bluuebunny/crossref_metadata_2025 huggingface dataset:
Continues Cooling Transformation Behavior of Low Carbon Mn-Nb-B Steel
Authors: Duan Zheng Tao , Li Yan Mei , Zhu Fu Xian , Zhang Hui Yun
Published: September 2011

The continues cooling transformation (CCT) of a low carbon Mn-Nb-B steel in the undeformed and deformed conditions were investigated, respectively. The CCT diagrams of the steel were constructed. The microstructures and microhardness were analysized. The results showed that the microsructures contains ferrite, pearlite, granular bainite, acicular ferrite and lath bainite depending on cooling rate; Deformation moved the CCT curve to the top left corner, increased the transformation start temperatures slightly, and promoted the formation of ferrite and pearlite. Furthmore deformation also fined the transformed microstructures.
The Study on the Low Yield Strength for Super Fine Grain and High Strength Bearing Nb if Steel
Authors: Zhang Hong Mei , Qiao Li Feng
Published: September 2011

The cold rolling and simulative continuous annealing experiments after rolling were carried out in the laboratory on the base of super fine grain (SFG) steel sheet. The microstructure and the second-phase particles precipitated behavior were analyzed by the technology of OM, TEM and EDX. It is found that the fined Nb(C, N) can be formed by adding micro-alloy element Nb. It is noted that the yield strength is low as well as the tensile strength is high by the PFZ which is free of precipitate called precipitated free zone on the one side of the grain boundary. Contrast to the conventional IF steel, the super fine grain steel has super fine grains and gives excellent press-formability such as low yield strength, high r-value（the plastic strain ratio）. High strength cold-rolled steel sheets (HSS) with high formability have been developed in the last decade, in which the major strengthening method was solid-solution hardening with silicon, manganese and phosphorous [1-3]. When the IF steel is strengthened with the high amount of solid-solution elements, it becomes susceptible to the secondary work embrittlement because of the lack of grain boundary strength [4-6]. In this paper, High strength cold-rolled steel sheets (HSS) with high formability have been developed for the IF steel-bases. The grain reﬁnement and precipitation hardening are achieved by means of the ﬁne distribution of carbide under the appropriate combination of the relatively higher carbon content near 0.0070 mass% with niobium. As the result, this type of IF-HSS has been successfully developed to reach a higher r-value as compared with the conventional IF-HSS.
Dynamic Search Structure Failure Path Method Based on Element Birth and Death Technology for Overhead Traveling Crane
Authors: Xu Ge Ning , Wang Jian Hua , Yang Rui Gang
Published: September 2011

For providing basic data to the reliability evaluation of the carrying capacity of the overhead traveling crane’s structure, by using Visual C++6.0 development platform, Pro/Toolkit and the element birth and death technology, the parametric model of the overhead traveling crane’s structure and the automatic analysis of the structure finite element model have been achieved. The results from the analysis obtained maximum element stress from each load step, and then the failure paths of the structural element which undered static load were found, from which the failure order consistented with failure development law of the overhead traveling crane’s structure, this would provide a technical basis to the search of dynamic failure paths which undered dynamic load. Finally, engineering examples which verified the feasibility of this method were brought.
Synthesis and Luminescent Behavior of Mn(1-X)S:AX/ZnS Core/Shell Nanocrystals
Authors: Li Li Hua , Gu Yong Jun , Xie Rui Shi , Zhu Jian Guo
Published: September 2011

Mn(1-X)S:AX/ZnS (A: Er, Dy) nanocrystals were synthesized by chemical precipitation method. X-ray diffraction analysis show that Mn(1-X)S:AX/ZnS nanocrystals were zincblende structure. The high-resolution transmission electron microscope images indicated that Mn(1-X)S:AX/ZnS nanocrystals show a spherical shape, and their average grain size is about 4 nm. Photoluminescence spectra of Mn(1-X)S:AX/ZnS nanocrystals revealed that there existed several major emission bands, ～417 nm, ~509 nm, ~580 nm, ~617nm and ~680 nm. Mn(1-X)S:AX/ZnS nanocrystals exhibited enhanced luminescence properties compared with the pure Mn(1-X)S:AX nanocrystals. The enhanced photoluminescence properties of Mn(1-X)S:AX/ZnS nanocrystals should be attributed to the effective suppression of nonradiative recombination by the surface-passivation layer.
Numerical Simulation for Flow Field in Hydrocyclone
Authors: Zhang Fu Lun , Deng Song Sheng , Hua Wei Xing
Published: September 2011

