bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Optical Basicity for Estimation of Viscosity of SiO2-CaO-MgO-Al2O3 System
Authors: Hong Chuan , Gao Yun Ming , Wang Shao Bo
Published: October 2014

A viscosity model based on NPL model with the corrected optical basicity is proposed for quaternary SiO2-CaO-MgO-Al2O3 slag system in the present work. The modified Arrhenius type of equation for temperature dependence of slag viscosity is employed. By means of fitting measured viscosity values for slags with basicity from 0.4 to 1.0 and temperature from 1593 to 1803 K, model parameters are optimized against values of optical basicity, which represents both the structure of molten slags and cationic effects. The relationship between model parameters and optical basicity, which is different from NPL model, is obtained. The present model is applied to estimate viscosity values of slag in SiO2-CaO-MgO-Al2O3 system. The comparison between estimated and measured values shows good agreement with a mean deviation of 12%. It proves fully that the present model can express the temperature dependence and composition dependence of viscosity.
Study on the Control Strategy of Polydimethylsiloxanols Continuous Production System in One-Step Synthesis
Authors: Jin Hai , Kong Wei Huan , Du Peng Ying , Jiang Hao , Luo Xiao Ping
Published: October 2014

According to the reaction principle of polydimethylsiloxanols produced by one-Step synthesis, the mathematical model is fitted by analyzing the result of test. This is a complex system with nonlinear time-Varying coupling characteristics, considering the requirements of dynamic and static performance indicators ,easily controlled features and simple structure, the combine control strategy of conventional PID and Fuzzy PID is used. The results show that the control precision of conversion rate is high and the robustness and adaptive ability of the system are both improved. This lays theoretical foundation to produce the polydimethylsiloxanols continuously in large scale in the future.
Environmental Factors on Aging of Nitrile Butadiene Rubber (NBR) - A Review
Authors: Tang Qing Yun , Zhang Wei Fang
Published: October 2014

Nitrile butadiene rubber (NBR) comes into widespread applications due to the excellent performances, but it is susceptible to aging during its storage and usage periods. This paper surveys the external factors that act on the aging process of NBR. The aging of NBR in liquid environment, and non-liquid environment such as thermo-oxidative aging, ozone aging, stress aging and radiation aging, are considered. The emphasis of present works is test of physical and mechanical properties of NBR, and the micro analysis should gain special attention. One direction of future research on NBR aging is the coupling effects of various factors included in this paper.
Impact of Thickness on Rubber Aging Life
Authors: Cai Yi Kun , Ma Xiao Bing , Wang Hao , Zhao Yu
Published: October 2014

Rubber products of different thickness have a significant difference of aging degree in mechanical properties due to varied environmental impact from surface to center. Previous study of performance degradation and life prediction methods did not pay enough attention to this problem. In this paper, a quantitative analysis is conducted, and a relationship between properties of different depth (given by a 40 years indoor natural aging experiment) and material overall properties is built to observe mechanical properties changing and evaluate aging life of different thickness of rubber. The result shows an obvious difference in mechanical properties and aging life, which seems should be considered when conduct an aging experiment and life evaluation.
The Technical Reconstruction for the Tantalum-Niobium Tailing Mine in Jiangxi Province
Authors: Liu Yue Long , Liu Jia
Published: October 2014

Yichunhas the largest rare-metal reserves in China, the explored reserve of lepidolite accounts for 31% in China and 12% in the world, it reserves of Rb and Cs are also the largest in China. The mining process of tantalum-niobium in Yichun and the technical reconstruction for the tantalum-niobium tailing mine is investigated.
The Application of the Fly Ash Excitated Grinding Materials
Authors: Hang Mei Yan , Zhang Li Ming , Su Jing , Zhang Ping
Published: October 2014

The fly ash of non grade with low activity can not be directly used in the cement concrete. After a lot of tests, several kinds of fly ash grinding excitation materials were chosen to be ground together with fly ash of non-grade and low activity. The studies show that three kinds of fly ash grinding excitation materials A, B, C can not only decrease the water demand ratio but also increase the activity index of the polished ash as well. All other indexes meet the requirements of technical specification standards for fly ash gradeI. Based on the effect of excitation activity and economic benefits, the fly ash grinding material B was chosen as the main active materials for the power plant to make excitation ash,the fly ash composite materials can be widely used in cement concrete with high activity index and great benefits, and the problems for the application of the long-term piled fly ash can also be solved .
The Research of the Absorption and Angle Characteristics of Honeycomb Hexagon Phase Modulation Membrane
Authors: Yi Ying Ying , Hao Wan Jun , Zhao Hui Chao , Dong Yi Feng , Yu Xin Dan
Published: October 2014

According to the honeycomb hexagonal phase modulation membrane, this paper designed and prepared λ/4 electromagnetic wave absorber. Studies have shown that the honeycomb hexagonal phase modulation membrane structure can realize the absorber width. Experiments have shown that 65% of bandwidth below-10 dB was achieved under following conditions: line length a = 4 cm, line weight b = 6 mm. For line length a = 4 cm, line weight b = 6 mm, the angle characteristics of phase modulation membrane was studied. The study of angle characteristics have shown that, absorption peak moved backward with the angles increasing. This new composite materials can be used for electromagnetic interference protection for WLAN and indoor electromagnetic radiation pollution control.
Property Comparation of Ti-Based and Cr-Based PVD Nitride Coatings
Authors: Liu Ai Hua
Published: October 2014

