decreased gradually with enlarge the scale of molecular dynamics simulation (with increase of the indentation depth), from 32.39% of 5nm decreased to 14.6% of 25nm. By comparison, it was found that the optimized algorithm could improve the efficiency of simulation in large-scale molecular dynamics simulation., confirmed the correctness and effectiveness of freeze atoms method.
Luminescence Properties of Magnesium Phosphate Glass Doped Samarium
Authors: Sahar M.R. , Yusoff Nurulhuda Mohammad , Ghosal S.K. , Rohani M. Supar , Hamzah Khaidzir , Arifin R.
Published: April 2012

Samarium doped magnesium phosphate glass having a composition of [P2O5]50-x-[MgO]50-[Sm2O3]x, with 0≤x≤4 mol% were prepared by melt-quenching method. The emission spectra were recorded using the photoluminescence spectrometer in the range of 540-730 nm at room temperature after being excited at 403 nm. It was found that the emission spectrum of Sm3+consisted of four emission bands at ~559.76 nm, ~597.32 nm, ~641.55 nm and ~705.57 nm which were assign as a transition of 4G5/2→6H5/2, 4G5/2 →6H7/2, 4G5/2→6H9/2 and 4G5/2→6H11/2 respectively. The transition of 4G5/2→6H7/2 is detected as the strongest orange (597.32 nm) luminescence peaks thus dominates the transition.
Luminescence Spectra of TeO2-PbO-Li2O Doped Nd2O3 Glass
Authors: Azman K. , Razali W.A.W. , Azhan H. , Sahar M.R.
Published: April 2012

A tellurite glass of TeO2-PbO-Li2O doped with Nd2O3 has been successfully fabricated by using the conventional melt-quenched technique. The absorption and emission spectroscopy have been identified using UV-VIS-NIR and photoluminescence spectrometer, respectively. From the spectroscopy, ten significant spectra have been observed in the region of 400-900 nm. The absorption wavelength centered at 585 nm attributed to 4I9/2 → 4G5/2 transition is the predominant wavelength to be used as the excitation wavelength. Emission spectra have been determined by using 585 nm excitation wavelength at room temperature. From the emission spectra, seven distinctive upconversion bands contributed from Nd3+ were observed in the region of 400-1500 nm. It was found that the bands were centered at 450 nm (4G11/2 → 4I9/2), 485 nm (4G11/2 → 4I11/2), 605 nm (4G11/2 → 4I15/2), 665 nm (4G7/2 → 4I13/2), 880 nm (4F3/2 → 4I9/2), 1062 nm (4F3/2 → 4I11/2) and 1340 nm (4F3/2 → 4I11/2), respectively. Tthese emission bands showed the possibility of visible and near infrared emission spectra.
Enhanced Infrared to Visible Upconversion Emission in Er3+ Doped Phosphate Glass Containing Silver Nanoparticles
Authors: Amjad Raja J. , Sahar M.R. , Ghoshal S.K. , Riaz S.
Published: April 2012

Phosphate glasses containing fixed concentration of rare-earth with and without metallic nanoparticles (NPs) having compositions (59.5-x) P2O5-MgO-xAgCl-0.5Er2O3, where 0 ≤ x ≤ 1.5 mol% was prepared using melt-quenching technique. Spectral characterizations were made using UV-VIS-IR spectroscopy and photoluminescence spectroscopy. Addition of silver NPs enhanced the corresponding absorption and was optimum at 1.5 mol% AgCl. Infrared to visible frequency upconversion (UC) emission were observed in the glass on pumping with 797 nm radiation. Furthermore, it was found that the emission at 540 nm, due to Er3+transition (4S3/2-4I15/2) was much more influenced by the silver NPs in comparison to the emission at 632 nm (4F9/2 - 4I15/2). These enhancements were attributed to the local fields present in the vicinity of silver NPs. Moreover, the rapid increase in the intensity of the green band as compared to the red band was due to the charge cloud effect of the plasmon band. Since green band lie more close to the plasmon frequency band of Ag and hence showed rapid increase compared to the far lying red bands. Our findings may contribute towards the development of solid state laser and sensors
Wetting and Intermetallic Study between Sn-3.5Ag-1.0Cu-xZn Lead-Free Solders and Copper Substrate (x = 0, 0.1, 0.4, 0.7)
Authors: Mayappan Ramani
Published: April 2012