According to the RNG model and the Euler method, the flow field inside hydrocyclone is simulated by the CFD. The results show that: the internal flow field of the hydrocyclone is quite complicated, which means that the fluid flow parameters in the same location vary widely within different directions, such as track, velocity, separation and so on. The flows of cylindrical section and conical section are very different, at the same time, the main separation process is completed in the conical section. In the hydrocyclone with single entry, the center of the flow field is not in the position of geometric center; which will influence the stability of the flow field and the separation.
A Nonlinear Study on the Prestressed Structure of High Strength Concrete - Steel Fiber Concrete
Authors: Wen Hua Bin , Zhan Yu Lin , Liu Hai Bo
Published: September 2011

In the construction of high-rise buildings, large span structures and tall structures, the combinatorial design structure of high strength concrete, steel fiber concrete, prestressed tendon and ordinary steel bar is a main measure to bring the advantages of high strength concrete into full play. This paper studies the nonlinear constitutive relations of high strength concrete, steel fiber concrete and steel bar. By using finite element method, this paper carries out a numerical simulation of the whole monotonic loading process of box prestressed continuous beam of high strength concrete - steel fiber concrete and gets comparatively detailedc calculating results, which provide a theoretical reference for the reasonable combinatorial design of high strength concrete,steel fiber concrete, prestressed tendon and ordinary steel bar.
Corrosion Behaviors of QSn4-3 under Two Kinds of Marine Advantage Bacteria Environment
Authors: Gu Cai Xiang , Du Xing Hua , Zhu Guan Jun , Yin Yan Sheng , Li Wen Ge
Published: September 2011

Polarization curves, corrosion potential, scanning electron microscopy (SEM) were adopted to investigate the corrosion behaviors of QSn4-3 under two kinds of marine advantage bacteria (anaerobic SRB and facultative anaerobic Vibrio natriegens) environment. The results show that the microbial film has some effects on inhibiting corrosion of QSn4-3 at the early stage of corrosion; the existence of marine microorganisms accelerates the corrosion process of QSn4-3; the combined action of SRB and V.natriegens accelerates the corrosion obviously and QSn4-3 coupon is more prone to pitting corrosion.
Effect of Heat Treatment and Composition on Grain Size and Lamellar Spacing of a Lamellar TiAl Alloy
Authors: Chang Xia , Zhang Xiao Bin , Zhang Ji
Published: September 2011

The article presents the results of optical microscopy, scanning electron microscopy (SEM), Transmission Electron Microscope (TEM) conducted on a Ti–46.5Al–2.5V-1.0Cr–0.3Ni alloy before and after different heat treatments. Heat treatment of the alloy at 1340°C followed by cooling leads to the formation of the fully lamellar microstructure which consists of γ lamellae mostly and of small amount of α2 lamellae. The cooling rate of 50°C/min in alloy tcx1-G produced an optimal microstructure. This cooling rate generated finest lamellae with the smallest individual lamella spacing among the alloys.
In Situ Production of Fe-TiC Surface Composite
Authors: Wang Jing , Ding Yi Chao , Cheng Hong , Wang Yi San
Published: September 2011

TiC particulates reinforced iron matrix surface composite was produced by cast technique and in-situ synthesis technique. The surface composite was investigated from thermodynamics, microstructure, wear-resistance and oxidation-resistance. The results show TiC particles whose volume fraction is about 40% exhibit fine size in iron matrix on the surface composite. An excellent metallurgy-bond is observed between the surface composite and the gray iron. Fe-TiC surface composite shows good oxidation-resistance at 900°C and great wear-resistance under condition of dry sliding.
Study on Fatigue Crack Propagation at Negative Stress Ratio in 2A12 Aluminum Alloy
Authors: Bai Shi Gang , Zhang Jia Zhen , Sha Yu
Published: September 2011