In this paper, the properties of TiN, AlTiN, CrN and CrAlN coatings were studied and compared, include physical and mechanical properties and micro morphology. The result showed with addition of Al, ternary AlTiN and CrAlN coatings showed dense structure and high hardness compared with TiN and CrN coatings. Adhesion strength of the Cr-based coatings was obviously higher than Ti-based coatings, but the roughness of Cr-based coatings was less than Ti-based coatings. Concerning microstructures of the coating, better ductile and dense are the remarkable character of the AlTiN and CrAlN coatings because of the disappearation of the “drop-lets” and columnar crystals.
Resin Material Used in Methyl Acrylate Hydrolysis Reaction
Authors: Li Ya Ping , Huo Quan , Zuo Cun Cun , Cao Sha Sha , Wang Er Qiang
Published: October 2014

In this work, the ion exchange resin catalyst named D072 were used in the hydrolysis of a methyl acrylate to acrylic acid and methanol firstlyand chemical equilibrium would be achieved during the process of the reversible reaction system. The influences of parameters such as dosage of catalyst, initial reactants molar ratio and reaction temperature were investigated. Meanwhile, the reusability of cation-exchange resin was studied, and no phenomenon of deactivation was found with using of reused catalyst. Moreover, the experimental data were analyzed by the pseudo-homogeneous (PH) model and the hydrolysis dynamics equation of methyl acrylate was obtained and found that the activation energy of the reaction was 118.37 KJ/mol in the presence of D072. Based on the result, high energy would be needed to the hydrolysis of methyl acrylate in using D072 resin as catalyst.
Experimental Investigation on LGJ-400/50 ACSR Surface Erosion Characteristics in Wind Sand Environment
Authors: Hua Guang Ru , Lin Ying Chao , Guo Yang Yang , Wang Yu Chen
Published: October 2014

Surface state of transmission line is an important factor to the corona characteristics. Therefore, this paper using surface roughness as the experimental parameters, using Aluminum Conductor Steel Reinforced cable LGJ-400/50 as the experimental materials in wind sand environment, studied the effect of sand particles on the surface of LGJ-400/50 Aluminum Conductor Steel Reinforced cable though the wind tunnel experiment. According to the experimental results a line chart about roughness changing along with the erosion time is obtained. By using Matlab least square fitting function make the line chart into a curve so that trends can be clearly reflected. The results show that: (1) the curve can be divided into two parts: the fast rising stage and the stable stage, the stable stage is related to the formation of oxide layer; (2) when the attack angle is 30 ° surface erosion is the most serious and changes of surface roughness have a maximum value.
Effect of Nano TiO2 Coating on Electrochemical Performance of the Li1.2Mn0.6Ni0.2O2 Cathode Materials
Authors: LI Jian Chen , Pang Sheng Li , Shen Xiang Qian , Xi Xiao Ming , Liao Da Qian
Published: October 2014

In this paper, a Li-rich cathode material Li1.2Mn0.6Ni0.2O2is modified by the nanoscale TiO2coating using a simple and controllable hydrolyzation method. The effect of nanoscale TiO2coating on the bulk structure, surface morphology and electrochemical performance are characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and electrochemical techniques, respectively. The results show that the nanosize TiO2can be well coated on the surface of the cathode material. The coating layers have no influence on the bulk structure of the cathode material, while they can improve the initial discharge capacity, columbic efficiency and cycling performance.
Effect of Annealing Temperature on Structural and Optical Properties of Ceria Nano Particles
Authors: Hong Chu Chuan , Qian Zheng Hong , Li Jian Ping , Peng Ying Zi
Published: October 2014

Pure and single-phase ceria particles were synthesized by an anodic electrochemical method followed by annealing at 500-900°C for 2h. Many characterization methods have been used to study the ceria nanostructures and electronic structures, including X-ray diffraction, transition electron microscopy and UV-vis spectrophotometer. The average crystallite size was estimated to be the scale of nanometers. While annealing at a low temperature, ceria particles are a little agglomeration and are termed as mesocrystal. It is observed to increase the crystallite size in addition to increase the crystalliminty of the nanoparticles while increasing the annealing temperature. The absorption spectra show that the ceria nanoparticles have direct and indirect band gap structures. There is a red shift of the absorption peak for the particles after annealing. Both the direct and indirect band gap energies are found to decrease with the annealing temperature.
Optical Emission Spectroscopy Measurement of Ar\H2\CH4 RF Plasma for Nano-Crystal Diamond Film Deposition
Authors: Shi Yan Chao , Zhang Qin Jian , Li Jia Jun , Chen Guang Chao
Published: October 2014