The development of lead-free solders has been an essential task in the electronics industry because of the restriction of lead use by legislation. Among the candidates, Sn-Ag-Cu group of solder alloys have great advantages to replace the conventional Sn-Pb solder. In this study, the wetting and intermetallic study between Sn-3.5Ag-1.0Cu-xZn lead-free solder reacting on copper substrate were investigated under different soldering conditions. The addition of 0.7wt% of Zn improved the wettability on Cu substrate since it has the highest spreading area at 310°C. The Cu6Sn5 and Cu3Sn phases are the main interface intermetallic formed and these intermetallics increased in thickness with time and temperature. At 270°C, the addition of 0.7wt% Zn retarded the growth of Cu3Sn intermetallic until 10 min of the soldering time. Generally the addition of Zn was beneficial in retarding the total intermetallic thickness.
Characterization of Sn-3.5Ag-1.0Cu Lead-Free Solder Prepared via Powder Metallurgy Method
Authors: Yahya Iziana , Ab Ghani Noor Asikin , Mohd Salleh Mohd Arif Anuar , Abd Hamid Hamidi , Ahmad Zainal Arifin , Mayappan Ramani
Published: April 2012

The toxicity in the Sn-Pb solder has promoted the development of Pb-free solder in the electronics industries. Among the Pb-solders, the Sn-3.5Ag-1.0Cu solder is considered a potential replacement and being studied by many researchers. In the present study, the characteristics of Sn-3.5Ag-1.0Cu lead-free solder were studied. The raw materials were tin, silver and copper powders in micron size. The solder was prepared using powder metallurgy route which includes blending, compacting and sintering. Four blending times and two compacting pressures were used to investigate for optimum condition. The melting temperature of the samples were studied using differential scanning calorimeter (DSC) and the presence of Sn Ag, Cu were confirmed using x-ray diffraction analysis (XRD). Finally the effect of variables on the hardness of the solders is reported.
High Temperature Corrosion of Fe-30Cr in Flowing CO2 Gas
Authors: Atikah S. Nurul , Othman Norinsan Kamil , Jalar Azman
Published: April 2012

A plate of Fe-30Cr (wt%) were subjected to isothermal furnace at 600 °C in flowing CO2 gas at total pressure of approximately 1 atm. The reacted samples morphology and microstructure were characterized by using visual inspection, optical microscope, SEM and EDAX. The weight change measurement showed a fluctuating result during the exposure. The significant weight loss was observed after five hours exposure due to oxide scale exfoliation. Formation of different oxide and element presents on the interface of the specimen such as Cr2O3, C and Fe3C were revealed by X-ray diffraction and with supported by EDAX analysis. This behavior of the high temperature corrosion on Fe-30Cr was discussed based on morphology and microstructure observation.
Photoluminescence and Raman Studies of Annealed ZnO Nanostructures
Authors: Mohd Bakhori Siti Khadijah , Ling Chuo Ann , Mahmud Shahrom
Published: April 2012

The influence of annealing on the optical properties of as-grown ZnO nanostructures prepared in pellets has been investigated by photoluminescence (PL) and Raman spectroscopy. The annealing temperatures of ZnO nanostructure at 600°C, 650°C and 700 °C were conducted in oxygen (O2) and nitrogen (N2) ambient. The near band edge emission (NBE) of samples recorded in the PL spectra demonstrates significant changes on optical signal whereby the NBE is redshifted after O2 annealed and became slightly higher in N2 annealed. Apart from that, weak green luminescence (GL) namely deep band emission (DBE) is observed centre at 532.95 nm (2.23 eV) and 511.00 nm (2.42 eV) for annealed in O2 and N2 respectively, whereas lower DBE observed in as-grown ZnO. On the other hand, Raman shift reveal the phonon mode of the ZnO nanostructures and the E2 (high) mode were downshifted as annealed in O2 ambient, and upshifted in N2 ambient. The downshift and upshift of the E2 (high) mode are correlated to tensile and compressive stress. Moreover the crystallite sizes were calculated from FWHM of XRD and TEM microscopy reveals the nanoplates structure of ZnO nanostructures.
Mechanical Properties of TPNR-MWNTs-OMMT Hybrid Nanocomposites
Authors: Tarawneh Mou'ad A. , Ahmad Sahrim H. , Shamsul Bahri A.R. , Jiun Yu Lih
Published: April 2012

