bluuebunny/crossref_metadata_2025 huggingface dataset:
500MPa Seismic Rebars Developed by Nitrogen-Rich and Vanadium-Microalloyed, Controlled Cooling Technology
Authors: Chen Wei , Shi Zhe , Zhao Yu , Cao Jian Chun , Yu Yu Mei
Published: February 2011

500MPa high-strength seismic rebars was developed by nitrogen-rich & vanadium -microalloyed, controlled cooling technology in domestic steel plant of china, microalloy precipitates, microstructure, mechanical properties, welding performance and aging properties of rebars were researched by using metallographic microscopy, scaning electron microcopy, transmission electron microscopy, x-ray diffraction apparatus, flash-butt welding and mechanical properties testing. The results show that a large number of the dispersed V (C, N) precipitates are precipitated in the grain boundary, dislocation line and the ferrite matrix, precipitation size in the ferrite matrix is 10~ 20nm, V(C,N) precipitates amount accounts for 67.54% of the total amount of vanadium in steel, effect of precipitation strengthening is remarkable; when termination temperature after controlled cooling for rebars is controlled at 710°C ～750°C , the core microstructure is polygonal ferrite and pearlite, ferrite grain grade is 11.0, outer layer microstructure is acicular ferrite, pearlite and a small amount of bainite, good effects on fine-grain strengthening and seismic performance are obtained; rebars have low strain aging and good welding performance; production cost is reduced by RMB 100 Yuan per ton steel compared with VN micro-alloyed and hot-rolling process, benefit is obvious.
Study on Rapid Manufacturing of CAFÉ Injection Mold
Authors: Yue Yan Fang , Zhang Yong Di , Yang Guang , Wang Jin Ye , Wei Bin
Published: February 2011

Rapid tooling developed from the rapid prototyping technology is a new method and technology of mold making, and this paper mainly studies the composite aluminum-filled epoxy (CAFÉ) mold，which is one of the rapid bridge toolings, applied to thermoforming of the plastic parts. The material formula of the CAFÉ mold with E51 as matrix is developed, and using the formula we have made the CAFÉ mold for the back shell of a cell phone charger, which is installed at the injection molding machine to do the test and finally successfully obtain the polypropylene sample. In addition, the process of making the CAFÉ mold is described in detail in the paper.
Solid Modeling and Machining Approach of the Impeller Based on Five-Axis Machine Tool
Authors: Zhao Yu Xia , Di Jie Jian , Gao De Wen
Published: February 2011

An impeller is the core of aviation engine components, the processing quality has a decisive impact on the performance of the engine. An impeller is also one of the most important basic components of centrifugal compressor. When a three-axis CNC machining centre is used for producing an impeller, great difficulties, i.e. collisions between the cutting tool and the impeller, can occur. As the surface is normally twisted in design to achieve the required performance, it can cause overcut and collision problems during machining. To solve these problems, an integrated five-axis machining approach for a centrifugal impeller by combining related machining technologies is developed. As a result, Cutter Location data based on the geometry model of blade and hub of the impeller are generated. Finally, the Cutter Location data is verified through software simulation. The results prove that the machining methodology adopted is useful and efficient.
An Evaluation Model of Enterprise Informatization Level Based on Grey Whitenization Weight Cluster Analysis
Authors: Yang De Ling , Chen Wan Ming
Published: February 2011

According to the existing insufficiency of researches of enterprise informatization level evaluation, building an evaluation model of enterprise informatization level based on grey whitenization weight cluster analysis. First, based on the existing research, build an evaluation index system of enterprise informatization level. Then, by using grey incidence analysis idea, put forward a method to determine index weight. And then, construt an evaluation model of enterprise informatization level based on grey whitenization weight cluster analysis. Finally, test the validity of the model through the application example.
Effect on Microstructure and Hardness of Plunger Piston of Fe-Based Composite Coating by Laser Cladding
Authors: Zhao Yong Tao , Li Wen Xue , Zhou Jun Wei
Published: February 2011

The laser cladding of Fe power technology was used to repair worn plunger piston surface. The microstructure of cladding layer, binder course and the matrix were observed by OM and SEM. Besides, the micro-hardness of different zones was measured through micro-hardness testing. The results show that the matrix metal microstructure of plunger piston is made of ferrite and austenite. By laser cladding Fe-based power on base metal, the cladding layer grain is fine and uniform, grain growth has obvious direction and finally become dendrites oriented, the microstructure of cladding layer is both second-phase hard particles and Fe-based solutes. The combination between matrix and cladding layer is smooth, belong to metallurgy bonding. The hardness of cladding layer is higher than that of other parts in three parts, the max value of micro-hardness is about 1250HV, it can agree with wear resistance need of plunge piston surface.
Study on Extraction of Dioscin from D.zingiberensis
Authors: Li Xiang , Ma Jian Zhong , Xia Jing
Published: February 2011

The effects of extraction conditions on Extraction of Dioscin from D.zingiberensis was studied in this paper. It was shown that when the ultrasonic frequency was 35.74KHz, solid-liquid ratio(D.zingiberensis:ethanol)was 1:10, ethanol volume fraction was 75%, and extracted for 30 minutes and for 3 times, the extraction rate of dioscin from D.zingiberensis reached the highest. The method of ultrasonic-assisted ethanol extraction can not only cut down extraction time, but also increase extraction yield.
Effect of Direct Current on the Semi-Solid Isothermal Heat-Treated Microstructure of ZA84 Magnesium Alloy
Authors: Yang Ming Bo , Liang Xiao Feng , Zhu Yi
Published: February 2011