Ar\H2\CH4 gas mixture was utilized to grow nanocrystal diamond films in a RF plasma enhanced CVD system. CH4\ H2 ratios were changed to study the effect of plasma radicals on the deposit, in which optical emission spectroscopy (OES) was applied to analyze the plasma radicals. It was found that Hα, Hβ, Hγ, CH, C2 were the main radicals in the plasma. Among them, the CH intensity of OES was usually quite strong and increased sharply when the ratio of CH4/H2 was greater than 3%. The intensity of C2 was weak and basically unchanged with the addition of methane. This study can provide a new possible technical application for depositing NCD films.
Analysis on Measuring Circuit of Pressure Difference Sensor with Magnetic Fluid
Authors: Hao Rui Can , Liu Hua Gang , Gong Wen , Ma Jin Ru
Published: October 2014

Due to many sensing properties, magnetic fluid is used in a novel application--sensor. The measuring circuit is an important part for a sensor. Designing and calculation of the measuring circuit for pressure difference sensor with magnetic fluid were done. The power frequency and the input voltage are the two important factors for the measuring circuit. By experiments and calculations, the power frequency range is 20-70kHz and the input voltage for the circuit is 8V. The measuring circuit for inductive sensors was selected and calculated by analyzing measuring circuit for sensor.
Simulation on Electrical Conductivity of CNTs/PE Composites
Authors: Li Chang Ming , Li Chun Yang , Zhang Cheng Cheng , Fan Ming Yue , Cheng Yan Li , Han Bao Zhong
Published: October 2014

In order to investigate the electrical conductivity of carbon nanotubes (CNTs)/polyethylene (PE) composites, the relationship curves between the external electrical filed strength and the electrical conductivity of CNTs/PE composites with different microstructures were generated based on numerical simulation. The simulation models of CNTs/PE composites were designed through changing the content, aspect ratio and orientation degree of CNTs. After DC electrical field is applied between top and bottom surfaces of the composites, the distribution of electrical current density was calculated based on the finite element method by using the COMSOL simulating software, and then the electrical conductivity is obtained. Research results indicated the electrical conductivity of the composites increases significantly with the increase of aspect ratio of CNTs at the same CNT content and electrical field strength. As the orientation degree of CNTs along the applied electrical field increases, the electrical conductivity of the composites obviously increases. It can therefore be concluded that the changing of microstructures of CNTs/PE composites is effective to control the electrical conductivity of the composites.
The Research on the Piezoelectric and Dielectric Properties of Bi0.5(Nak)0.5-BaTiO3 Lead-Free Ceramics
Authors: Guo Jian Yong , Zhou Tao Sheng , Liao Ji Hong
Published: October 2014

The Bi0.5(Na1-xKx)0.5-yBaTiO3(BNK-BT) lead-free ceramics have been prepared by the solild reactive sintering method. XRD patterns show the BNK-BT ceramics had a perovskite structure. Piezoelectric and dielectric properties of the ceramics also have been studied. The results show that the samples had the best piezoelectric and dielectric properties when x=0.20, y=0.10. And the maximum of d33is 149 pC/N, while the relative dielectric constant is 1087.
Synthesis and Characterization of Optically Active Poly(N-Acryloyl-L-alanine) in Ionic Lliquids
Authors: Fan Rui , Yao Jin Shui
Published: October 2014

The chiral monomer,N-acryloyl-L alanine, was synthesized by condensation reaction between acryloyl chloride and L-alanine using ethyl acetate and water as two-phase solvents, tetrabutyl ammonium bromide as phase transfer catalyst and ethyl acetate as the extraction solvent.And then, poly (N-acryloyl-L-alanine) was successfully prepared by free radical polymerization of above synthesized monomer using 2,2'-Azobis (2-methylpropionitrile) AIBN as initiator in ionic liquids. Their structures were characterized by1HNMR and IR. Optically activities were tested with Rotary Spectrometer. Melting point and glass transition temperature were tested with DSC. The molecular weight of the polymer was characterized with GPC.
Improvement of Pulsed Holographic Recording Characteristics of Polyvinyl Alcohol/Acrylamide Green-Sensitive Photopolymer
Authors: Chen Gang , Zhu Jian Hua , Luo Zhen Xiong , Zhao Yu , Li Ze Ren
Published: October 2014

Coherent pre-illumination technique is proposed to improve the pulsed holographic recording characteristics of polyvinyl alcohol (PVA) /acrylamide green-sensitive photopolymer. By optimizing the pre-illumination parameters such as pre-illumination energy density and pre-illumination delay time, the photosensitivity and diffraction efficiency of photopolymer under pulsed holographic recording are improved effectively. For the coherent pre-illumination energy density of 2mJ/cm2, total pre-illumination energy of 50mJ/cm2, the diffraction efficiency of 85% can be obtained with holographic exposure of 35mJ/cm2. For the coherent pre-illumination delay time of 20seconds, the diffraction efficiency of 60% is obtained with holographic exposure of 17.5mJ/cm2. The photosensitivity is successfully improved about 8 times compared with other reported results, it has good application prospects in the measurements of high-speed transient processes.
Synthesis and Optical/Electrochemical Properties of Conjugated Polymers with Diphenyl and Thiophene in Main Chain
Authors: Wang Qing Xiu , Duan Li Jie , Qu Bo Yang , Wang Juan , Liu Fu De
Published: October 2014