This paper intends to get compressive loading effect on fatigue crack growth of 2A12 aluminum alloy. The fatigue crack propagation tests at negative stress ratio R=-0.5, -1and -2 were made in different applied compressive loading. The result showed that the effect of the compressive loading part of the applied stress cycle on fatigue crack growth rate in 2A12 aluminum alloy at negative stress ratio can not be omitted.
Electrochemical Behaviors of Pb-Ca Alloys and Pb-Ca-SnX-Al Alloys under 60°C in 5mol•L-1 H2SO4 Solution
Authors: Wang Li Zhen , Zhang Kai Qing , Gu Shu Hua , Zhang Yong
Published: September 2011

Abstract: The microscopic structure of Pb-Ca alloys and Pb-Ca-SnX-Al alloys was observed by scanning electron microscope (SEM). The high temperature effect on corrosion behaviors and anode film Pb(Ⅱ) of Pb-Ca alloys and Pb-Ca-SnX-Al alloys was studied using linear sweep voltammetry, electrochemical impedance spectra (EIS) and AC voltammetry. It was found that the oxidation tendency of t-PbO to nonstoichiometric oxide PbOx and PbSO4 to ß-PbO2 may be increased at high temperature. With the increase of tin content, total corrosion and harm of corrosion can be reduced, the resistance of anode film decreased and the ions motion tendency enhanced.
Microstructure and Properties of Microwave Sintered 40 wt. % WC Steel-Bonded Carbides
Authors: Luo Jun Ming , Wei Zheng , Xu Ji Lin , Deng Li Ping
Published: September 2011

40 wt. %WC steel-bonded carbides were prepared by microwave sintering. The sintering behavior and mechanical properties of 40 wt. %WC-Fe were investigated in comparison with 0 wt. %WC-Fe. The green compact of 40 wt. %WC-Fe sintered at 1280 °C, the phase transition between WC and Fe is observed, generating new Fe2W2C phase. The phase transition promotes the densification of the sample, which plays a strengthening effect on the material. Microwave sintering possesses even quicker densification than conventional sintering, as well as substantially higher mechanical properties. The microhardness and bending strength of steel-bonded carbides prepared by microwave sintering are 10% ~ 20% higher than the conventional sintering. The microhardness of 40 wt. %WC-Fe is up to 544 HV, eight times higher than that of 0 wt. %WC-Fe and the bending strength of 40 wt. %WC-Fe is three times higher than that of 0 wt. %WC-Fe. Strengthening mechanism of 40 wt. %WC-Fe samples is that the Fe2W2C rigid phase dispersed over the steel matrix is not deformation, and plays the effect of hindering dislocation motion. The fracture mode is mixed intergranular fracture and transgranular fracture, belonging to brittle fracture.
Investigation on the Preparation Processes of Cu-Bi Master Alloy
Authors: Zhang Li Na , Liu Bai Xiong
Published: September 2011

The Microstructure of Cu-Bi master alloy with different melt processes, such as different melting temperature and holding time, was observed by PHILIPS-XL30 scanning electron microscopy (SEM); phase analysis was conducted by Miniflex X-ray diffraction(XRD); Magix(PW2424) X-ray fluorescence analyzer(XRF) was used to analyze chemical compositions of Cu-Bi master alloy. The results show that there are Cu and Bi two phases in the Cu-Bi master alloy; The yielding rate of bismuth decreases with the rising melting temperature. It decreases slowly between 1100 °C to 1150 °C,while it decreases rapidly between 1150 °C to 1200 °C.The bismuth particles in the Cu-Bi master alloy prepared at 1100 °C are much larger than those prepared at 1150 °C,while the size of bismuth particles change little from 1150 °C to 1200 °C. So the better melting temperature of preparing Cu-Bi master alloy is 1150 °C.The yielding rate of bismuth decreases with the holding time increasing. But when the holding time is too short, there are large bismuth particles in Cu-Bi alloy .So the better holding time is 120s.
An Efficient and Environmentally Friendly Method for the Preparation of PMMA Microcapsules
Authors: Guo Sheng Wei , Wang Gu Xia , Han Feng Lan
Published: September 2011

