bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis and Precaution of the Hard Spots in Die-Casting Parts of Aluminum Alloy
Authors: Zhang Xiao Yan , Guo Hui
Published: February 2011

The hard spots and the hard part defects within the base body in the die-casting parts of aluminum alloy were observed and analyzed by means of photon microscope, electronic probe, micro hardness tester and other experimental methods. The causes led to the hard spots were discussed. The measures and solutions to control the raw materials of the alloy and to improve the smelting process were put forward.
Effects of Superposed Field on Solidification Microstructure of Al-7wt%Si Alloy
Authors: Wang Zhi Hua , Zhu Ming , Xu Guang Ji
Published: February 2011

In this paper, the effect of superposition of rotating electromagnetic field and triangular pulse electric field on the microstructure of the cast Al-7wt％Si hypoeutectic alloy was investigated. The experimental results showed that solidification microstructure of Al-7wt％Si hypoeutectic alloy could be obviously improved from dendrites to nearly equiaxed grain with increasing the voltage of rotating electromagnetic field and α－Al dendrites were refined by superposed field. Moreover, refinement effects were further improved with increasing intensity of the superposed field.
Development of Basalt Fiber Reinforced Wood-Plastic Composite Materials
Authors: Chen Jin Xiang , Guan Su Jun , Zhang Shun Hua , Zheng Jing Jing , Xie Juan , Lu Yun
Published: February 2011

The relationship between properties of BF-WPC and the content of BF were studied, when wood-plastics composite (WPC) was reinforced by 12 mm and 3 mm short basalt fiber (SBF). The results showed that there may have some uneven distributions of SBF in WPC, when the content of 12 mm BF exceeded 30%. Restricted to the uneven distribution and the quantity of “end weak’’, it formed the close comprehensive property of BF-WPC by the length of 12mm and 3mm BF. The comprehensive property of BF-WPC has a maximum range of 15%-30% of the content of 12 mm BF. Compared to pure WPC, the tensile and bending strength of BF-WPC have improved. However, the reinforce effect of BF-WPC is different and is dependent on the index of each property. The BF-WPC plate can be developed with different properties and be a cost-effective material by choosing different length and content of BF.
Experimental Study on the Surface Micro-Geometrical Characteristics of Quenched Steel in Ultrasonic Assisted Turning
Authors: Jiao Feng , Liu Xiang , Zhao Chong Yang , Zhang Xiong
Published: February 2011

Compared with conventional turning, ultrasonic assisted turning demonstrates many advantages in turning of quenched steel. Surface micro-geometry is an important evaluation index of surface quality. In the paper, through the comparative experimental study of surface micro-geometrical characteristics in conventional and ultrasonic turning of 45 quenched steel, it can be finally obtained that the surface micro-geometrical characteristics in ultrasonic assisted turning are better than that of conventional turning, especially when adopting lower machining speed; ultrasonic assisted turning of quenched steel is much easier to realize “turning instead of grinding”.
The Effect of Speed Matching on the CMP Uniformity
Authors: Guo Zhi Xue , Zhai Jing , Zhang Hui , Li Qing Zhong
Published: February 2011

In the chemical mechanical polishing process, the relationship of relative motion of polishing pad and polishing head plays very important role for CMP quality. This paper established the mathematical model in order to investigate the relative motion of polishing pad and polishing head. It was found that the speed ratio of polishing pad and polishing head shows great influence on the CMP uniformity. And when the value of speed ratio of relative rotation approaches 1.23, the distribution of abrasives’ trajectories is close and uniform. Theoretically, the surface quality of workpiece is better.
Study on Creep Properties of SiCp/AZ61 Composites
Authors: Yan Hong , Huang Zhi Min
Published: February 2011

SiCp/AZ61 composites reinforced with SiC particles were fabricated by semi-solid stirring-melt casting technique. The creep properties of the composites have been studied by dynamic mechanical thermal analysis, micro-structural and XRD observation. The results show that the matrix grains were refined obviously at high temperature with SiC particles introducing and the creep properties of SiCp/AZ61 composites were improved comparing with AZ61 alloy. SiC particles were substituted for Mg17Al12 phase that was easily intenerated at high temperature on grain boundaries. The pinning of SiC particles prevents dislocation and slip of grain boundary at high temperature.
Study on Performances and its Structural Designing of the High-Speed CNC Lathe Epoxy Resin Concrete Bed
Authors: Qiao Xue Tao , Li Yun Sheng , Zhao Hui Ying , Wu Long , Zhao Ze Xiang
Published: February 2011

The epoxy resin concrete is one of high performance composite materials used to the basic parts of machine tool and measuring instruments. Based on the study of related technologies at home and abroad, technical route and manufacturing process on the development of machine tool bed have been proposed. The epoxy resin concrete material self developed and results of its performances testing are introduced, and they are contrasted with cast iron material. The high-speed CNC lathe was taken as example which characteristic of the epoxy resin concrete bed structural design has been explained in this paper. The cast iron bed and epoxy resin concrete bed of the high-speed CNC lathe has respectively been analyzed and contrasted by finite element method. At last, the performances of epoxy resin concrete bed exceeding to cast iron bed have been educed.
Reliability Analysis for Structure System with the Local Dented Plate
Authors: An Hai , An Wei Guang , Liu Ming
Published: February 2011