The effect of direct current on the semi-solid isothermal heat-treated microstructure of ZA84 alloy is investigated. The results indicate that it is possible to produce ZA84 alloy with non-dendritic microstructure by semi-solid isothermal treatment. Furthermore, imposing direct current during the semi-solid isothermal treatment of ZA84 alloy can accelerate the non-dendritic structure evolution of the alloy. Under the experimental conditions of this work, higher the current density, quicker is the rate of non-dendritic structure evolution for the semi-solid isothermal heat-treated ZA84 alloy. Further investigations need to be considered in order to optimize the current density, isothermal temperature and holding time.
Influencing Factors of AZ31B Sheet Deep Drawing
Authors: Gao Jun , Yue Zhen Ming , Lin Shu Xia
Published: February 2011

Magnesium alloys have been attracting much more attentions due to its low density, high specific strength and its lightweight during the past 30 years. In this paper, the deep drawing performance of AZ31B magnisium alloy sheets at elevated temperature was studied by the experimental approach. The results indicated that the formability of the AZ31B sheets at elevated temperatures could be improved significantly. The best external forming parameters can be obtained such as heating temperature of sheet, die-punch clearance, punch fillet radius, etc. Simulating the forming process by using the numerical simulation software, we investigated the stress-strain distribution, thickness distribution and forming limit, etc. The thickness distribution by the numerical simulation agrees well with the experimental results.
The Real-Time Monitoring Tool States Based on Wavelet Analysis
Authors: Peng Zhong Bo , Li Ji Lei , Han Xue Feng , Yan Jun
Published: February 2011

Monitoring of tool condition is one of the most important techniques to be developed in the automatic cutting processes as it can help to prevent damages of machine tools and work pieces. Power monitoring technique is an effective method for identifying tool states. However, it is difficult to distinguish sources which led to the power signal drop. In order to solve the problem, wavelet transform algorithm was adopted to define inflexion of power signal, and wavelet threshold denoise technique was used to separate the characteristic inflexion of power signal. The simulation results show that the method is capable of detecting the cutting condition effectively.
Study on the Acquisition Method of a Digital Model for Oral Cavity Teeth Based on Point Cloud
Authors: Yue Yan Fang , Wei Bin , Yang Guang , Zhang Yong Di , Wang Jin Ye
Published: February 2011

The requirement of constructing the three-dimensional entity model for oral cavity teeth has been put forward to the research of the orthodontics based on rapid prototyping technology. This paper compares the merits and demerits of the CT scanning and the structured light scanning and finds a method of acquiring the digital model of oral cavity teeth based on the point cloud. Adopt the structured light scanning technology and 3DSS software to acquire the files of the point cloud data, and introduce the files into GeoMagic software. After processing the data files we obtain the high-quality digital model of oral cavity teeth. The optimal scheme and the processing procedure of the point cloud data in GeoMagic software are described in detail in the paper. In addition, we compare the final solid model and the point cloud data and analyses the errors.
Experimental Research on Improving Wear Resistance of Coating Surface by Magnetron Sputtering
Authors: Luo Yue Hao , Zhang De Yuan , Chen Hua Wei
Published: February 2011

Magnetron sputtering metallic or non-metallic materials on epoxy resin coating surface can effectively reduce the friction, improve the wear resistance and inhibit the abrasion, loss and so on. Sputtering Ti/C on the epoxy resin coating can modify the surface, it is proved that the friction can be reduced and wear resistance can be improved on different levels by the experimental results, and in this paper, the mechanism of friction reduction and wear resistance improvement is also investigated and researched comprehensively. By analysis, the layered structure produced by sputtering C can play an important role of lubricating, and the diamond film or diamond-like carbon film can exist on the coating surface, which can play an important role of wear resistance. This study lays the foundation for research on the modification of coating surface.
CrN Films Deposited by Middle Frequency Magnetron Sputtering
Authors: Zou Chang Wei , Zhang Jun , Xie Wei , Shao Le Xi
Published: February 2011

CrN films with deposition rates of 30-190 nm/min were deposited on Si (111) substrates by middle-frequency magnetron sputtering methods. XRD, SEM, EDS and microhardness tests were used to investigate the effects of bias voltages and total gas pressure on the structure and mechanical properties of the resulting CrN films. With the increasing of bias voltages and total gas pressure, the preferential diffraction orientation changed from (111) to (200). A smooth surface was observed by the SEM experiments and the thickness of the film was about 2 µm. The deposition rates and Cr content of resulting films were highly influenced by the magnitude of the bias voltage and total gas pressure. RMS and Ra properties of the CrN films increased when increased total gas pressure or decreased bias voltage. CrN films produced under optimal conditions have an almost 1:1 Cr:N ratio as determined by EDS. The hardness of the CrN film increased from 2200 to 2700 HV when increased the bias voltages from 0 to 200 V.
Low Cost Vibrometer Utilizing Laser Diode Self-Mixing with Sound Card Controlled by LabVIEW
Authors: Huang Zhen , Li Cheng Wei , Feng Wu Chang , Zhu Mao Yuan
Published: February 2011