Polymer microcapsule is a kind of functional material with unique structure. Study on the preparation methods is growing obviously. An efficient and environmentally friendly method for the preparation of polymer microcapsules is presented in this article. PMMA microcapsules were prepared by ultrasonically initiated miniemulsion polymerization phase separation method. The morphology, size and its distribution of PMMA microcapsules were investigated by transmission electron microscopy (TEM), atomic force microscopy (AFM) and dynamic light scattering (DLS). And the polymerization kinetics was also discussed. The results show that PMMA microcapsules with size of ca. 100 nm can be obtained when the amount of coemulsifier is 3 times of that of the emulsifier, the amount of monomer is 3 wt% of the system and the reaction temperature is 80°C. In all experiments, N2 was bubbled to protect the reaction system.
The Choice of the Simulation Skin in the Experiment of Dynamic Moisture Transfer Based on Munsell Color Index
Authors: Wu Xuan Run , Cao Jian Da
Published: September 2011

The function of the simulation sweating device when done the experiment of dynamic moisture transfer based on Munsell color index was needed to simulate the state of the human body sweating as far as possible, the performance of the simulation skin would directly affect the stability of experimental results. This paper by selecting the four kinds of materials as an alternative of the simulation skin had carried out the experiment of dynamic moisture transfer based on Munsell color index and had done the analysis of variance of experimental results, and had found that results were significantly different when using different simulation skins. Further had done the test of the preserving water rate of seven representative materials, test results show that: the 2 # simulated skin 95% cotton knitted +fabric 5% op had the best preserving water performance, the 2 # simulated skin 95% cotton knitted +fabric 5% op could been chosen as the outer layer of simulated skin .the 6 #, faux suede had better similarity with morphology of human skin tissue. So, it could be chosen as in the layer of the simulated skin.
Development of Surface Roughness Prediction for Steel in CNC Turning by Using Response Surface Method
Authors: Chanphong Siriwan , Tangjitsitcharoen Somkiat
Published: September 2011

This research presents the development of the surface roughness prediction in the turning process of the plain carbon steel with the coated carbide tool by using the response surface analysis with the Box-Behnken design. The effects of cutting parameters on the cutting force and the cutting temperature are investigated. The cutting force and the cutting temperature are measured to help analyze the relation between the surface roughness and the cutting conditions. The models of cutting force ratio and the cutting temperature are also proposed based on the experimental data. The surface plots are constructed to determine the optimum cutting condition referring to the minimum surface roughness.
Study on Electrochromic Performance of the Copolymer Based on 4-(1H-Pyrrol-1-Yl) Phenyl 4-(1H-Pyrrol-1-Yl) Butanoate with 3,4-Ethylenedioxythiophene
Authors: Ou Yang Mi , Lv Xiao Jing , Hu Bin , Zhang Cheng
Published: September 2011

A new polypyrrole derivative 4-(1H-pyrrol-1-yl) phenyl 4-(1H-pyrrol-1-yl) butanoate (NPB) was synthesized by chemical method and characterized by 1H and 13C NMR spectroscopy. A new copolymer based on NPB and 3,4-ethylenedioxythiophene(EDOT) was electrochemically synthesized. Cyclic voltammogram and spectroelectrochemical characterization showed that the copolymer film had a well-defined reversible redox process as well as electrochromic behavior. Moreover, the copolymer film exhibited a multicolor electrochromism at different potentials, fast switching time of 0.8 s at 365 nm and an optical contrast of 17% at 1100nm.
Ni-Induced Lateral Fast Crystallization of Amorphous Silicon Film by Microwave Annealing
Authors: Sun Jie , Shi Wei Ming , Yang Wei Guang , Zhou Ping Sheng , Wang Lin Jun
Published: September 2011

Polycrystalline Si (poly-Si) thin films for application to display devices and solar cell are generally fabricated by crystallizing amorphous Si (a-Si) thin film precursors. In this paper, studies on Ni-induced lateral crystallization of a-Si thin films by microwave annealing at low temperature were reported. The crystallization of a-Si thin films was enhanced by applying microwaves to the films. The poly-Si films were invested by Optical Microscopy, X-ray Diffraction (XRD) , Raman Spectroscopy and Scanning Electron Microscope(SEM). After processing of Ni-induced lateral crystallization by microwave annealing above 500°C, the a-Si has begun to be crystallized with large grains having the main (111) orientation. The rate of crystallization at 550°C is about 0.033μm/min. Compared to Ni-induced lateral crystallization by conventional furnace annealing, Ni-induced lateral crystallization by microwave annealing both lowers the crystallization temperature and reduces the time of crystallization. The crystallization mechanism during microwave annealing was also studied. The technique that combines Ni-induced lateral crystallization with microwave annealing has potential applications in thin-film transistors (TFT’s) and solar cell.
Preparation and Performance of Zr(Ca)-Al-O-N Composites by Reaction Sintering of Al-ZrO2(Ca) in N2 Atmosphere
Authors: Bu Jing Long , Wang Rong Lin , Wang Zhi Fa , Yu Li Xue
Published: September 2011