Two thiophene derivatives 4,4'-di (thiophen-2-yl) biphenyl and 4,4'-di (thiophen-2-yl) -2-nitrobiphenyl ,which were used as monomers for preparing poly (4,4'-di (thiophen-2-yl) biphenyl) (DPBT) and poly (4,4'-di (thiophen-2-yl)-2-nitrobiphenyl) (DPNT) by ferric chloride oxidation polymerization, were synthesized via Suzuki reaction with 4,4'-dibromobiphenyl as the raw material. UV-vis absorption spectra, fluorescence spectra, photoluminescence spectra and electrochemical properties of the polymers were recorded and used for calculating the band-gap (Eg), HOMO orbital energy (EHOMO) and LUMO orbital energy (ELUMO) of the polymers. The calculation results indicated that attaching an electron-withdrawing group such as-NO2to the main chain can lower band-gap and increase the maximum absorption wavelength.
The Effect of Laser Focus Position on Laser Induced Plasma Characteristics
Authors: Lu Meng Ke , Zhao Shu Rui , Guan Kui Wen , Wang Yan Ling
Published: October 2014

Laser induced plasma is a relatively complex process which is closely related to many factors. In this paper, using a short pulse Nd:YAG laser and CCD photoelectric detection system, the variation of laser focus position effected by spectral intensity, the ratio of signal to background as well as the self-absorption of the plasma spectral lines with the standard spectra sample of aluminum for analysis samples was studied. Results show that: when the laser focus position is about 5mm under the surface of the sample, the relative intensity and the ratio of signal to background of the spectral lines are the strongest, and the spectral lines are sharp without obvious self-absorption.
Fabrication and Optical Properties of NiO-SiO2 Composite Photonic Crystals
Authors: Yan Gang Yin
Published: October 2014

NiO-SiO2 composite photonic crystals were fabricated by the self-assembly and the spin coating method. First, the SiO2 monodisperse colloidal spheres were fabricated by the Storber method and the opal structure was obtained by the vertical deposition method. After spin coating and sintering, the electrochromic material NiO was infiltrated in the opal template. The obtained NiO-SiO2 composite photonic crystal was characterized by X-ray diffraction (XRD), and the morphologies of SiO2 opals and the composite structures were characterized by SEM. The reflection spectra were measured and revealed that the periodic arrays exhibit a photonic band gap in the (111) direction.
Adsorption of Lead on the LDO Based on Reconstruction of LDH
Authors: Xie Xiang Li , Zhang Jie , Wang Lin Jiang
Published: October 2014

The Mg-Al layered double hydroxide (LDH) with carbonate interaction was synthesized by the urea method under hydrothermal conditions and layered double oxide (LDO) was prepared by calcination of LDH. The LDO was used as adsorbents for the removal of lead from aqueous solutions. The X-ray diffraction patterns of the LDO demonstrate that the adsorption is significantly enhanced by reconstruction of its original layered structure in the presence of lead with the memory effect. The process involved a fast adsorption within three hours, followed by slower, more gradual and stable adsorption. The adsorption capability for lead is 6.26 mg/g. The results indicate that the calcined Mg-Al layered double hydroxide is an efficient adsorbent for the treatment of waste water with heavy metal ions.
Design and Development of Flame Retardance Chef Coats Fabric of Polysulfonamide
Authors: Zhang Jun Ying , Ma Jun , Li Xiang Hong , Liu Hai Wen
Published: October 2014

The purpose of this paper is the development of flame retardant chef coats fabric. The main properties of polysulfonamide fiber are described , the research and development of the product processing of polysulfonamide /Aramid 1313 blended yarn and the union fabric with it and cotton yarn are explored. The technology problems of spinning and weaving are solved. The mechanical property , comfort property and flame retardance of the fabric of polysulfonamide /Aramid 1313 blended yarn and cotton yarn are qualified .The product can be used for high grade chef coats fabric.
Fuzzy Logic Applications in Gears Manufacturing
Authors: Turc Cristian Gheorghe , Banciu Felicia , Belgiu George
Published: October 2014

The experts of industrial design field consider the product early design stage as one of the most important stage of the design process, because it influences all stages of the product life cycle. One of the capital questions for manufacturing or design engineering people is how simple or elaborated work piece to use for a given part, in a specific set of production conditions. The optimization problem consists of the choosing of the right work piece for the current production conditions. In many cases this problem is solved empirically, based on the experience of the manufacturer. This approach leads to results that are situated more or less close to the optimum for the technical and economical point of view. Fuzzy logic is a method that is used in system control and analysis design, because it shortens the time for engineering development and sometimes, in the case of highly complex systems, is the only way to solve the problem. For the parts manufacturing, the main idea of the algorithm is to formalize the knowledge regarding production volume, loading conditions and other factors, using fuzzy sets and then to take the work piece choosing decision through the inference rules that are specified to fuzzy logic methodology. The described fuzzy logic algorithm allows a rapid, argued choosing of the work piece type in the production. The paper describes the method implementation for the manufacturing of gears, including the description of the software results and their interpretation.
Researches into the Stochastic Modelling of the Brake Shoes Stock Used in Railway Wagon Maintenance
Authors: Orhei Bercea Bianca Silvia , Lupescu Octavian , Bercea Lucian Dumitrel
Published: October 2014