In this paper, the influence of the local dented plate on ultimate strength is analyzed, and reliability calculation and sensitivity analysis expressions of the plate element with local dents are also proposed. For the structure system consisting of local dented plate elements, reliability analysis is developed, the calculation method of the global reliability index and sensitivity expressions of the reliability index are proposed. Finally, taking a numerical example of a cabin section of ship structure compares and contrasts reliability analysis of the structure system with the local dented plate with that of the system without the local dents. The method proposed in this paper provides a reference for the maintenance and renewal of structure system in use.
Process Calculation of Producing Stainless Steel Crude Melts by the Chromium Ore Smelting Reduction in a Converter
Authors: Liu Yan , Jiang Mao Fa , Wang De Yong
Published: February 2011

The process calculation of producing stainless steel crude melts by smelting reduction in a 150 t converter is carried out for the first time by use of the empirical data and calculation method of refining plain carbon steel in a converter, according to the blowing conditions of 185 t smelting reduction converter of No.4 steelmaking shop in Chiba Works of JFE Steel. Using the self-programming procedure for the processing calculation, the proper coke quantity and a complete set of calculation data for the process of smelting reduction in a converter are obtained, including the batch calculation, the material balance and heat balance calculations. The calculation results show that the increase of PCR can decrease the quantity of coke and actual oxygen consumption considerably, and improve the thermal efficiency of smelting reduction converter. For producing 18 wt% Cr stainless steel crude melts, comparing with the process of electric arc furnace, the process of smelting reduction in a converter can reduce the production cost greatly. The use of the recycled metal containing chromium can shorten blowing time and improve the yield of chromium.
Three Dimensions Construction Model and Finite Element Analysis of Hydraulic Support and Relevant Model
Authors: Liu Hong Yu
Published: February 2011

Hydraulic support is an important equipment of coal mine production. Its design and manufacture level affects the safe production and economic benefits of coal mine directly. This paper took ZT6500/19.5/34 hydraulic support as an example. First, three dimensions solid models of the type simplified hydraulic support prototype and its 1:5 model were constructed by three dimensions construction model software SolidWorks. Then, three dimensions solid models were led in ANSYS software. Finally, the strength test of the type hydraulic support prototype and its 1:5 model were proceeded under base torsion working condition by ANSYS software. The relevant total displacement distribution rule and equivalent stress distribution rule of the type simplified hydraulic support prototype and its 1:5 model were found. The proportion relation of total displacement and equivalent stress between the type simplified hydraulic support prototype and its 1:5 model were confirmed. This provides an effective way of design and research hydraulic support.
Study of TI64 Vibration Laser Metal Deposition Process
Authors: Chen Xue Yong , Sparks Todd , Ruan Jian Zhong , Liou Frank
Published: February 2011

This paper presents the usage of vibration in laser direct deposition of Ti64. The vibration is used to refine the crystalline structure of the deposition. The vibration device vibrates in the laser deposition system along the Z axis. A design of experiments approach is applied in studying the effect of vibration on the deposited material. Vibration during deposition led to grain refinement and an increase in microhardness over that of samples from no-vibration. Also, vibration frequency is a significant factor. From the experiment results, it is found that a vibration frequency greater than 20Hz is desirable.
In situ Synthesis of Ceramic Phase Reinforced Fe-Based Alloy Surface Coating by PTA
Authors: Zong Lin , Liu Zheng Jun
Published: February 2011

The in-situ ceramic phases reinforced Fe-based surface coating had been produced by prepared high-carbon ferrochromium, ferrovanadium and graphite power on 20g steel through plasma transferred arc weld-surfacing process(PTA). The microstructure and properties were investigated by means of optical microscopy(op), scanning electron microscopy(SEM), X-ray diffraction(XRD) and microhardness meter. The results showed that the substrate and the coating formed good metallurgical bonding.The microstructure of coating consists of primary M7C3 carbide and eutectic structures[M+γ′+M7C3+VC]. The primary hexagonal (Fe,Cr,V)7C3 with larger size evenly distributed in coating and the fine VC particles were globular shape. The microhardness appeared reasonable distribution from substrate to the top ,which ensured that the materials had good abrasive wear resistance.
The Design and Analysis of Nozzle
Authors: Yu Jin Li , Chen Zai Liang , Zhang Xin , Gao Hui
Published: February 2011

Nozzle is an important component of the spray equipment, the thesis using the theoretical knowledge of fluid to calculate the nozzle’s size to design the nozzle, and also using the stress analysis module of the ANSYS software to analyze the stress to choose the optimal nozzle structure.
The Study on the Precipitation Behavior of the Second Phase Particles for As-Hot Rolled Dual-Phase Nb-Bearing Steel
Authors: Mei Zhang Hong , Feng Qiao Li
Published: February 2011

The precipitation behavior of the second phase particles was observed and studied by a carbon extraction replica technique used transmission electron microscopy (TEM) for Nb-bearing dual-phase steel. It is found that there are more second phase particles on the surface than that of in the center of sample. The mainly smaller particle which sizes of is below 20nm show the shape of spherical and ellipse. The sizes of larger particles are range of 20nm~40nm and the shape of them present rectangle or ellipse. The particles are dispersed on the matrix and the particle boundary is clear. The precipitate composition of particles are all Nb(C、N) examined by energy dispersive X-ray (EDX). The results of microstructure shows that the second phase particles pinned on grain boundary not only can inhibited the grain growth, but also the grain can be fined during the heating and cooling course.
Microstructure and Phase Composition of Iridium Coating on Molybdenum after Heat Treatment at 1400°C
Authors: Wu Wang Ping , Chen Zhao Feng , Lin Xin
Published: February 2011