A compact and versatile vibrometer is designed based on self-mixing laser diode vibrometry interference to measure the oscillation amplitude of a piezoceramics (PZT). A fraction of the light emitted by the laser diode (LD) is reflected by the PZT, and then mixes with the light inside the cavity, causing a modulation of the laser output. The self-mixing signal is detected by the photodiode accommodated in the LD package and acquired by a data acquisition and processing system based on sound card and LabVIEW. Amplitude of the PZT is detected by fringe counting. According to results of test, this device can measure the vibration signal with a measurement accuracy of λ/2. The measurable oscillation amplitude range from 0.325 um to 6.5um
The Micro-Mechanical Behavior of Inclusions under Tensile Load in X80 Pipeline Steel
Authors: Tong Ke , Li Shao Hua , Zeng Yan Ping , Liu Qiang , Han Xin Li
Published: February 2011

In-situ tensile tests with specially designed SEM were conducted to trace the entire process of crack initiation and propagation till fracture in X80 pipeline steel. The mode of crack initiation induced by inclusions under tensile load was investigated. The results show that: (1) All the inclusions crazed and fracture was the typical tensile fracture, which indicates that the inclusions have little effect on the tensile properties of the X80 material under tensile load. (2) When the size of inclusion is larger than the critical size, crack initiated at inclusion/matrix interface first, and could easily propagate into matrix，but the long crack cannot form. When the size of inclusion is smaller than the critical size, cracks first formed in the inside of inclusions but not propagate into matrix. (3) If the area of cross section of round inclusion is less than 100μm2, crack initiated firstly in the inside of inclusion. If the area of cross section of round inclusion is larger than 100μm2, crack initiated firstly at the inclusion/matrix interface. For the rectangle inclusion, when its area of cross section is below 150μm2, cracks usually initiate in the center of inclusions.
Effect of Cold-Rolled Process Parameters on Deep-Drawing Performance of Micro-Carbon Steel
Authors: Liu Zhan Ying , Liu Yang , Wang Yu Qian , Chen Jin
Published: February 2011

Through the rolling and performance test, effect of cold-rolled micro-carbon steel rolling parameters and annealing temperature has been obtained on deep-drawing properties. Rolling texture was detected by X-ray diffraction and analyzed by a quantitative of ODF. R-plastic strain ratio was consistent with texture analysis, which provided with a basis for formulating the process parameters of cold-rolled and annealing of micro-carbon steel.
Corrosion Behavior Research of Fe3Al Intermetallic Compound in H2S/CO2 Environment
Authors: Wang Bin , Bai Jiang Hu , Zhou Dong Mei , Jiang Zhong Ying , Yang Zhen , Zhang Jun Ling
Published: February 2011

The corrosion behavior of Fe3Al was studied by high temperature autoclaves in H2S/CO2environment. By Stereo Microscope, we found that the corrosion film of Fe3Al is thin and crack at 60°C, 4.0 Mpa,after 72h in autoclaves; Phase analysis by XRD showed that the main composition of corroded products is FeS; its corrosion are Ⅲ corrosion resistant type and corrosion rating of 4, mainly pitting, and average corrosion rate of 0.2106 mm/a.
Research on Droplet Transfer of MIG Welding with Alternating Longitudinal Magnetic Field
Authors: Zhu Sheng , Wang Qi Wei , Yin Feng Liang , Liang Yuan Yuan , Wang Xiao Ming
Published: February 2011

The stress and motion state of droplet in MIG welding with alternating longitudinal magnetic field were analyzed, and the impact of alternating longitudinal magnetic field on the droplet transfer were studied by high-speed video camera. The results show that the droplet is spherical approximately and transfer to molten pool along the welding wire axis without external longitudinal magnetic field. When alternating longitudinal magnetic field was introduced into welding process, the droplet rotate around the welding wire clockwise and counter-clockwise alternately. Shape of droplet became flat and direction of transfer deviated from the welding wire axis under the action of magnetic field. As the exciting current increased, extent of deviation from the wire axis increases. When the exciting current is too large (I >20A), extent of deviation is too large and droplet are disintegrated into several small droplet during the transition. So droplet can not transfer into molten pool successfully and the bead can’t be formed.
Kinematic Analysis and Optimization Design of an Eccentric Crank Slide-Block Mechanism Based on ADAMS
Authors: Wang Yu
Published: February 2011

Operating principle and motion characteristics of an eccentric crank slide-block mechanism are analyzed. A virtual prototype model of the eccentric crank slide-block mechanism is set up based on ADAMS,a simulation software. The kinematics analysis of the eccentric crank slide-block mechanism,it is given.Under the premise of meeting the requirements of slide stroke and travel velocity-ratio coefficient, based on ADAMS, each component size of the eccentric crank slide-block mechanism with best pressure angle (α max ) min can be easily obtained. The equations and the calculations can be used in engineering practice.
Prognosis of Alkali Aggregate Reaction with SEM
Authors: Zhang Xin Yu , Gallucci Emmanuel , Scrivener Karen
Published: February 2011

Alkali aggregate reaction (AAR) is known leading to great damage in concrete, both in compressive strength and in durability. In this study, a backscattered scanning electron microscopy with energy dispersive spectroscopy is adopted to diagnose AAR reaction. The results show that the type of AAR reaction and reaction products can be easily identified and the method is precise and fast.
Study on Mechanical Properties of Soda Residue / Fly Ash Composite Cementitious Material
Authors: Li Bao Jia , Li Guo Zhong
Published: February 2011