The brake system maintenance of railway wagons consists, amongst other matters, brake shoe replacement whose wear in time exceeds the maximum allowable limit. Their absence in stock leads to the maintenance process stagnation. This causes additional costs of procurement and very high costs because of shortage. Thus, the main objective in control of the brake shoe stocks, in a company carrying out maintenance activities of railway wagons is that of determining the quantity ordered and the interval between orders. Their optimal values will be reached when storage costs, expressed by the cost function (the total mean value of the costs) are minimal, leading to a normal unfolding of the corrective maintenance activities. For the management of the spare parts stocks to be applied various methods, depending on the certainty or uncertainty knowledge of the level demand; of their delivery time and of their supply costs. For avoiding increasing penalty costs due to lack in stock the authors propose, after the estimation of the relative variability of demand for these spare parts, the stochastic modelling utilisation, the demand and delivery time being discrete random variables (depending on season, type and random rhythmicity of the falls), known being the request repartitions of the brake shoes on the basis of statistical records. The research results led to the determination of the value necessary to brake shoes stock so that, the total losses of the company in which carried out the maintenance activities to be minimised, and to establish the range of cost in which is allowed the acquisition of a such spare part when she is missing from the stock.
Growth of AlN by Reactive Gas Injection of Nitrogen in an AlMg Matrix
Authors: Peter Ildiko , Florea Raluca Maria , Bălţătescu Oana , Carcea Ioan
Published: October 2014

The primary objective of the present research was to provide a fundamental understanding of the processing science necessary to fabricate the Aluminum Nitride (AIN) reinforced Aluminum-Magnesium (AIMg) composites via Reactive Gas (N2) Injection in the AIMg alloy melt. Aluminum nitride (AlN) matrix composites were prepared by a novel approach. It was possible to produce a considerable amount of AIN particles in the AI alloy matrix at a reaction temperature as low as 900 °C utilizing the in-situ nitration reaction process developed in the present study. The volume fraction of AIN increases almost linearly with increasing the magnesium (Mg) content in the alloy and the reaction time. The shapes of AIN particles were found to have different forms, whose sizes were in the range from submicron to a few microns. From the present study, it is concluded that the new innovative in-situ nitridation process developed in the present study can be successfully applied for processing of high strength AIMg/AIN composites. For particles and composite structure characterization some methods were used, including: scanning microscopy, quantitative analysis of selected composite regions and XRD analyses. Composite structure and reinforcement distribution was compared with use of quantitative analysis. Morphology and diffraction pattern of aluminum nitride particles was shown. Typical structure of studied composites with microanalysis results was indicated. Aluminum nitride dispersion change was represented.
Impact Resistance of “Liquid Wood”
Authors: Nedelcu Dumitru , Plavanescu Simona , Puiu Elena
Published: October 2014

The main substances with an important effect over any company development are the materials which require simple or complex manufacturing processes. In the near future the using of recyclable materials will become an extremely important factor in all of activity fields. Therefore, liquid wood, due to its biodegradability and mechanical properties superior to other plastics, could replace some plastic materials soon. In case of arboform the granules made from: lignocellulosic fibers (combination of cellulose, lignin and wood polyoses); natural Polymers: lignin, polyester; natural resins/waxes: aliphatic and aromatic ketones, alcohols, carbonic acids, lactones and polycycles in monomeric, oligomeric and polymeric form. In case of arbofill it made from petrochemical polymers like polypropylene or polyethylene, reinforced with natural fibres like hemp, flax or wood. The arboblend contains different biopolymers like e.g. polyhydroxialkanoate, polyester, ingeo TM, lignin, starch, cellulose, organic additives, natural resins or waxes and natural reinforcing fibers, [. Because the injection process of arboform L, V3 Nature was very difficult this material was reinforced with 5% aramid fibers. The properties of liquid wood are very important to be known take into account the possibility to find some plastic materials for replacing. Therefore the paper presents some aspects of research concerning the impact resistance of these materials. For that was used the injection process to obtain the samples with six input parameters inside of experimental plan. Each factor had two level and was used the Taguchi methodology. The results obtained and the plastic materials that could be replaced are as follow: arbofill Fichte: (11-15) kJ/mp and it could be replace the PC GF 30, PPE GF 30, PEEK GF 30 (Poly Ether Ether Ketone Glass Filled), PEEK CF 30 (Poly Ether Ether Ketone Carbon Filled), PEI GF 30 (Poly Ether Imide); arboblend V2 Nature: (20-26) kJ/mp and it could be replace the PA 66 GF 30, PA 11 GF 30, PC GF 30, PP GF 30, PMMA, PPE GF 30, PEEK GF 30 (Poly Ether Ether Ketone Glass Filled), PEEK CF 30 (Poly Ether Ether Ketone Carbon Filled), PEI GF 30 (Poly Ether Imide) and arboform L, V3 Nature reinforced with aramid fibers: (8-14) kJ/mp and it could be replace the PC GF 30 (30% glass fiber), PVC, PPE GF 30, PEEK GF 30 (Poly Ether Ether Ketone Glass Filled), PEEK CF 30 (Poly Ether Ether Ketone Carbon Filled), PEI GF 30 (Poly Ether Imide).
Distribution Coefficient of Arsenic Durng Liquid-Phase Epitaxy Layer Growth of Phosphide-Arsenide of Gallium
Authors: Ciofu Iurie , Ciofu Andrei
Published: October 2014