This paper discusses the processing of a hybrid of TPNR-MWNTs-OMMT nanocomposites with different percentages of filler to determine the optimum mechanical properties of the hybrid nanocomposites. Three types of hybrid nanocomposites with various MWNTs-OMMT compositions (1%wt MWNTs+3%wt OMMT), (2%wt MWNTs+2%wt OMMT) and (3%wt MWNTs+1%wt OMMT) were prepared. The OMMT layers were found to be separated further with higher nanotubes content as exhibited by X-ray diffraction. The result of tensile test showed that tensile strength and Young's modulus increase in the presence of nanotubes and maximum value were obtained for the nanocomposites with highest nanotubes (3%wt) which increased about 33% and 36%, respectively compared with pure TPNR matrix. On other hand, the elongation at break considerably decreased with increasing the percentage of MWNTs. TEM micrographs revealed aspect ratio and fillers orientation in the TPNR matrix also promoted strongly to interfacial adhesion between fillers and the matrix which contributed significantly to the improvement of the mechanical properties
Effect of Eosin-Y Coating Temperature on the Performance of Inverted Bulk Heterojunction Organic Solar Cells
Authors: Ginting Riski Titian , Yap Chi Chin , Yahaya Muhammad , Salleh Muhamad Mat
Published: April 2012

Inverted type bulk heterojunction organic solar cell based on ZnO nanorod arrays have been used to overcome the degradation problem of conjugated polymer and low work function electrode. ZnO nanorods and Eosin-Y are widely used to increase the charge mobility and light absorbance, respectively. The effects of Eosin-Y coating temperature (30 – 50 oC) on the performance of organic solar cells based on a blend of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEHPPV) as donor and (6,6)-phenyl-C61 butyric acid methyl ester (PC61BM) as acceptor with a structure of fluorine-doped tin oxide (FTO)/Eosin-Y coated ZnO nanorod arrays/MEHPPV:PCBM/Ag were investigated. By using FTO as a substrate, sol-gel and spin coating method was used to deposit ZnO seed layer on FTO surface. The ZnO nanorods were then grown on the ZnO seed layer by chemical bath deposition method and coated with dye by immersing the substrates into Eosin-Y solution at different temperatures. The result shows that absorption of Eosin-Y coated ZnO nanorods increased with dye coating temperature. The optimum power conversion efficiency of η = 1.24 × 10-2 % was achieved at dye coating temperature 50 oC under 100 mW/cm2 simulated AM 1.5 G sunlight.
Influence of Na, Mg and Yb Substitution for Ca in Bi(Pb)-2223 Superconductor
Authors: Hawa J.S. , Azhan H. , Yahya S.Y.S. , Azman K. , Hidayah H.N. , Norazidah A.W.
Published: April 2012

The effect of Ca substitution by Na, Mg and Yb on the structural and transport properties of Bi1.6Pb0.4Sr2Ca2-xMxCu3Oy (M = Na, Mg and Yb) (x = 0.0 and 0.2) superconducting samples have been investigated. The samples were prepared by the coprecipitation (COP) method. The samples were characterized by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), electrical resistivity measurement and critical current density. The critical current density (Jc) and transition temperature (Tc zero) of Na, Mg and Yb substituted with x = 0.2 were found to be lower than the pure sample. Tc zero varies between 100 K and 63 K. Mg concentration was found to give the highest Tc zero of 93 K. Tc zero gradually decreased from Mg, Yb to Na corresponding to a small change in the carrier concentration. Jc decreased with Mg, Yb and Na substitution, and it was measured to be 7.4611 A/cm2, 0.0667 A/cm2, 1.4579 A/cm2 and 1.2479 A/cm2 for pure, Na, Mg and Yb substitution, respectively at 60 K. XRD analysis showed that the decrease of the volume fraction for the 2223 phase and increase of the volume fraction for the 2212 phase with substitution of Na, Mg and Yb. The proportion of Bi-2223/Bi-2212 (%) was estimated from 78.13/21.87 for pure to 51.71/48.29 for Na substitution.
Superconducting Properties of Calcium Substitution in Barium Site of Porous YBa2Cu3O7 Ceramics
Authors: Norazidah A.W. , Azhan H. , Azman K. , Hidayah H.N. , Hawa J.S.
Published: April 2012