The composite cementitious material was prepared with soda residue and fly ash. The mechanical properties were improved by mixing calcined lime and Portland cement, and the mechanism of admixture was researched. The results showed that the 28d flexural strength reached 3.59MPa and the 28d compressive strength reached 9.71MPa., when the proportion of soda residue and fly ash was 40:60 with 9% Portland cement and 7% calcined lime added.
Research on Application Technology of TLA Modified Asphalt Mixture
Authors: Feng Xin Jun , Zha Xu Dong
Published: February 2011

Marshall test design methods are used to design TLA modified asphalt mixture and base asphalt mixture respectively, and their pavement performance is tested. The results showed that there is a transforming coefficient of 1.10 between optimum asphalt content (OAC) of 25% TLA modified asphalt mixture and that of base asphalt mixture, and TLA modified asphalt mixture has excellent high temperature stability, capacity of moisture-resistance damage and impermeability. Construction technology of TLA modified asphalt mixture is similar to that of ordinary asphalt mixture, but the key for it is to control construction temperature, uniformity and compactness of TLA modified mixture.
Mechanical Property of Solidified Concrete by Explosion as Concrete is in Flow Pattern
Authors: Wang Hai Liang , Cui Zhuo , Li Chuan , Bao Ru Cang
Published: February 2011

We have made the concrete test blocks, which were blasted by different charge quantities in the semi-infinite soil. Using the SHIMADZU Universal Testing Machine AG-X250kN system, we performed the uniaxial compression test, studied the stress-strain curves of concretes by explosion, under the same condition curing and the standard curing. The results show that, concrete will have higher compression strength by explosion. And there is an optimal charge quantity, when the concrete consumption is given. With this optimal charge quantity, compression property of concrete by explosion is superior to concrete cured at standard.
Research on Performance of Cement Stabilized Skeleton-Dense Structure Aggregate Base Course Material
Authors: Hu Li Qun , Sha Ai Min
Published: February 2011

Laboratory tests were conducted to evaluate the performance of cement stabilized “skeleton-dense structure” aggregate and conventional “suspended-dense structure” aggregate. In this study, both of the aggregates above were stabilized by cement with different cement content (2%, 3%, 4%, 5% and 6%). Performances of the prepared specimens were studied in terms of compaction property, 7 day unconfined compressive strength (UCS), thermal shrinkage coefficient and 30 min erosion quantity. Results indicated that the maximum dry density of cement stabilized “skeleton-dense structure” aggregate is bigger than that of cement stabilized “suspended-dense structure” aggregate slightly. On the contrary, the optimum moisture content of the former is slightly smaller than that of the latter one. Along with the increase of cement content, the 7 day UCS and thermal shrinkage coefficient of cement stabilized two aggregates were all increase, and 30 min erosion quantity of cement stabilized two aggregates were all decrease. At the same cement content level, the 7 day UCS of cement stabilized “skeleton-dense structure” aggregate is greater than that of cement stabilized “suspended-dense structure” aggregate, and the thermal shrinkage coefficient and erosion quantity in 30 min of the former is smaller than that of the latter.
Mesoscopic Thermal-Mechanical Fire Damage Modeling of High Performance Concrete
Authors: Zhao Jie , Zheng Jian Jun , Peng Gai Fei , van Breugel Klaas
Published: February 2011

High performance concrete will undergo thermal-mechanical degradation or even spalling under high temperature conditions, such as fire, and the safety of concrete structures will be endangered. To prevent concrete from fire damage, the damage mechanism should be thoroughly understood. In this paper, an anisotropic damage model is presented to analyze the thermal-mechanical degradation of concrete. The vapor pressure and the moisture transport are taken into account. The damage evolution history can be traced with the temperature propagation and the degree of material degradation can be predicted through the model.
Experimental Study on Dynamic Mechanical Behaviour of Concrete with High Temperature
Authors: Jia Bin , Li Zheng Liang , Cheng Lu , Yao Hua Chuan
Published: February 2011

An experimental system of high-temperature split Hopkinson pressure bar (SHPB) was developed by combination of the split Hopkinson pressure bar (SHPB) and microwave heating system, then tests of concrete whose temperature changed from room temperature to 650°С and impact velocity from 5m/s to 12m/s were completed. Based on the test results, the dynamic strength of concrete increases with increasing impact velocity whether with high temperature or room temperature, meanwhile the dynamic strength of concrete with high temperature has the strain rate effect, but the effect keeps decreasing with temperature increasing, even at temperature above 500°С , compressive strength will not have strain rate sensitive effect any longer when strain rate surpasses a certain value. In the meantime, the strain rate hardening effect is coupled with high temperature weakening effect, but the latter has greater influence.
Research Status and Prospects of the Smart Concrete
Authors: Sun Jie , Ding Wen Xia
Published: February 2011

Smart concrete is the product of modern building materials combining with modern technology and the advanced stage of the traditional concrete development. But the smart concrete material is currently in the research and laboratory stage and is far away from large-scale practical application stage. The history and developing status of the smart concrete were reviewed. The definition and classification of the smart concrete were discussed in detail. The developing trend and prospects of the smart concrete were analyzed and some problems were proposed.
The Study on the Properties of Super Absorbent Polymer in Expansive Concrete
Authors: Pang Lu Feng , Cai Yong Tao , Chang Qing Shan
Published: February 2011