Iridium (Ir) could be taken as high temperature protective coating for the refractory metals. Ir coating was deposited on the surface of molybdenum (Mo) substrate by double glow plasma. Thermal stability of the coating was investigated at 1400°C for 90 min, while Ar gas was inputted to hold the vacuum pressure. The microstructure of the surface and interface of the Ir coating were observed by SEM and TEM. The phase transition of the coating was determined by X-ray diffraction. Many micropores and microbubbles appeared in the surface of the as-heat treated coating. The interfacial reaction between the Mo substrate and Ir coating occurred during heat treatment, and Ir21.5Mo8.5 phase was formed at 1400°C. The experimental results indicated that the integrity of the Ir coating was not degraded after heat treatment.
Influence of Different Wave-Lengths Artificial Light on Surface Discoloration of Dyed Veneer
Authors: Shao Ling Min , Guo Hong Wu , Li Li , Liu Ya Lan , Liu Yi
Published: February 2011

Dyed Wood is rapidly degraded by short-wavelength UV radiation, and its degree of discoloration correlate well with the wave length. In the paper we test this hypothesis and analyze chemical change of dyed wood surface affected by UV radiation. So that it will be beneficial for further study on synthesis of photo stabilizer. In this research, dyed veneers are irradiated by artificial light using an ultraviolet accelerated weathering device including 5 different wavelengths (UV to visible). CIE (1976) L*a*b* color measuring system is applied to describe the photo-induced discoloration process of dyed veneer. The reflection curves of spectrum and K-M difference spectra show the diverse change of light absorption and reflection. The results reveal that, samples color is great influenced by 313nm and 340nm UV light, the color stability of dye stuffs is rapidly decreased while stimulated by 254nm UV light. The fastness of dyed veneer has a positive relationship with dye stuffs, Acid Red GR dyed veneer just suffer slight yellowing due to the stability of dye, while Acid Blue V dyed veneer fade obviously and get a tendency of reddish.
Inheriting of Traditional Culture in Design
Authors: Sun Xu Fang
Published: February 2011

A few problems, which appear in current Chinese developing design field, will be focus on in this article. The relationship between the traditional culture, inheriting of the culture and industrial design will be analyzed by the example of different country traditional culture embedded with different design. And, some characteristic of Chinese traditional culture has also been discussed. The relation will be clear on thinking to "person". The cultural inheriting will be embodying in design, realizing tradition and culture on the connotation.
Laser Cladding In Situ Tungsten Carbide Reinforced Ferrous Matrix Surface Composites
Authors: Chen Ying Ying , Li Wen Ge
Published: February 2011

Tungsten carbide cermets coating on carbon steel were fabricated by laser clad cooperation combustion synthesis method. The microstructure, phase, element distribution and microhardness have been analyzed with the aid of SEM, XRD, EDS, EPMA and microhardness-tester. It is shown that the coating consisted of WC, CW3, W2C, WCx, and FeNi3. The results of hardness measurement showed that the hardness was superior to substrate. Analyze the effect of different laser power and different laser scanning speed on the quality of the laser cladding surface, the surface quality gets better with the increasing of the laser power, and gets better with the reducing of the scanning speed.
Effect of Saccharin Addition on the Electrodeposition of Nickel from a Watts-Type Electrolyte
Authors: Li Yan Wei , Huang Xiao Xi , Yao Jin Huan , Deng Xing Shen
Published: February 2011

The influence of saccharin addition on cathodic polarization, cathodic current efficiency, hardness, surface morphology, and internal stress of nickel electrodeposition from a Watts-type plating bath was studied in this work. The results show that the addition of saccharin may enhance the cathodic polarization, modify the surface morphology, increase the hardness, and decrease the tensile stress. In particular, when the concentration of saccharin is 0.4 g/L, the surface of nickel deposition is smoothest. When the concentration of saccharin is 0.05 g/L, the hardness of nickel deposition is highest.
Preparation of ZrTiN Hard Coating and its Performance
Authors: Yan Pei , Deng Jian Xin , Chen Zhen , Lian Yun Song , Zhao Jun , Ai Xing
Published: February 2011

ZrTiN hard coatings were deposited by multi-arc ion plating on tungsten carbide substrates, using separated Ti and Zr targets in nitrogen and argon atmosphere, combined with ion bombardment of samples surface. The films exhibited a dense and fine grained structure with no columnar growth structure. ZrTiN coatings deposited reveal a (111) preferred crystal orientation. For the coatings, solid solutions were formed. The coatings possessed a higher microhardness value (approx. 2700 Hv0.05) than their binary counterparts. The increased microhardness was probably due to a solid solution strengthening mechanism while depositing. The thickness of the coatings were between 2.0 and 2.3 μm. The adhesive strength of the coating-substrate system was up to more than 70N.
Effect of Equal Channel Angular Pressing on Microstructure and Dislocation Strengthening of 3003Al Ingot
Authors: Song Tao , Xu Xiao Jing , Fan Zhen , Luo Yong , Wang Bin , Wu Gui Chao
Published: February 2011