The influence of calcium substitution at the barium site of porous Y(Ba1-xCax)2Cu3Oδ (x= 0.00, 0.10, 0.20 and 0.30) samples prepared via solid-state reaction method have been investigated. The structure, morphology, critical temperature and critical current were determined by x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and four-point probe method, respectively. Generally, the curves of normalized resistance for all samples displayed normal metallic behavior above Tc onset. The Tc zero was between 84 K and 71 K with increase in Ca concentration corresponding to a small change of carrier concentration. The critical current density, Jc decreases with increase in Ca concentration. The highest Jc of 2.657 A/cm2 at 50 K was obtained in Ca-free porous YBCO which is higher than that of Ca-free non porous YBCO. Further substitution of Ca at Ba site decreased Jc monotonously. The increase of Ca concentration decreased the volume of unit cell but the crystallographic structure remains in the orthorhombic form where a≠b≠c. The grains are highly compacted and randomly distributed while the grain size decreased as the Ca concentration increased.
Effect of Methyl Methacrylate Content in Carbon Black Filled Natural Rubber Compounds
Authors: Rohani Abu Bakar , Mazlina Mustafa Kamal , Mohd Som Fauzi
Published: April 2012

Natural rubber-grafted-poly(methyl methacrylate) containing 30 and 50 percent of methyl methacrylate (MMA) monomer per 100 parts by weight of the dry rubber content denoted as NR-g-PMMA 30 and NR-g-PMMA 50, respectively were prepared via emulsion polymerisation technique. The occurrences of graft copolymerisation of PMMA onto NR were confirmed by proton Nuclear Magnetic Resonance (1H NMR) and Fourier Transform Infrared (FTIR) following purifications. The reinforcement of rubber by fillers is of great practical and technical importance. Thus, these fillers are added to rubber formulations to optimize the properties to meet a given application or set of performance parameters. In this study, the effect of carbon black in NR-g-PMMA 30 and NR-g-PMMA 50 rubber compounds were evaluated. Our results demonstrated that tensile strength, elongation at break and compression set reduced, while the hardness and solvent resistance increased in the presence of carbon black filler in comparison to the unfilled compound.
Thermal Diffusivity and Conductivity of La0.7Ca0.3-xSrxMnO3 (x=0 to 0.10)
Authors: Alwi Hasan A. , Ewe Lay S. , Ibrahim Zahari , Ibrahim Noor B. , Abd-Shukor Roslan
Published: April 2012

We report the room temperature thermal conductivity κ and thermal diffusivity α of polycrystalline La0.7Ca0.3-xSrxMnO3 for x = 0 to 0.1. The samples were prepared by heating at 1220 and 1320oC. The insulator-metal transition temperature, TIM and thermal diffusivity increased with Sr content. Phonon was the dominant contributor to thermal conductivity and the electronic contribution was less than 1%. Enhancement of electrical conductivity σ and thermal diffusivity for x ≥ 0.08 was observed in both series of samples. The grain size of the samples (28 to 46 µm) does not show any affect on the thermal and electrical properties.
Influence of Milling Time on the Crystallization, Morphology and Magnetic Properties of Polycrystalline Yttrium Iron Garnet
Authors: Nazlan Rodziah , Hashim Mansor , Abdullah Nor Hapishah , Ibrahim Idza Riati , Ismail Ismayadi
Published: April 2012

The polycrystalline Yttrium Iron Garnet (YIG) powder with the chemical formula Y3Fe5O12 has been synthesized by using High Energy Ball Milling technique. The effect of various preparation parameters on the crystallinity, morphology and complex permeability of YIG, which includes milling time and annealing temperature were studied respectively by using XRD, SEM and Impedance Material Analyzer. The frequency dependence of complex permeability namely real permeability, µ’ and magnetic loss, µ’’ were measured at room temperature for samples sintered from 600°C to 1400°C, in the frequency range 10 MHz to 1 GHz. The results showed that milling time plays a role in determining the crystallinity of the milled powder where higher milling time results in better crystallinity due to high reactivity of the particles. From complex permeability measurement, it was observed that the initial permeability and magnetic loss increased with increasing grain size. The permeability values increased with annealing temperature and the absolute values of permeability decreased after attaining the natural resonance frequency of the material.
Effect of Sm-Doping on Magnetic and Dielectric Properties of BiFeO3
Authors: Ain R.S.N. , Halim S.A. , Hashim Mansor
Published: April 2012