It is crucial to know the distribution coefficients of chemical elements in melts. This is essential for obtaining a given composition and properties of epitaxial layers grown from the liquid phase, for determining the regimes of high purification of materials obtained by zone melting, for producing the desired gradient of distribution of alloying elements throughout the layers of construction materials treated by chemical-thermal methods, etc. This paper presents the results of computing the distribution coefficient of arsenic during the growth of layers of phosphide-arsenide of gallium from the liquid phase (molten gallium), saturated with phosphorus. We also obtain the dependencies between the distribution coefficient of arsenic, the temperature and the concentration of arsenic inside the gallium melt during the growth of epitaxial layers. As well a practical application of the results with a given gradient of concentration for the gallium arsenide layer is demonstrated.
Oxidation Resistance of Coating Obtained by Innovative Methods for Energy Boilers
Authors: Szczucka-Lasota Bożena , Majewski Wojciech
Published: October 2014

The material conception of manufacture nanocomposite coatings with high dispersion phases are presented. The structure surface was obtained by modified technology HVOF aand PMR with micro-jet cooling. The macro and microstructure of composition coatings after the high temperature corrosion test are presented. The oxidation resistance of coatings contain multilayer structure with high dispersion ceramic particles are obtained. The presented coatings use to basic protection to wear and corrosion condition or modified surface of multilayer coatings in the energy boiler.
Formation of Taylor Cone Shaped Asperities on Cylindrical Surfaces by Applying Electric Discharges in Pulse
Authors: Topala Pavel , Rusnac Vladislav , Guzgan Dorin
Published: October 2014

This paper presents the results of experimental research on Taylor cone shaped menisci formation on the surfaces of pieces by applying electric discharges in pulse. It examines the influence of energy stored in the capacitor and of pulse duration on their formation. The modification of piece surface micro-geometry aims to increase the capacity of absorption of radiation and of particle emission. It shows that the size of formed menisci depends on the energy regime of machining, on the gap size, on the duration of electric discharges in pulse and on thermal physical properties of the material used to execute the piece.
Contact Wear Studies over Idlers Sprayed with Ni Al Si Powder Using Atmospheric Plasma Spraying Method
Authors: Avram Petru , Istrate Bogdan , Imbrea Marius Stelian , Axinte Catalina , Paulin Constantin , Strugaru Sorin Iacob , Munteanu Corneliu
Published: October 2014

In military and mining industry are many machine elements – in our case idlers (for tanks, conveyors, and any others machineries which are using transmissions system which are subjected of coverage with a high wear rezistance powder. These machine elements (idlers) must have high wear proprieties, because the functionality of the entire transmissions systems depends on them. Also the maintenance costs are very high, that is why we proposed to studies how to improve the performances of this machine elements. Researches in surface engineering allow the obtaining of new systems of materials by coating the basic material surface with other material having superior high wear properties. In order to improve the machine elements durability, wear resistance, friction, we proposed to obtain a new system of materials using Atmospheric Plasma Spraying – with Sulzer 9MCE equipment. We have chosen the steel type 34CrNiMo6, MOCN class, STAS 691 - 880 as basic material and we coated it with NiAlSi powder. We made the samples and we tested them. The analysis has been made with Tribometre, which produces some data which link us to a high wear rezistance.The NiAlSi coating deposited on steel substrate is dense and very tought. The results showed that the new material has a better microstructure than the basic material and its physical and mechanical properties have been improved.
Microbiological Testing of Biodegradable MgCa Alloys for Use in Orthopedic Implants
Authors: Crimu Carmen , Stanciu Sergiu , Cristea Diana Pitul , Focșăneanu Sergiu Ciprian , Munteanu Corneliu , Earar Kamel
Published: October 2014