Equal channel angular pressing (ECAP) of 3003Al ingot has been performed at room temperature, with an imposed equivalent strain of ~0.5 for single pass, and the refinement/distribution of inclusions and the hardness/dislocation of the alloy were examined. The results show that the first pass ECAP processing refined the inclusions (AlFe (Mn)Si) of the alloy considerably, with the size variation from 5-15μm length/1-2μm width to 1-3μm length/1-2μm width. In addition to the refinement, the first pass ECAP processing improved significantly the distribution of the AlFe(Mn)Si inclusions, and introduced high density of dislocations, leading to ~66.7 % increase of hardness. It was found that with the increase of number of ECAP processing passes, the distribution of AlFe(Mn)Si inclusions were increasingly more uniform, while the size of inclusions, the hardness and dislocation density (dislocation strengthening) of the alloy kept almost unchanged. The present results demonstrate the possibility of ECAP as an effective tool to refine AlFe(Mn)Si inclusions of aluminum alloys.
Influence of Cement Particle Size Distribution on Strength of Cement Paste
Authors: Zhu Bao Lin , Huang Xin , Guo Ye
Published: February 2011

On the basis of the principle for the highest filling degree of cement hydrates, it is synthetically considered that a matching connection between hydration of cement, volume increment of solid phase and packing density of cement paste, a calculation method for a connection between cement continuous particle size distribution and strength of cement paste is developed and tested by experiment. Based on above-mentioned analysis, a tentative research on the effect of particle size distribution of cement on strength is carried out.
Experiments for Strength Properties of Polypropylene Fiber-Reinforced Concrete
Authors: Shao Xiao Rong
Published: February 2011

This paper made experimental research on the compressive strength, axis compressive strength and splitting tension strength of polypropylene fiber-reinforced concretes at a fiber content of 0.9Kg/m3 in different ages which showed that: in the experiment of compressive strength, the strengths of C20 polypropylene fiber concretes in the ages was lower; the strength of C30 polypropylene fiber concretes in the age of 7 days was lower, the strengths in the ages of 14 days and 28 days were basically equal to; the strength of C40 polypropylene fiber concretes in the age of 7 days was basically equal to and in 28 days was higher than the strengths of ordinary concretes. In the experiment of axis compressive strength, the strengths of C20 polypropylene fiber concretes in the ages were lower; the strengths of C30 polypropylene fiber concretes in the age of 7 days and 14 days were lower and in the age of 28 days was basically equal to; the strengths of C40 polypropylene fiber concretes in the ages were basically equal to the strengths of ordinary concretes. In the experiment of splitting tension strength, the strengths of C20 and C30 polypropylene fiber concretes were lower; the strength of C40 polypropylene fiber concretes in the age of 28 days was basically equal to the strengths of ordinary concretes. Conclusion: the relationships between the strength of fiber concretes and ordinary concretes are correlated to the strength grades of concretes, namely, When the strength degrade of concretes is low, the strength of polypropylene fiber concretes is lower, but the strength reaches closer to or exceeds the strength of ordinary concretes along with the increase of the strength grade of concretes.
Mechanism of Preferential Adsorption of Carboxylic-Vinyl Copolymer, Hydroxy Carboxylate and Sulfonation - Polyol in Cement Hydration Process
Authors: Tan Hong Bo , Ma Bao Guo , Ke Kai , Xiao Jun
Published: February 2011

In the ternary system of hydroxy carboxylate (HC), sulfonation-polyol (SP) and carboxylic-vinyl copolymer (PC), HC and SP preferentially adsorb on the surface of particles to shield the initial hydration. In this way, the ternary system has excellent dispersibility and holding dispersibility, and it has little effect on later hydration. By means of the chemical shrinkage, SEM and XRD analysis, the hydration mechanism of the hydroxy carboxylate (HC) and sulfonation-polyol (SP) has been discussed and the preferential adsorption model (PAM) has been established. The results show that HC delays the initial hydration of C3S and accelerates both the hydration of C3A and the formation of AFt; HC reduces the strength for 28 d with the addition of 0.2%; SP delays initial hydration of C3S and C3A; the ability of shielding hydration becomes weaker along with cement hydrating and the development of strength is normal. In the ternary system of HC, SP and PC, HC and SP with the electrostatic attraction of -SO3- and COO- and complexation of OH- preferentially adsorb on the surface of particles and active hydrating points. Then, reaction of active hydrating points was shielded and the growth of the hydration products slows. In this way, hydration of C3A and C3S are delayed, and the holding dispersibility of PC becomes better. The PC preferentially adsorbs on inert hydrating points and consumes slowly to provide dispersibility with steric hindrance. Along with hydrating going on, organic compounds are enwrapped by hydration products and the shielding ability becomes weaker and weaker. Then, the hydration becomes normal.
Crack Research for Welded Joint of Steel Truss Bridge
Authors: He Zhong Shan , Liu Jia
Published: February 2011

Steel trusses are often used in the railway bridges.It is known that fatigue cracks may occour in the welded joints under the long-term dynamic loading. If the cracks are not detected and repaired in time, which may endanger the safety of bridges. This paper presents a solid element modeling method by the commercial finite element software package ANSYS, which can be used to model three dimensional cracked joint of bridge structures. Based on this method, the stress intensity factors are calculated. The results show that the modeling method is efficient and has a high precision for the stress intensity factor, which can be used to predict the fatigue life of the bridge.
Triaxial Shrinkages Tests of Unsaturated Compacted Clay
Authors: Wang Dong Lin
Published: February 2011