Polycrystalline Bi1-xSmxFeO3 multiferroic samples in the range 0 ≤ x ≤ 0.1 were prepared via solid state reaction method. The effect of samarium ion (Sm3+) doping at the bismuth site in multiferroic BiFeO3 structure and its relation with magnetic and dielectric properties were investigated. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Vibrating Sample Magnetometer (VSM) and Impedance Analyzer were used to characterize the structure and the properties of the composition. The XRD results showed that all the compounds are rhombohedral distorted perovskite structure (R3C). The average grain size identified by SEM were 2.61 µm and decreased to 1.18 µm by introducing the element of Sm doping. At room temperature, all samples showed a spontaneous magnetization which was enhanced by doping with Sm3+ ion. The dielectric constant and dielectric loss decreased inversely proportional to the frequency from 102 to 106 Hz.
First Principle Study of Dynamical Properties of a New Perovskite Material Based on GeTiO3
Authors: Yaakob Muhamad Kamil , Taib Mohamad Faris M. , Yahya Muhd Zu Azhan
Published: April 2012

The dynamical properties of a new perovskite GeTiO3 materials have been investigated by using first principle calculation based on Density Functional Theory (DFT) within the gradient generalized approximation (GGA). All calculations were performed using the Cambridge Serial Total Energy Package (CASTEP) computer code. The calculations include the structural parameter, Born effective charges, and phonon dispersion. The calculated Born effective charges and phonon dispersion have been analyzed and the possibility of ferroelectric feature in GeTiO3 compounds has been discussed. From the analysis, the calculated Born effective charge ZGe and ZTi showed large anomaly compared to the nominal charge which contributed to the large atomic displacement. The calculated phonon dispersion showed the most unstable mode was at G point and the unstable modes were dominated by Ge branch. The dynamical properties and ferroelectric properties in GeTiO3 are discussed and compared with the ferroelectric feature in PbTiO3.
DFT Applications in Characterizing Electronic Properties of Cadmium Telluride with Relativistic Effects
Authors: Othman Ahmad Puaad , Gopir G.K.A. , Basri Hamizah
Published: April 2012

A computational study using the density fuctional through linear augmented plane wave (LAPW) and gradient generalized approximation (GGA) methods on the electronic properties of cadmium telluride (CdTe) in two modes namely with relativistic effect and non-relativistic effect is presented. Two electronic properties were obtained and compared between the computation with and without the relativistic effects. Firstly, plots of density of states were produced which were for the total CdTe. The total DOS showed that the conduction band was dominated by the states of Te atom, whereas the valence band is dominated by the states of Cd atom. Secondly, the total band structure plot obtained showed that the direct energy band gap, Eg calculated value with relativistic effect was about 1.0 eV while the non-relativistic effect value was 1.8 eV.
Upconversion Luminescent Properties of YVO4:Tm3+, Ho3+, Yb3+
Authors: Sun Jia Yue , Zhu Ji Cheng , Zeng Jun Hui , Xia Zhi Guo , Du Hai Yan
Published: April 2012

YVO4 co-doped with Tm3+/Ho3+/Yb3+ were synthesized by the high temperature solid state method and the optical properties of phosphors were characterized. Intense visible emissions centered at around 475, 541 and 649 nm, originated from the transitions of Tm3+:1G4→3H6, Ho3:5S2/>:5F4 →5I8, Tm3+:5G4→3F4 and Ho3+:5F5→5I8, respectively, have been observed in samples upon excitation with a 980 nm laser diode, and the involved mechanisms have been explained.
Study on Selvage Parameter Based on Silk Fabric Specifications Database
Authors: Yang Xi , Liu Xi Mei , Sun Xue Ke , Feng Cen
Published: April 2012