Implants based on titanium alloys, stainless steel and cobalt –chromium have been the primary biomaterials used for load bearing applications and they have been remarkably successful throughout time, but on the long term, there appear a series of inconveniences regarding these metallic implants. Thus, there have been cases of aseptic osteolysis around the implant, with pain and high degree of loosening of the prosthesis which constitutes a limitation of the long term benefits of metallic implants. Therefore, researchers have found new materials for implants, more competitive and efficient. These are materials that are biocompatible and biodegradable. These constitute a novel class of bioactive biomaterials which are expected to support the healing process of a diseased tissue and to degrade thereafter. Magnesium alloys attracted great attention as a new kind of degradable biomaterial. Mg is an essential mineral for human metabolism and its deficiency has been linked to various pathological conditions. The main advantages of Mg alloys are its superior mechanical and biocorrosive properties and its biocompatibility. Mg is a very light-weight metal with a lower density than that of biocompatible Ti alloys, which is closer to that of the human bone. In the present paper we shall focus on presenting some biological testing studies of several Mg alloys from the system Mg-Ca, with different percentages of Ca. Three methods have been use for this: determining the ph at different sample incubation times in culture environment; citotoxicity tests made in vitro which: evaluate the contact toxicity by putting the samples in the buckets of cellular culture plates; evaluate the cellular proliferation at the surface of the tested materials by fluorescence microscopy and deflection microscopy; evaluation of toxicity by testing the effect of the extraction liquid resulting from the incubation of the material with testing cell specific culture environment.
Comparative Study Concerning the Generation of some Circular Grooves by Radial Cold Rolling with Roller Tools and Cutting
Authors: Nitu Eduard Laurentiu , Iordache Daniela Monica , Iacomi Doina
Published: October 2014

This study is part of the concerns that the authors have had in recent years, representing an extension of a research project funded consisting in modelling representative cold rolling processes of profiles. This paper presents a comparative analysis of quality of the superficial layer of a circular profile (grooves) obtained by two different processes: radial rolling with two roller tools and turning with radial feed. Also, the two processes are compared from the viewpoint of economic efficiency. The materials used for the experiments are frequently used to obtain pieces with circular grooves: two types of cementation steel and two types of heat treatable steel. The characteristics of the superficial layer which describe its quality and which are comparatively analyzed in connection to the two processes are: roughness, microstructure and micro-hardness. The economic efficiency of the two processes was assessed by means of the costs implied and the productivity of processing. The interpretation of the results obtained enabled stressing the advantages to generate circular grooves by cold radial rolling from the point of view of the quality of the superficial layer of pieces, as well as the limits of the use of this process from the viewpoint of economic efficiency.
Fuzzy Failure Mode and Effect Analysis Application to Improve Laser Cutting Process
Authors: Belu Nadia , Rachieru Nicoleta , Anghel Daniel Constantin
Published: October 2014

Failure mode and effect analysis (FMEA) is one of the well-known techniques of quality management that is used for continuous improvement in product or process design. It is widely used in manufacturing industries in different stages of the product life cycle and is now increasingly finding use in the service industry. Even through this approach is simple but there are some limitations in obtaining a good estimate of the failure ratings. Thus, a new risk assessment system based on the fuzzy set theory and fuzzy rule base theory is proposed in this study to solve these problems that have arisen from conventional FMEA. Furthermore, an analysis is presented to demonstrate the traditional FMEA. We present of a parallel between the typical and the fuzzy computation of RPNs, in order to assess and rank risks associated to failure modes that could appear in the laser cutting process. This work can also serves as a failure prevention guide those who perform the laser cutting operation.
Determination of some Mechanical Characteristics of Wood Elements Improved with Composites Materials
Authors: Ianăşi Aurora Cătălina
Published: October 2014

Wood is a material of construction relatively inexpensive and easy to put into practice because of its lightness, reusability, simplicity in fabrication and environmental compatibility. However, its ability to lift load small compared to other building materials, it greatly limits the range of its use. Increasing the mechanical strength of wood elements used in construction is a goal that, once achieved, would expand the use of this material, with notable economic repercussions. The use of composite materials such as CFRP (carbon fiber reinforced plastic) as reinforcement for wood elements under bending loads like beams requires attention to the techniques of reinforcing for different layouts of CFRP elements. Each choice of reinforcing could potentially lead to different results. When the choice has been made, the next step is the selection of the most adequate CFRP elements. For this reason, selection of the reinforcement layout and material should be guided by an accurate analysis of the characteristics of the element to be reinforced in order to avoid ineffective interventions. The present paper is concerned with determination the performances of wood beams reinforced with CFRP composites by investigating their bending resistance and showing crushing damage in the bending region. All tested wood beamspresented in this paper were made from beech. The results for the un-reinforced beams are reported solely for the purpose of quantitatively evaluating the effectiveness of the interventions through a comparison with the results for CFRP strengthened beams. The technology of composite material reinforcement is based on using CFRP plates bonded with an epoxy resin on the wood beams. After bonding, the beams were tested to bending on a universal testing machine with a punctuated force placed at the middle of the beams. The results indicate that the behavior of reinforced beams with CFRP is totally different from that of un-reinforced one. During the performed tests, observations of the experimental loaddisplacement relationships showed that bending strength increased for wood beams reinforced with CFRP compared to those without CFRP reinforcement. Mechanical tests on the reinforced wood beams proved that CFRP materials produced flexural displacement and lifting increases of the beams that entitles us to say this kind of materials have improved the mechanical performances of tested wooden beams.
Experimental and Numerical Study of Heat Conditions during Diode Laser Gas Nitriding of Titanium Alloy
Authors: Lisiecki Aleksander
Published: October 2014