In this paper, The GDS unsaturated soil triaxial apparatus are employed for experimental tests to obtain the main characteristics of the drying paths for compacted clay. In order to study the soil water characteristic curve and shrinkage coefficient under deferent net mean stress. The results show that shrinkage index and the soil-water characteristic curve are dependent on net mean stress. At a given matric suction, with the increase of net mean stress, the void ratio and water content of soil sample is decrease, but the degree of saturation is increased.
Experimental Research on New Concrete Air Entraining Agent
Authors: Wang Bao Min , Tu Ni
Published: February 2011

Using waste to produce a new type of air entraining agent (AEA), carrying out research of the concrete’s mixture performance, mechanical properties and frost resistance durability after mixing with the AEA, with results showing that amount of air entrained in the concrete mixture and the water reducing rate increases along with the increase of the addition of the new AEA, and its compressive strength loss laws are similar with that of normal AEAs. During the frost-thaw cycle test, when the weight loss rate has reached its limit, concrete with the new AEA added can withstand almost 300 cycles, and at this time the relative dynamic modulus of the concrete, when the amount of air entrained in it is 4.5%, is 83.5%, and the relative dynamic modulus is 85.4% when the amount of air entrained is 5.3%. The addition of the AEA has obviously improved the pore structure of the concrete, and significantly raising its frost resistance durability.
Basalt Fiber Reinforced Concrete
Authors: Yang Yong Xin , Lian Jie
Published: February 2011

In this paper, mechanical performances of 480 specimens are tested and influences of basalt fiber ratio, slenderness, soakage material are studied. Results indicate that mechanical properties of BFRC are better than plain concrete. It can be found that the best mechanical performance may be get when the basalt fiber soaked by water-solubility material and its ratio at 8.4 to 14 kg per square meter as well as slenderness at 600 to 800.
Researches and Application of Railway Wind-Break Wall
Authors: Li Bo , Feng Shao Hua , Yang Qing Shan , Hou Ya Wei
Published: February 2011

Railway wind-break wall is widely used, which is of significant importance to prevent running vehicles from suffering the risk of overturning. In the paper, application of railway wind-break wall and specific details of its structure are introduced. Wind tunnel test and CFD simulation are widely used in the researches on the performance of railway wind-break wall and some important results are summarized. Based on the review, developments of railway wind-break wall in the future are provided.
The Study of Low-Velocity Impact Characteristics and Residual Tensile Strength of Carbon Fiber Composite Lattice Core Sandwich Structures
Authors: Lu Xai Mei , Ma Yun Fei , Wang Shi Xun
Published: February 2011

In this paper, low-velocity impact characteristics and residual tensile strength of carbon fiber composite lattice core sandwich structures are investigated experimentally and numerically. Low-velocity impact tests and residual tensile strength tests are simulated by the FE (finite element) software, ABAQUS/Explicit and its subroutine (VUMAT). In order to give more detailed description about the impact damage of the structure and improve modeling accuracy, multi-steps analysis method is employed to simulate impact process and residual tensile strength test in one analysis model. The calculation results computed by the FE model have been compared to the value of experiments, the difference of impact process simulation is about 3.3% and that of tensile strength test simulation is about 12.9%. The calculation error of computation model is acceptable, since unavoidable damage could be introduced in the courses of manufacture, processing and transportation of composite materials, and these damages are determinated difficultly in the computation programs. Next, the degradation tendency chart of residual tensile strength and impact energy threshold Uo of carbon fiber composite lattice core sandwich structures are obtained by the computation value of residual tensile strength after impacted with different impact energy. Previously, this threshold can only be obtained by experiment tests. After the contact force which is bigger than the threshold Uo impact on the sandwich structures, the residual tensile strength of structures are degraded greatly. This conclusion is significant for the design and application of carbon fiber composite lattice core sandwich structures.
Forecast and Analysis of Transformation Point of TC6 Titanium Alloy
Authors: Yin Ming Chu , Gao Tao , Chen En Zhi
Published: February 2011

Transformation point of titanium alloy is an important material parameter in hot forming and heat treatment for titanium alloy. Used the transformation points of TC6 titanium alloy determined by metallographic method as desired outputs, a model for forecasting the transformation point of TC6 titanium alloy was established using MATLAB neural network toolbox under the guidance of back propagation neural network. Used the established model to forecast the transformation point of TC6 titanium alloy and analyze the effects of the contents of nine elements on the transformation point of TC6 titanium alloy, and the results show that the transformation point of TC6 titanium alloy increases with enhancement of N, O, C and Al contents, while decreases with the enhancement of Cr, Si, Mo, Fe and H contents.
Effect of Cr and Zr Addition on the Corrosion Behaviour of Copper in the Chloride Solution
Authors: Zhang Ya Ni , Zheng Mao Sheng , Zhu Jie Wu
Published: February 2011

The corrosion behavior of CuCr, CuZr and CuCrZr alloys in NaCl solution is reported in this paper. The corrosion performance has been evaluated in NaCl solution atmosphere. The results show the corrosion resistance of pure copper decrease with the addition of the alloying elements initially. However, in the later exposure stages, the corrosion resistance of CuZr and CuCrZr alloy deteriorates significantly while the corrosion resistance of CuCr alloy is slightly better than that of pure copper. In addition, the results of the electrochemical experiments indicate that the different behavior for the element Cr and Zr in the base material and corrosion scales lead to the change of the corrosion resistance.
The Influence of Deformation on Dechromization Corrosion of CuCr Alloy in H3PO4 Solutions
Authors: Liu Yu Wen , Lu Wei , Song Jian Zheng , Liu Jian Hua , Zhang Rui Jun
Published: February 2011