Based on the silk fabric specifications database, the paper proposes two technological parameters of selvage tightness coefficient and selvage warp density coefficient, and realizes the quantitative relationship of corresponding parameters between selvage and fabric. By making use of thousands data of silk products in the silk fabric specifications database, corresponding programs are wrote to achieve the automated numeration of various selvage parameters .Then the paper discusses three typical silk fabrics which contains eleven subclasses and analyses the distribution of the two parameters, with the comparison of selvage parameters in sub-categories of the same categories. The conclusion can provide a theoretical basis for the silk fabric design and production.
Mixed-Solvothermal Preparation of Mace-Like CdS Nanocrystals
Authors: Xu Ling , Hu Han Mei , Xu Hai Yan
Published: April 2012

Novel mace-like (wolf-teeth clubs) CdS nanostructures were successfully prepared on a large scale using CdCl2•2.5H2O and NH2CSNH2 as starting materials through a convenient mixed-solvothermal route. The as-synthesized products were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDX), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and UV-visible absorption spectroscopy. The experimental results reveal that the morphology of CdS products was greatly affected by the volume ratio of anhydrous ethanol and distilled water. The possible mechanism for the formation of mace-like CdS nanostructures is simply discussed.
The Mathematical Model of the Relation among the Resistance, the Distortion Temperature and the Rate of the Steel in the Plastic Deformation
Authors: Li Hong , You Xiao Lin
Published: April 2012

the hardening curve of the steel in the plastic deformation only considers the influence of the deformation degree on the resistance. This paper, according to the basic theory of plastic processing, proposes out the respective relation between the deformation resistance and the deformation degree, the temperature, as well as the rate. This paper gets the curves of these relations by experiments, summarizes the fundamental equations by simulation and finally deduces the plastic conditional equations relating to the material performance----the tensile strength.
Seismic Behavior of Concrete Filled Circular Steel Tubular Columns Based on Artificial Neural Network
Authors: Wei Hua , Du Yu , Wang Hai Jun
Published: April 2012

Artificial neural network (ANN) is self-adaptability, fault toleration and fuzziness. It is suitable to solve the seismic properties of high strength reinforced concrete columns with concrete filled steel tube core (HRCCFT). A three-layer back-propagation network model is build up to study the seismic properties of HRCCFT. The model is trained according to 30 sets of experimental data. The network convergence is fast. The model is verified by 8 groups of experimental data, the results show the predicted values of displacement ductility are in good agreement with test values. The precision of model is better than that of formula from other reference. This method is good enough to be used as an auxiliary method for structure design.
Experimental Study of Thermal Conductivity of Carbon Fiber Reinforced Cement-Based Composites
Authors: Bian Ya Dong , Hai Ran
Published: April 2012

This paper studies the carbon fiber weight influencing on the thermal conductivity of carbon fiber reinforced cement-based composites. Experiment results show that the thermal conductivity decreases with the increase of carbon fiber weight. It is because that the air bubble results from the proceeding when the carbon fiber adds into cement-based composites. When the carbon fiber weight is less than 1.0%(by mass), the thermal conductivity decreases significantly. And when the weight is more than 1.0%, the decreasing tendency starts to slow down. Based on the experiment data, the functional relationship between the thermal conductivity and carbon fiber weight is obtained by using the fitting method.
Synthesis of Acrylic High-Oil Absorption Resins
Authors: Wang Xiao Hua
Published: April 2012

Through suspension polymerization , the influences of different crosslinking agent, initiator, disperser and reaction temperature on oil absorption rate of cetane methacrylate highly oil absorptive resin were studied. The oil absorption ability of the resin for different oil was investigated. The results show the oil absorption capacity of synthesized resins was good with crosslinker divinylbenzene(DVB), initiator benzoyl peroxide(BPO) and disperser polyvinyl alcohol(PVA). Suitable process conditions were: crosslinker DVB 1.0%, initiator BPO 1.2%, disperser PVA 0.8%, reaction temperature 70°C, and oil absorptive power of obtained resin is about 36.6g.g-1 for CC14.
Study on the Preparation of Flame-Retardant Polyacrylonitrile Fiber by Surface Modification
Authors: Jia Zhao , Yang Yan Gong
Published: April 2012