This paper considers the application of Super Absorbent Polymer(SAP) in expansive concrete with different cementitious materials. The macroscopic properties of concrete have been researched through testing restricted expansive rate and mechanic properties of concrete after adding SAP. The test result shows that SAP can promote cement hydration while keeping concrete a good volume stability. By means of scanning election microscopy (SEM) and spectroscopy , the submicroscopic structure of SAP concrete is analyzed in order to explain its macro-properties.
Effect of Particle Size on Expansive Behaviour of MgO-Based Expansive Agent in Cement Paste
Authors: Zhang Zhi Bin , Xu Ling Ling , Tang Ming Shu
Published: February 2011

In order to investigate the effect of particle size on expansive behavior of MgO-based expansive agent (MEA), linear expansion of paste containing MEA and hydration process of MEA in paste were measured. The results indicated the expansion of paste increased with the drop of particle size at early age, however, MEA with lager particle size expanded faster at late age. Finally, the expansion of paste increased with the rise of particle size. MEA with larger particle size was detrimental to the soundness of cementitious matarials. These two rules were more obvious to MEA burned at higher temperature. In addition, the hydration degree of MEA increased with the drop of particle size.
Experimental Study on the Bending Resistance Performance of GFRP Tube Filled with Steel-Reinforced High-Strength Concrete Flexural Component
Authors: Zhou Le , Wang Lian Guang , Li Sui , Liu Hong Tao
Published: February 2011

This paper presents the experimental research on the bending resistance performance of 3 GFRP tube filled with steel-reinforced high-strength concrete flexural members. It studies that the GFRP tube fiber tangle angle, and GFRP tube thickness of GFRP tube filled with steel-reinforced high-strength concrete flexural members have an effect on mechanical performance of this investigation. The experimental results show that the flexural bearing capacity of members obviously increases with the decrease of the fiber tangle angle. The bearing capacity of flexural members increases with the thickness increase of GFRP tube. Based on the test study and theory analysis, a calculation method is proposed, and good agreement with the test results is achieved.
Enhancing the Toughness of Heavy Thick X80 Pipeline Steel Plates by Microstructure Control
Authors: Nie Wen Jin , Xin Wei Feng , Xu Tian Ming , Shi Pei Jian , Zhang Xiao Bing
Published: February 2011

The experiment results show that the microstructure control plays a key role for enhancing toughness of heavy thick X80 plates at low temperature, especially DWTT property. The toughness of heavy thick X80 plate at low temperature is not only related to the bainite grains and M/A islands, but also impacted by the original austenite grain size. Finer original austenite grain size benefits to increase the BF/AF ratio in volume of a base material enlarge the crystal orientation difference of microstructure transformation inside austenite. Cracks on a broken section of DWTT samples can (a) penetrate the coarse grains directly, (b) propagate in Zig-Zaga way in the fine grains, and (c) be around the boundary of original austenite grains. The stable and high toughness of heavy thick X80 steel plates from the mass production can be achieved at low temperature made with the reasonable chemistry, clean steel, non-defect slab technologies and OHTP rolling practice.
Effect of Ultrasonic Power on the Microstructure and Hardness of Commercially Pure Aluminum
Authors: Wang Hai Chuan , Liu Dan , Liao Zhi You , Li Ming , Lie Jie , Wang Gui , Dargusch Matthew S.
Published: February 2011

Molten, commercially pure aluminum has been treated ultrasonically with differing input power. The results show that the ultrasonic power can significantly refine the microstructure of the aluminium and increase the hardness of the samples. A mathematical model developed in this paper can predict the effect of the ultrasonic power on the grain size of the pure aluminium well.
Plastic Strain Energy in Low-Cycle Fatigue of A356 (Al-7Si-0.4Mg) Aluminum Alloys
Authors: Song Mou Sheng , Ran Mao Wu
Published: February 2011

In this paper, the problem of plastic strain energy density as a evaluation of low-cycle fatigue (LCF) properties for A356 alloys with various Ti content and Ti-addition methods is considered. The experimental results reveal that it is not the Ti-addition methods but the Ti content that has played an important role in influencing on the plastic strain energy density, thus on the LCF life. Whether for the electrolytic A356 alloys or for the melted A356 alloys, the alloys with 0.1% Ti content can consume higher cyclic plastic strain energy during the cyclic deformation compared with the alloys with 0.14% Ti content due to the better plasticity, giving rise to a better fatigue resistance and a longer LCF life. Because of the different macro or micro deformation mechanism, the fracture surface of electrolytic A356 alloy exhibits the diverse microstructural morphologies under the various strain amplitude.
Effect of Element Re on Creep Behaviour of a Single Crystal Nickel-Based Superalloy
Authors: Liu Hui , Wang Ming Gang , Tian Su Gui
Published: February 2011

By means of measuring creep curves and microstructure observation, the influence of the element Re on creep behaviour of the single crystal superalloy has been investigated. Results shown that the creep resistance of nickel-based superalloy with element Re may be obviously improved and the 2% Re superalloy had lower strain rate and longer creep lifetimes compared with Re-free single crystal alloy. The activation energy and stress exponent of the 2% Re superalloy during steady state creep were measured to be Q =478.6 kJ/mol and n = 5.1 respectively. The deformed features of the 2% Re alloy during primary creep are dislocation slipping in the matrix channels, dislocation networks are formed by dislocation reaction, and creep resistance may be improved when networks on the γ/γ’ phases interfaces. In the tertiary creep stage, deformation mechanism is the <110> super-dislocation shearing into the rafted γ’ phase.
Effect of Trace Boron on Microstructure and Mechanical Properties of Ti-9V-3Al-3Cr-3Zr-3.5Mo Alloy
Authors: Liu Xu Liang , Ma Yun Qing , Yang Shui Yuan , Wang Yun Neng , Wang Cui Ping , Liu Xing Jun
Published: February 2011