The influence of deformation on dechromization of CuCr alloy in H3PO4 solutions was investigated by static immersion corrosion tests. The properties of undeformed and deformed alloys were characterised by XRD, Metallograph, SEM and X-ray fluorescence spectrometer respectively. It is observed that the deformation plays an important role in dechromization of CuCr alloys in H3PO4 solutions. Compared with undeformed one, the deformed CuCr alloy’s incubation time of corrosion is shortened, the concentration and temperature of H3PO4 solutions needed for dechromization decrease. Consequently the tendency of dechromization increases. Surface analysis showed that the microstructure of the dechromization layer is scarcely influenced. Finally, the dechromisation mechanism was discussed.
Mechanism of the Flux Improving the Microstructure and Mechanical Properties of AZ91D Magnesium Alloy
Authors: Wang Zhi Xiang , Liu Yang , Le Ya Ting , Liu Feng
Published: February 2011

The microstructures and mechanical properties of AZ91D magnesium alloy produced by two kind of fluxes were analyzed by using mechanical performance testing machine, optical microscope, differential thermal analysis (DTA), X-ray diffraction(XRD), scanning electron microscope（SEM）and energy dispersive spectrometer(EDS) analysis, etc.. The results show that the comprehensive properties of AZ91D magnesium alloy produced by the new flux named NF were better than traditional flux named RJ-2. Phase Mg17Al12 was improved enormously. In addition, not only the nuclear particle A14C3 was formed, but also the grain of the alloy was refined remarkably，and the σb，σs and δ were increased eventually. The tensile fracture surface was made of deeper dimples with rolling patterns, which was relevant to the smaller microstructure.
Numerical Simulation of Surface Hardened Layer of the Hydraulic Track
Authors: Bai Run Bo , Liu Fu Sheng , Xu Zong Mei
Published: February 2011

The surface of the large hydraulic track needs thermal treatment for hardening and tempering to improve its wear resistance and bearing capacities. Currently it is still difficult to simulate the hardened layer of the track. For that, this paper firstly put forward a surface layer hardness graded distribution model of the track, and then established a method to measure the hardness of the track in the finite element software. Based on the limit thinking, the meshes of the hardened layer of the track were refined, so as to achieve the purpose of using the discrete mesh to simulate the continuous change of the hardness graded distribution in the hardened layer of the track. Calculation results show that improving the hardness value and the thickness of the hardened layer of the track are benefit to the track’s bearing capacity and deformation stabilization.
Thermomechanical Properties and Morphology of Liquid Crystalline Polyurethane/Epoxy Resin Composites
Authors: Ban Jian Feng , Lu Shao Rong , Guo Dong , Liu Kuo , Luo Chong Xi
Published: February 2011

One new kind of epoxy resin toughening agent defined as liquid crystalline polyurethane elastomers (LCPUE) containing mesogenic ester groups and trithylene glycol flexible chain was synthesized and its nematic structure was observed by POM and XRD. The LCPUE was to modify the epoxy resin (E-51). The mechanical properties, fracture surface morphology, and thermal properties of the E-51/LCPUE curing system were systematically investigated. Experimental results revealed that the impact strength of the epoxy resin modified with LCPU is 1.9 times higher than that of the unmodified system, enhanced the thermal decomposition temperature by about 12 °C, and the fracture surfaces all modified systems display tough fracture feature.
Recent Progress on Carbon Coated Lithium Titanate
Authors: Zhu Yong Ming , Hu Hui Li , Weppner Werner
Published: February 2011

Being inherently safe and chemically compatible with the electrolyte, lithium titanate is considered alternatives to carbonaceous anodes in Li-ion batteries. Given the commercial success of the spinel lithium titanate, carbon coated lithium titanate, particularly in nano structured forms, have been fabricated and investigated for the applications. Nano structuring leads to increased reaction areas, shortened Li+ diffusion and potentially enhanced solubility/capacity. This paper reviews structural characteristics and electrochemical reactivity, along with synthetic approaches of carbon coated nanostructures and nano-composites based on lithium titanate, recently.
Experimental Research and Regression Analysis for Constant Temperature Drying of Wheat Straw
Authors: Hu Jian Jun , Zhang Quan Guo , Huang Hao
Published: February 2011

The constant temperature drying experiment on wheat straw at different initial moisture content and drying temperature were made with comprehensive thermal analyzer. The impact of initial moisture content, drying temperature and drying time on wheat straw procedure were reviewed, and the optimum drying result of wheat straw were gotten when initial moisture content was 32.5% and drying temperature was 100°C .The process of wheat straw drying was divided into three sections about preheating, constant temperature and falling rate drying. Regression equations on different sections were established by regression analysis, the result show that parabolic equation in preheating section, linear equation in constant rate drying section and power curve in falling rate drying section. Experiment data and reference frame from conclusion above were useful to crop straw drying technology.
Experimental Investigation on First Crack Strength and Crack Widthof Reinforced Concrete Beamsby Side-Bonding CFRP Sheets
Authors: Li Gui Bing , Sun Xiao Yan , Guo Yu Gang
Published: February 2011