In this article, a new process was used to make flame resistant polyacrylonitrile (PAN) fibers by surface modification. The effects of the treating conditions during the copper ion treatment, aqueous mixture of hydrazine hydrate treatment and high temperature treatment on the mechanical properties and flammability of the resultant flame resistant fibers were studied. The results showed that the optimum reactiong conditions were: the addition of hydrazine hydrate 20mL, drying time 3min, heating temperature 160°C and heating time 180min.Under these conditions, the flame-retardant PAN fiber with good mechanical properties could be obtained.
Evolution of Recrystallization Texture in Non-Oriented Electrical Steel Containing Copper
Authors: Nan Di , Zeng Yan Ping , Hu Guan Qiao , Zhou Zi Yu
Published: April 2012

The evolution of recrystallization texture in the non-orientation electrical steel containing copper during annealing at 950°C for 3～180s have been studied by EBSD (Electron Backscatter Diffraction) measurements. Goss grains({011}) are nucleated within shear bands in deformed {111} and{111} grains. {111} grains nucleate in deformed {111} grains and new{111} grains nucleate in deformed {111}grains. {111} grains have an evident advantage both in number and growth rate over α grains, thus the controlling of annealing time can contribute to the increase of {011} texture.
Study on Modification of Raw Bamboo Fabric and Dyeing Properties
Authors: Chu Yong Mei , Chen Yu Yue
Published: April 2012

The cellulose of raw bamboo fabric was first prepared by selective oxidation with NaIO4. Then the oxidized raw bamboo fabric was modified by sericin protein solution. The dyeing characteristic was studied. Also, the dyeing effect such as K/S value, color fastness, leveling properties were evaluated and compared with unmodified raw bamboo fabric. The results showed that the dyeing properties of oxidized raw bamboo fabric modified by sericin protein were improved. Furthermore, the whiteness of the modified raw bamboo fabric was decreased and the water absorption property was improved.
Properties of Polyaniline with the Doping of Different Acid
Authors: Wang Xiao Hua
Published: April 2012

Polyaniline(PANI) with the doping of hydrochloride(HC1), aminosulfonic acid (NH2SO3H) or dodecylbenzenesulfonic acid(DBSA) was prepared by in-situ polymerization. Effects of acid content, reaction time, oxidant ammonium persulfate (APS) dosage and reaction temperature on the conductivity of PANI were studied. The resistance and thermal stability of them were compared. Results show that the largest conductivity of HC1-PANI is 1.98 s.cm-1 among them in case the C(HC1)=0.5mol/L, reaction time is 6.0h, n(APS/aniline)=1.0; The conductivity of NH2SO3H-PANI is 0.2s.cm-1 in case the C(NH2SO3H)=1.0mol/L, reaction time is 6.0h, n(APS/aniline)=2.0; The conductivity of DBSA-PANI is 0.98s.cm-1 in case the C(DBSA)=1.0 mol/L, reaction time is 8.0h, n(APS/aniline) = 2.0. The the least resistance of HC1-PANI is 10Ω, and that of NH2SO3H- PANI is the largest of 120Ω. The order of their thermal stability is DBSA-PANI > NH2SO3H-PANI > HC1-PANI before 350°C, that of their thermal stability is inverse when it reaches 350°C.
Effects of Sodium Citrate on MAO Process and Characteristics of Coatings Fabricated on AZ91D Magnesium Alloy
Authors: Wang Shu Yan , Xia Yong Ping , Liu Li
Published: April 2012

Microarc oxidation (MAO) coatings were prepared on AZ91D magnesium alloy in a novel dual electrolyte containing various concentrations of sodium citrate (C6H5Na3O7). The surface and cross-sectional morphologies, coating thickness and surface roughness were characterized by scanning electron microscopy (SEM), layer thickness meter and digital microscope, respectively. The corrosion resistance of coatings was evaluated by electrochemical impedance spectroscopy (EIS). The results showed that both the striking voltage and final voltage decreased gradually with the increase of C6H5Na3O7 concentration. When the C6H5Na3O7 concentration increased, surface roughness increased gradually, while thickness of the coating increased at first and then decreased. The coating formed in the electrolyte containing 5g/L C6H5Na3O7 had a much more uniform and compact microstructure with less micropores and micro-cracks. EIS test showed that the concentration of C6H5Na3O7 mainly affected the corrosion resistance of inner dense layer, and the coating with best corrosion resistance was obtained in the electrolyte containing 5g/L C6H5Na3O7.
The Dynamic Dual Vector Finite Element Method for Electromagnetic Waveguide Problem
Authors: Zhu Bao , Zhong Wan Xie
Published: April 2012