The effects of trace boron on microstructure and mechanical properties of β type Ti-9V-3Al-3Cr-3Zr-3.5Mo (wt. %) alloy have been investigated in this study. Upon the addition of 0.02 wt. % boron, the grain size of the B-modified alloy was almost four times smaller than that of the B-free alloy. Accordingly, the tensile strength and elongation of B-modified alloy increased from 712 MPa and 14.6 % to 813 MPa and 17.9 %, respectively, mainly due to the effect of grain refinement.
Effect of Sr + RE Combination Modifier on Microstructure and Mechanical Properties of Al-40 Wt％ Si Alloy
Authors: Li Xiao Song , Hu Wei , Cai An Hui , Chen Hua , Zhou Yong
Published: February 2011

The effect of the Sr + RE complex modifications on microstructure and mechanical properties of Al-40 wt% Si alloy were investigated. The results show that Sr + RE complex modification not only on primary silicon and eutectic silicon with modification, but also on dendrite α significantly refine. When the addition of RE remain unchanged, with increasing of the addition of Sr, the primary silicon firstly changes from polygonal block or large plate to small block, then to large polygonal block, edge and corner passivations. The eutectic silicon firstly changes into a fine start with a long needle-like fibrous or branched further to a short stubby dendrite or worm-like, The eutectic silicon changes from needle to a fibrous sheet plus short rod, then to short rod end for the dense, or even granular. The dendrite α changes from highly developed dendritic to equiaxed and uniform distribution. In addition, with increasing of the addition of Sr, the mechanical properties has been significantly improved, tensile strength increased by 37%, elongation is more than double, the hardness increased by 21%. When the Sr addition is between 0.05 wt% and 0.077 wt%, the microstructure and mechanical properties are the best.
Microstructures and Properties of Cu-Cr-Y Alloy after Cold Worked and Aging
Authors: Guo Shou Hui , Zhang Meng , Peng Guo Yin , Tang Jian Cheng
Published: February 2011

The influence of cold-worked and aging processes on the microstructures, mechanical properties and conductivity of Cu-Cr-Y alloy has been experimentally investigated. Samples were cut from ingot of Cu-0.8 wt.%Cr-0.05 wt.%Y alloy. They were solution-treated, cold rolled and aging treated. The results show that the Cu-Cr-Y alloy, with 70% deformation and aging at 480°C for 24min, can reach an excellent combination of microhardness and conductivity. The microhardness and conductivity is about 143HV and 84%IACS, respectively. The microstructures by transmission electron microscopy (TEM) show that the fine and dispersed distributed Cr precipitate, which form due to decomposition of the supersaturated solid solution during aging, is responsible for the peak maximum microhardness as it is predominantly present in the peak aged hardening condition.
Hot Corrosion of Cobalt-Based Alloy with (Na, K)2SO4 Coating at 900 °C
Authors: Fu Guang Yan , Zhao Xin , Liu Qun , Su Yong
Published: February 2011

The hot corrosion behavior of pure Co, Co-10Cr and Co-10Cr-5Al alloys coated with (4～4.5) mg/cm2 (Na, K)2SO4 deposits has been studied at 900 °C in air by thermogravimetry and SEM/EDX analysis. The results show that hot corrosion rate of Co-10Cr alloy was obviously higher than that of Co-10Cr-5Al alloy and hot corrosion rate of pure Co was between those of the two cobalt-based alloys. Both alloys produced complex corrosion scales, containing an outermost layer of pure cobalt oxide and an inner layer where the oxides of both alloy components were simultaneously present on the Co-10Cr alloy, while a middle layer containing CoO and Cr2O3 and an inner layer of Al2O3 with a few aluminum sulfides appeared on the Co-10Cr-5Al alloy. The results were interpreted by taking into account the effect of active element and hot corrosion mechanism.
Effect of Temperature on Recrystallisation Texture and Microstructure for Non-Oriented Silicon Steel under Asymmetrically Rolling Process16
Authors: Zhang Zheng Gui , Liu Yan Dong , Wang Fu
Published: February 2011

The effect of temperature on the recrystallization texture and microstructure of non-oriented silicon steel under asymmetrically rolling condition was quantatively studied using X-ray diffraction technology. The results show that the texture component accumulates around {111}<112> when annealed at 800°C. Texture intensity is high and grain size is uniformly distributed between 50μm and 100μm with best magnetism. When annealed at 850°C and 900°C, texture component is scattered and the grain size is also bigger. However, for the annealing at 750°C, the texture component is similar to cold rolled process. The grain size is small and non-uniform, which is unfavorable to magnetism. The difference of forces along the fast and slow side of the roller results in different deformation texture and further affects the intensity of recrystallization texture along the two sides of the roller.
Study on the Thermal Fatigue Resistance of Cr17Mn10Ni3 Heat-Resistant Steel
Authors: Liu Jun You , Liu Jie , Zhao Qing he , Song Jin Xiu
Published: February 2011