Many flexural or tensile reinforced concrete members must be crack-free or the crack widths must be within specified limit value at service load levels. Presently, there are a number of structure members cannot satisfy its designed serviceability, due to the degradation of structural materials (due to durability problems) or by an increase in design loads. The use of bonding CFRP sheets on the side surfaces for strengthening or repair existing RC beamsis proposed to investigate the first crack strength and the cracking characteristics of RC beams. In order to verify the effectiveness of this application, experimental tests on six strengthened beams and one control beamhad been carried out. Experimental results demonstrated that this appears a promising technique both on improving the first crackstrength and on suppressing the crack width.
Preparation and Characterisation of Polyaniline Grafted Multiwalled Carbon Nanotubes/Epoxy Composite
Authors: Xu Jun , Ren Sheng , Wu Yao , Li Jian Gang , Li Mei , Guo Ying
Published: February 2011

Dodecyl benzene sulfonic acid (DBSA) doped polyaniline (PANI) grafted MWNTs (PANI-g-MWNTs)/Epoxy composite were prepared by aniline in situ polymerization in the presence of phenylamine groups contained MWNTs followed by solution blending and mould casting. Phenylamine groups grafted on the surface of MWNTs via amide bond join in the in situ polymerization and MWNTs are encapsulated by PANI coatings forming a core (MWNTs)-shell (PANI) nano-structure. DBSA doped PANI coatings swell in tetrahydrofuran (THF) and core-shell nano-structures are stabilized in epoxy solution, which is in favor of MWNTs dispersion in epoxy resin and formation of a homogenous MWNTs/Epoxy composite. After DBSA doped PANI-g-MWNTs are introduced in Epoxy, initial curing and exothermic peak temperatures as well as curing reaction enthalpy decrease, which indicates addition of DBSA doped PANI-g-MWNTs promotes curing reaction of Epoxy. Tensile strength, Young’s modulus, elongation at break, flexural strength and flexural modulus of the composite are improved by 71.7%, 42.3%, 99.8%, 55.01% and 39.86% compared with Epoxy, respectively.
The Effects of Particle Size-Matching Filling of Spherical Silica on the Flowability of Epoxy Molding Compounds for Large-Scale Integrated Circuits Packaging
Authors: Yang Ming Shan , Li Lin Kai , Liu Yang
Published: February 2011

By means of matching filling of five kinds of spherical silica with the particle size of 2μm, 3μm, 5μm, 10μm, 20μm respectively, the epoxy molding compounds(EMC) for integrated circuits(IC) were manufactured. Using classical particle accumulation theory, the particle distribution according with Dinger-Funk-Alfred equation was calculated by Matlab simulation software, and then the optimal particle size formulations were obtained. Adding the mixed silica according to the above optimal formulations into epoxy resin, the EMCs were manufactured by twin-roll compounding at 95~105°С . The melt viscosities of varied EMCs were measured by Rotating Rheometer. The results showed that the matching filling of different silica with different particle size can improve the flowability of EMC greatly.
Application of Carbon Fiber Composite on Space Camera Frame
Authors: Guo Quan Feng , Li Wei , Dong Ji Hong , Li Yan Chun , Wang Ke Jun , Wang Hai Ping , Zhao Wei Guo
Published: February 2011

General materials can satisfy the structure strength requirement of space effective payload easily. But it can hardly satisfy the structure stiffness requirement of space payload. Carbon fiber composite has many excellent properties, such as high relative strength, high relative stiffness, small expansion coefficient, good fatigue resistance and excellent vibration resistance. It can be used to make space products. Firstly, this paper discussed the properties of carbon fiber composite material. Compared with common materials, such as aluminum alloy and titanium alloy, carbon fiber composite material is more suitable for applications of space instruments. Secondly, the metal part embedded technique of carbon fiber composite structure was studied. According to the carbon fiber composite structure of a space camera frame, a few structure forms of embedded part ware studied. A space camera frame of carbon fiber composite was designed and manufactured. Finally, finite element analysis and mechanical tests on the space camera frame was carried out. The results reveal that the characteristic frequency of carbon fiber composite frame is up to 104Hz.The space camera frame is of high stiffness and dimensional stability.
High Performance Si-Si3N4-Sic Sagger Composite Materials Preparation and its Attack Mechanism after Usage
Authors: Zhai Ya Wei , Li Yong , Liu Lei , Zhu Xiao Yan , Wang Jia Ping , Sun Jia Lin
Published: February 2011

Si-Si3N4-SiC composites was prepared by firing at 1450°C for 8hrs in air atmosphere with SiC, Si3N4, Si as principal raw materials. Si-Si3N4-SiC composites has good performance and its services life is 5~7 times than that of oxides sagger. This paper also studies the material attack mechanism and observes the microstructure of Si-Si3N4-SiC composites which has been used 15 cycles.
Progressive Damage Model of FRP Composite Laminates with Central Hole
Authors: Sun Chong Qiang , Zhang Jian Yu , Fei Bin Jun
Published: February 2011

Progressive damage method is adopted to predict the static mechanics properties of FRP composite laminates with central hole. Progressive damage models with three different 3D failure criteria and material degradation models are established and analyzed via a user defined subroutine embedded into the general FEA package. Numerical results indicate that all the three 3D failure criteria can simulate the failure process of FRP laminates with central hole, but the final failure load is different. Degradation coefficient and the finite element mesh have significant effect on the numerical results.
Structure and Properties Study of Porous Silicon Carbide Composite Based on SLA
Authors: Jin Jie , Ni Maolin , Wang Shen Hao
Published: February 2011