The dynamic finite element method is widely used in vibration structural analysis of engineering, and especially advantageous in high frequency vibration analysis comparing with traditional finite element method. It is the same with the electromagnetic waveguide problem. This paper studies the cut-off frequency and the propagation constant problem of waveguide by using the dynamic finite element format which is deduced through dual variational principle and the W-W algorithm. Compared with the common dual edge element method, this one can work out the propagation constant, cut-off frequency and modal more accurately, as well as with small degree of freedom.
The Rolling Forming Principle and the Deformation Analysis of the Ring Multi-Mandrel Roller
Authors: Li Hong , Bai Kun Ju
Published: April 2012

this paper, focusing on the actuality and the features of the cold ring rolling, studies the forming principle of the rolling of multi-mandrel roller. Through the kinematics analysis of the rolling of ring multi-mandrel roller, the deformation simulation and the mechanical analysis of the infinitesimal gridding strain, this paper builds the infinitesimal deformation model of ring blank’s cold rolling, analyzes the deformation rules of the ring blank’s thickness direction rolled by the multi-mandrel roller and the relation between the tangential strain and the radial strain which should be satisfied by the mandrel roller’s movement values, and deduces out the mathematical expressions of the needed technological parameters like the minimum instantaneous rolling reduction. The research result can be used as the theoretical foundations for designing the multi-mandrel rolling miss and working out the rolling technology of the ring multi-mandrel roller.
Research on the Fatigue Strength Test of 20CrMnMo Carburized and Quenched Gears
Authors: Li Wei , Liu Ning , Li Ning , Liu Guo Liang
Published: April 2012

This paper discussed on the research of fatigue strength test of 20CrMnMo carburized and quenched gears. This test is done through a fatigue machine of high-frequency electromagnetic resonant with pulse double-tooth loading. In the short-life area, give four levels of constant stress group test; in the long-life area, adopt up-down test method. According to the experimental data obtained in the tests and statistical theory, complete the C-R-S-N curve, and assess the values of limit stress under different reliabilities.
The Optimal Design of Vertical Hammer Mill Based on Pro/E
Authors: Liu Mei Ying , Yang Rui , Chu Xiu Wen
Published: April 2012

Vertical hammer mill is widely used in food and feed processing factory. It contains the rotor, sieve plate, machine body, feeding device, discharge device, diver device and etc. Traditional design method used two-dimensional drawings to express three-dimensional information of parts, which was abstract and difficult to be modified. This research utilized 3D software Pro/E to carry out three-dimensional designing, modeling, virtual assemble and motion simulation, and used structural mechanics analysis module Pro/Mechanical to carry out finite element analysis of key parts to optimize design of vertical hammer mill. In the designing process designer can easily modify the parameters, and directly observe the shape, location and movement of parts, which can greatly improve the design efficiency and level.
Numerical Simulation of the Influence of Temperature and Pressure in CVI of C/C Composite
Authors: Xu Peng , Liao Dun Ming , Zhou Jian Xin , Pang Sheng Yong
Published: April 2012

A reduced model was used to simulate the CVI process from methane. The scale of the preform was 120mm in diameter and 90mm in height. A random pore model was used to describe the evolution of pores in preform. Parameters such as temperatures and pressures were studied to research the deposition process. Effects of these two parameters are similar but have different impact mechanisms according to the analysis of results. Temperature impacts the reaction rate to improve the efficiency of deposition, while pressure impacts the concentrations of all hydrocarbon and then improves the total amount of carbon which also results in an increase of density.
The Experimental Research on the Effect of Age on Bond Behavior between Deformed Bar and Shale Ceramic Concrete
Authors: Wu Yan , Yu Jie , Wang Yan
Published: April 2012

In this paper, the effect of age on bond behavior between deformed bar and shale ceramic concrete was analyzed by four groups of pull-out tests with different age. And three reinforced concrete pull-out tests used for comparative analysis were prepared at the same time. We obtained a series of experimental data and based on these data a more accurate formula was summed up. This conclusion is important for further study on bonding properties of ceramic concrete and has a high value in guiding the actual construction.