In order to prolong the life of inner liner of coke can, the thermal fatigue property of Cr17Mn10Ni3 heat-resisting steel was analyzed and studied from cast metallurgical structure, the morphology of crack surface and cross-section, the injury factor by OM, SEM, photoshop and imagetool software. The results shows, Cr17Mn10Ni3 has a good thermal fatigue property because of the microstructure with good thermal conductivity, austenite matrix and break carbide lying in treelike crystals. It decreases the innerstress and postpones the time of crack formation and extension, during the process with 1100°C and room- temperature water cooling. The cracks mainly appear in the phase interfaces between carbides and matrix, ferrite and austenite, and grain boundaries. The thin and deep cracks with high concentration are beneficial to relax the elastic strain energy. But a single and thick crack easily widens and deepens to be detrimental to the thermal fatigue property.
Effects of Two-Step Aging Temperature on Exfoliation Corrosion of an Al-Zn-Mg-Cu Alloy
Authors: Chen Xu , Liu Zhi Yi , Lin Liang Hua , Bai Song
Published: February 2011

The effects of two-step aging temperature on exfoliation corrosion of an Al-Zn-Mg-Cu alloy were characterized by EXCO test, electrochemical test and TEM observations. Results suggested that the partial recrystallized structure is susceptible to exfoliation corrosion which is greatly influenced by intergranular corrosion. The transfer current of the sample aged at 170°C (second-step aging temperature) is higher than that of the sample aged at 155°C. The second-step aging temperature exhibits more contributation to the exfoliation corrosion in this investigation, compared to the first-step aging temperature.
Synergistic Inhibition Effect of Sodium Silicte and Phytic Acid for Carbon Steel in Neutral Salt Water
Authors: Ma Hong Yun , Yi Shou Zhi , Zhang Qin
Published: February 2011

The inhibition effects of sodium silicate, phytic acid and their mixtures in 5% NaCl solutions have been investigated using weight loss method and Tafel polarization techniques. The surface morphology of carbon steel was obtained using scanning electron microscopy (SEM). The results show that the co-addition of 70 mg∙1-1 sodium silicate and 5 g∙1-1 phytic acid has the optimum inhibition efficiency (84.15%) and the lowest corrosion rate (0.13 g∙m-2∙h-1). Compared with their individual inhibition effects, the optimum inhibition efficiency of sodium silicate is 62.17% at 90 mg∙1-1 and phytic acid is 80.05% at 15 g∙1-1, respectively. The results obtained from weight loss method and Tafel polarization curves are in good agreement. The results show the enhanced inhibition effect by the inhibitors mixtures.
A Study on Corrosion of Cast-On-Strap Alloys
Authors: Li Ai Ju , Chen Hong Yu , Dou Long Chuan , Wang Hui , Zhang Wei
Published: February 2011

The effects of different Sn or Se content on the corrosion behavior of lead-Sn or Pb-Sn_Se alloy in sulfuric acid solutions were investigated by metallurgical microscope, SEM, and weight loss tests. It was found that the addition Sn acts as grain coarser, but Se acts as grain refiner and Pb-Sn-Se alloys feature smaller grains. SEM for the corrosion layer indicated that the intergranular corrosion occurs on the surface of alloys with high Sn content (>1.wt%), but the general corrosion occurs on the surface of Pb-Sn alloys with low Sn content (<1.wt%) and all Pb-Sn-Se alloys. And The structure of corrosion layer and the eroded degree are relative to the height of the strap alloys above the plate. And the 1cm strap alloy above the plate was cathodically protected and almost no corrosion problems appeared. The corrosion rate of alloys containing Se is lower than Pb-Sn binary alloys. And the higher of Se content, the lower of corrosion rate. The results demonstrated that Pb-Sn-Se alloys show the potential for application as the negative strap in VRLA batteries.
Solid Solution Strengthening of Sm in Mg-10Y-1.5Sm Alloy
Authors: Zhang Qing , Li Quan An , Jing Xiao Tian , Li Chang Qing
Published: February 2011

By microstructure analysis and microhardness measuration, solid solution strengthening of Sm in Mg-10Y-1.5Sm alloy after solid solution and aging treatment was investigated. The results show that the microstructure of the alloy consists of α-Mg matrix and Mg24Y5 phase, and fine Mg24Y5 particles distribute in α-Mg matrix uniformly and dispersedly. No new phase forms after Sm addition, and Sm enhances α-Mg matrix and Mg24Y5 phase by solid solution effect. Compared with that of Mg-10Y alloy, the microhardness of the alloy with Sm addition increases obviously from HV87.7 to HV98.5.
Sensitivity Analysis of Static Response for Composite Laminated Plates in Hamilton System
Authors: Xu Jian Xin , Li Ding He
Published: February 2011

A hybrid governing equation of the static response quantities and its sensitivity coefficients is derived for the composite laminated plates in the state space framework. Analytical and semi-analytical methods are given by using the trigonometric functions and B-spline wavelet on the interval (BSWI), respectively. Numerical results obtained by the semi-analytical methods are presented showing the effects of variation in the material properties of the plate on the displacement response quantities and their sensitivity coefficients. And the accuracy problem is also discussed by using these numerical results. Because of the use of the hybrid governing equation in the response analysis and sensitivity analysis, the convoluted algorithm is avoided in sensitivity analysis, and the response quantities and its sensitivity coefficients are obtained at the same time. The hybrid governing equation can also be easily modified to solve the sensitivity analysis problems of stiffened piezolaminated plates, or the plates and shells with piezoelectric patches or Fiber Metal Laminates.
Study on Manufacture Technology and Mechanical Properties of Three Dimensional Braided Composite Support with Irregular Shape
Authors: Sun Ying , Yang Jian , He Ye Hong , Li Jia Lu
Published: February 2011