In the article, porous silicon carbide composite is prepared based on stereo lithography apparatus (SLA). The microstructure of porous silicon carbide composite is characterized by mean of scanning electron microscopy (SEM). The properties of porous silicon carbide composite are studied, such as surface HV and corrosion resistance, and the influence of the pore agent content to mechanical properties.
Microstructure and Compressive Behaviour of 3D Needled C/SiC Composites
Authors: Fan Shang Wu , Zhang Li Tong , Cheng Lai Fei , Xu Fang
Published: February 2011

The 3D needled C/SiC composites were fabricated by chemical vapor infiltration combined with liquid melt infiltration. The microstructure and compressive behavior of 3D needled C/SiC composites were investigated. The results indicated that the 3D needled C/SiC composites were composed of the layers of 0 ° non-woven fiber cloth, short fiber web, 90 ° non-woven fiber cloth, and needle fibers. The materials were composed of carbon fiber, PyC, Si, and SiC. SiC and Si were mostly distributed in the short fiber web layers. Local C/C units (local carbon fiber reinforced PyC) were formed in the fiber bundles of non-woven fiber cloth. A great deal of pores and cracks existed in the 3D needled C/SiC composites. The pores less than 10 μm were generally located in the non-woven cloth layers, while the big pores were in the short fiber web layers. The cracks were regularly presented in the Si and SiC region of the composites and were normal to the axial direction of the fiber bundles. The compressive strengths perpendicular and parallel to the non-woven fiber cloth were about 118±18 MPa and 260±41 MPa, respectively. The compressive fractography revealed stepwise fracture along fiber layers direction.
Precipitates and Lüders Elongation in Ferritic Stainless Steels Stabilized with Ti and V
Authors: Gao Fei , Zhang Wei Na , Zhang Zhi Bo , Liu Zhen Yu , Wang Guo Dong
Published: February 2011

The influence of finish rolling temperature on the precipitates and Lüders elongation in ultra purified ferritic stainless steels stabilized with Ti and V has been investigated, in which the hot rolled bands were produced by conventional rolling process and the finish rolling at relatively low temperatures. It was shown that finish rolling at relatively low temperatures promoted the formation of a large number of fine MC precipitates, which were denser in dispersion and finer in size than those formed in conventional rolling process by strain-induced precipitation, and consequently scavenging of interstitial atoms in solid solution, indicating that the finish rolling at relatively low temperatures can be the effective way to significantly reduced Lüders elongation for the final sheets. These results have been confirmed by the internal friction measurements.
Preliminary Research on Interfacial Evolution Behaviour of Ti-Cu Laminated Composite Materials
Authors: Yang Hong Mei , Zhu Pei Xian , Zhou Sheng Gang , Xu Jian , Ma Hui Yu , Guo Jia Xin
Published: February 2011

Ti-Cu laminated composites were fabricated by means of vacuum hot pressing (VHP). The Ti-Cu interfacial reaction was studied to observe the microstructural changes. Scanning Electron Microscopy (SEM), Energy Disperse Spectroscopy (EDS) and X-Ray Diffraction (XRD) were used to observe morphology and analyze phase composition of interfacial reaction zones. With increasing the holding time, the thickness of the reaction zones varies from 12μm to 16μm. The results show that there are 5 binary intermetallic compounds (Cu4Ti, Cu4Ti3, CuTi, Cu3Ti2, CuTi2) observed in the Ti-Cu diffusion couples held at 1073 K for 1h, 1.5h, 2h and 2.5h respectively under the pressure of 10MPa.
Random Response and Statistic Characteristics Analysis of Random Parameters Nonlinear Systems
Authors: You Feng Xiang , Lu Fu He
Published: February 2011

The geometric parameters of composite used in structure usually has the random properties. It is very significant for the reliability and optimization of structure design to research the random response and statistic characteristics of random parameters nonlinear systems. In this article, we use both of perturbation method and random central different approximation method to study the random response of random parameters nonlinear systems under uncertainty, get one kind of approximate iteration relationship of square response, and analyze the statistic characteristics of random parameters anti-symmetrically laminated plate.
Effect of Quenching Temperature on Microstructures and Mechanical Properties of Boron-Nickel-Added Nb-Treated HSLA H-Beams
Authors: Xiao Wang , Wang Zuo Cheng , Wang Xie Bin , Li Xian Da , Gao Jun Qing , Zhao Xiu Ling , Dong Chang Xing
Published: February 2011

To lower the fracture appearance transition temperature (FATT) of Nb-treated HSLA H-beams further, boron-nickel-added Nb-treated HSLA H-beams were tempered after they were quenched at 870, 910 and 950°C respectively. Microstructures and mechanical properties, especially low temperature toughness of the experimental steels were investigated by scanning electron microscopy (SEM), uniaxial tensile test and Charpy impact test (V-notch). The results indicate that the FATTs of quenched & tempered specimens are all below -70С and that of some specimens is even below -90°С . Tensile strength of all quenched & tempered steels and their total elongation value are above 570 MPa and 21 % respectively. It can be seen that dual-phase microstructure of ferrite and tempered martensite in steels leads to the best low temperature toughness, and carbides along grain boundaries are beneficial to low temperature toughness.