The heat conditions of laser gas nitriding (LGN) of titanium alloy Ti6Al4V by high power diode laser (HPDL) were investigated experimentally by non-contact pyrometric measurements and infrared camera analysis. Additionally direct observations of the weld pool shape were conducted by means of high speed digital camera. In the numerical study of the laser surface processing of titanium plate 3D model of heat flow was examined. Results of temperature values, distribution and temperature isotherms obtained from the 3D model were next applied in the two-dimensional stationary model of liquid metal flow in the weld pool. Experimental and numerical study showed that the temperatures of the weld pool during laser gas nitriding of the titanium alloy are significantly higher compared to these determined during laser melting in argon atmosphere at the same heat input. Additionally severe turbulences of liquid metal in the weld poll (Marangoni convection) were found during both experimental and numerical analysis.
An Optimization Study of Fluid Jet Flow in a Convergent Divergent Nozzle Geometry Used for the Cooling Systems of Machine Tools
Authors: Olaru Ionel
Published: October 2014

In this work it was performed a fluid mechanical study of cooling systems for metal cutting. In these machine tools are developed temperatures processing this should be minimized so as not to damage of the tool durability. Therefore should correlate pressures, temperatures and fluid flows used. Also the physical characteristics of fluids used are important for better cooling of the tool in the work area. All these factors lead to a better surface of machined area.
The Computer-Assisted Design Method of Staggered-Tooth Milling Cutter for Manufacturing of the Complex Helical Surfaces
Authors: Pleşu Gheorghe
Published: October 2014

The complex helical surfaces specific for the rotors of the helical compressors and of the screw pumps imply the production of a series of tools providing a high productivity.
The staggered-tooth milling cutter achieve these conditions but their design gives rise to difficult problems. In order to optimize their parameters and to facilitate their design, a package of programs has been created to select the constructive parameters of the tool, to calculate the profiles of the plates, the angles of the surface of section, the dimensions of the elements of attachment. In order to include all these elements in an efficient system of design, a series of regular calculations were applied for various parameters that were then included through the CAD software for design and documentation AutoCAD; at the same time, several applications of verification, construction and simulation of the functioning of the tool and of the cutting process were designed. The method applied in this case reduced to a considerable extent the time of design and it also improved the constructive solutions of the staggered-tooth milling cutter.
Considerations on Quality Parameters at Deformation and Splitting Process of Interior and Exterior Surfaces
Authors: Marin Alecsandru , Raveica Ionel Crinel
Published: October 2014

For going of the durability of the machining tools at the making of mild steel is proposed the andvanced straining, process which was applied in practice at the broaching the parts of holes valve rocker type. In this paper we propose to present some of specific aspects on the combined splinting and deforming process on internal and external sorfaces.
Loss of Aluminium during the Process of Ti-Al Alloy Melting in VIM Furnace
Authors: Oleksiak Beata , Blacha Leszek , Siwiec Grzegorz , Smalcerz Albert
Published: October 2014

Titanium alloys belong to a group of the most advanced metal materials with increasing applications observed in recent years, mainly in the aircraft, shipbuilding, automotive and chemical industries as well as in medicine. In the paper, results of the study on changes in aluminium content in binary Ti-Al alloys during smelting in the vacuum induction melting (VIM) furnace are presented. The experiments were performed at 5 Pa and 1000 Pa, 1973 K and 2023 K. The investigations were conducted for alloys containing up to 49%mass Al. Each experiment began with loading an alloy sample (about 1000 g) into the graphite crucible placed in the induction coil of the furnace. After closing the furnace chamber, the pre-specified vacuum was generated with the use of a pump system. When the pressure level was stabilised, the crucible was heated up to the required temperature and the metal bath was held for 600 sec. During each smelting experiment, metal samples were collected and subjected to a chemical analysis. The Al loss rate in each experiment was not higher than 21%; it increased with temperature and reduced pressure in the device. It is assumed that the observed loss of aluminium during smelting is the effect of evaporation. The obtained values of Al concentration in the investigated alloys ensured that the aluminium overall mass transfer coefficient in the process could be estimated. The values of overall mass transfer coefficient were 0.88 to 1.66×10-5 [m·s-1]. Lack of clear effects of the alloy composition on the analysed process rate proves that it is not controlled by mass transfer in the liquid phase.
Influence of the HPDL Surface Treatment of the X40CrMoV5-1 Tool Steel on Wear Resistance
Authors: Jonda Ewa , Lukaszkowicz Krzysztof
Published: October 2014

The paper presents the effect of alloying with WC and TaC powders on structure and mechanical properties of the X40CrMoV5-1 steel surface layer using the HPDL (High Power Diode Laser). The metallographic investigations on light microscope show that during alloying the X40CrMoV5-1 hot work tool steel with the WC and TaC powder the obtained run face is characteristic of the high roughness, multiple pores, irregularity, and flashes at the borders. The changes of the surface layers hardness formed as a result of alloying with ceramic powders containing carbides are accompanied with the increased tribological properties. The microstructure of the alloyed layers which were formed on the surface of the investigated hot work steel was examined using optical microscope. The tribological wear relationships using pin-on-disc test were specified for surface layers subject to laser treatment, determining the friction coefficient, and mass loss of the investigated surfaces.