The composite components with irregular shape are often used in many application areas. Normally the formation of the composite components with irregular shape is by laminated technology. However the main problem of laminated composites is that there is a pure resin area between two lays which will degrade the mechanical properties of composite components. Three dimensional (3D) integrated braided composite can overcome this problem. In this paper, the design and manufacture technology of 3D integrated braided composite support with irregular shape were researched, including: braiding technology of 3D braided preform of composite support, the determination of process parameters of resin transfer molding(RTM) for 3D braided composite support, and the design of mold for consolidation of composite support. The compress property and shear property of this composite were investigated. The maximum compress force borne by this composite support is 2.31 kN, which is more than the design value of 1.90 kN and the maximum shear force borne by this composite support is 4.48 kN, which is more than the design value of 4.10 kN. The weight of 3D braided composite support is only 60.27% of the weight of titanium support.
Effects of Particle Size and Volume Fraction on Extrusion Texture of SiCp/Al Metal Matrix Composites
Authors: He Chun Lin , Wang Jian Ming , Cai Qing Kui
Published: February 2011

The texture development was investigated in the extruded Al and Al metal matrix composites (MMCs) reinforced with SiC particles of different sizes and volume fractions. During extrusion, both the unreinforced Al and the MMCs develop a strong fiber texture with two components: <111> and <100>. When SiC is introduced into aluminum, the main component of texture is not modified, but the intensity of the component evolves with the volume fraction and average size of SiC particles. For the MMCs reinforced with 3.5μm SiC particles, the texture intensity of the Al matrix tends to decrease as the SiC volume fraction increases, and it is lower than that in the unreinforced Al. However, for the MMCs reinforced with 25 nm and 150 nm SiC particles, the texture intensity of the Al matrix is higher than that in the unreinforced matrix, and it increases with increasing the SiC volume fraction. It is found that superfine particles may introduce some new component into the deformation texture, and the texture intensity increases as the SiC particle size decreases.
The Influence of Enamel Firing Process on Microstructure and Mechanical Properties of Steel Substrate
Authors: Zhang Ai Wen , Jiao Si Hai , Jiang Zheng Yi , Sun Quan She , Wei Dong Bin
Published: February 2011

The as-rolled and enamel fired microstructure and mechanical properties of two low carbon steels with different compositions were analysed in the paper. The results show that the grains do not coarsen in lab firing process, and could be refined after industrial enamel firing process. The strength can keep stable in the firing process and the impact energy could be enhanced greatly under the industrial enamel firing process. The surface decarburized layer was occurred as a result of chemical reaction among the carbon in steel and water, oxides in the enamel frit.
The Stability Research of Montmorillonite/Octadecyl Trimethyl Ammonium Complexes
Authors: Qiu Jun , Lu Xian Jun , Sun Li Jun , Wang Gui Fang , Li Peng , Zhang Zhong Wei
Published: February 2011

In order to study the stability of Montmorillonite / Octadecyl trimethyl ammonium complexes in engineering application, the influences of the organic modifier dosage, oscillation intensity, oscillation time, temperature, pH, sodium salt concentration, calcium salt concentration on the stability of Montmorillonite / Octadecyl trimethyl ammonium complexes were systematically investigated. Research results show that the stability of Montmorillonite / Octadecyl trimethyl ammonium complexes slightly reduces with the increases of oscillation intensity, oscillation time and temperature, but the impact isn’t obvious. The more the organic modifier dosage is, the more unstable the Montmorillonite / Octadecyl trimethyl ammonium complexes are. The stability of the Montmorillonite / Octadecyl trimethyl ammonium complexes decreases significantly under the medium conditions of lower or higher pH. The higher the concentration of sodium salts is, the more stable the Montmorillonite / Octadecyl trimethyl ammonium complexes are, but calcium salts are on the contrary.
Preparation and Flame Resistance of Hydrotalcite/Epoxy Nanocomposites Containing Red Phosphorous
Authors: Zhang Ya Tao , Zhang Yan Wu , Zhang Hao Qin , Liu Jin Dun
Published: February 2011

In this study, the intercalated hydrotalcite (HT)/epoxy (EP) nanocomposites containing red phosphorous (RP) (HT-RP/EP) were prepared by in-situ polymerization. Firstly, low-molecular-weight polyamide 6 (PA6)/HT nanocomposite was prepared in the presence of organ-hydrotalcite with alanine as an initiator at 150°C. And then, PA6/HT composite and a certain amount of RP incorporated into epoxy resin in the presence of curing agent (polyamide 650) and HT-RP/EP nanocomposite was prepared successfully. Finally, the micro-structure and flame resistance were characterized by scan electron microscope (SEM) and vertical burning method, respectively. The results showed that HT was dispersed in the epoxy matrix evenly. HT-RP/EP nanocomposites showed significant flame resistance. When the content of both of HT and RP was 5%, the flame resistance achieved FV-0 level.