Zr(Ca)-Al-O-N composites were prepared with ZrO2(Ca) (i.e Ca-PSZ, d50 < 10 μm) and Al powder (d50 =7.5 μm, 29 μm, and 62 μm) as raw materials by in situ reaction sintering in N2 atmosphere at 1600 °C. Phase constiturion of the composites was affirmed by XRD and SEM-EDS, and effect of grain size and content of Al powder on sintering performance of the composites was investigated, and oxidation characteristic of the composites were analysed by measure increasing weight of oxidation. The results showed that major phases of the composites composed of (t+c)-ZrO2, ZrN, ZrAl3O3N and CaAl12O19, and Al powder of 5 wt% - 7 wt% d50 =7.5 μm and 3 wt% - 5 wt% d50 =29 μm were suitable for preparation of the composites and bendiing strength of its samples sintered at 1600 °C had 60-90MPa. In atmosphere, oxidation onset temperature of Zr(Ca)-Al-O-N composites were approximately 550 °C, and the end temperature of its oxidening were approximately 950 °C. Treating with antioxidation is a key for application of Zr(Ca)-Al-O-N composites.
Integrative Technology Evaluation Model (ITEM) for Selective Laser Melting (SLM)
Authors: Merkt Simon , Hinke Christian , Schleifenbaum Henrich , Voswinckel Holger
Published: September 2011

This paper focuses on the evaluation of manufacturing processes that are competing with Selective Laser Melting (SLM). In 3D-part production of serial parts SLM is starting to be an economic choice for manufacturing. An integrated technology evaluation model (ITEM) is presented that helps decision makers to determine the potential of SLM while comparing with conventional manufacturing technologies. In contrast to conventional evaluation methodologies the ITEM considers interactions between product and process innovations generated by SLM. The paper closes with a technical and economical evaluation of a test part from Festo AG to validate two important parts of the ITEM.
Comparative Study of the Two Bar Billets for Bevel Gear Based on Multi-Objective Comprehensive Assessment
Authors: Tong Ying
Published: September 2011

The two bar billets with different height-diameter ratio in enterprise were studied on the process of gear blank thermal forming. The rigid-viscoplastic finite element simulations in multifactor coupling condition of stress ,heat and wear were established. The metal flow in the process was simulated. The temperature distribution and varying of the mold and blank was forecast. The single-step wear depth and distribution of the die in forging was analysed based on Archard ,which provided sufficient data to evaluate life of the die. The reasonable aspect ratio for blank can be obtained upon the results, which will offer basis to the product.
Study on TC4 Titanium Alloy by Laser Oxygen-Diffused Hardening Process under Different Gas Atmosphere
Authors: Chen Chang Jun , Zhang Min , Chang Qing Ming
Published: September 2011

Surface oxygen diffusion hardening treatments of TC4 titanium alloy in Ar+O2, O2 and ambient atmosphere were performed by scanning with a pulsed Nd: YAG laser. By using different gas atmosphere with Ar+O2, O2 and ambient atmosphere, the structure and the hardness behavior of the laser oxygen hardening layers can be controlled in a wide range. Optical microscope (OM), scanning electron microscopy (SEM), energy dispersive analysis system of X-ray (EDAX) was used to reveal the microstructure and to identify the chemical composition. A Vickers microhardness tester was employed to measure the hardness distribution across both the substrate and the hardening layer. It is shown that smooth, deep and crack-free harden layers of a surface hardness ranging from 810-673Hv can be obtained under ambient atmosphere and Ar+O2 atmosphere. Cracks are observed in the sample processed under pure oxygen atmosphere. Dilution of oxygen gas with argon or nitrogen (ambient atmosphere) leads to a crack-free harden layer at the expense of a reduction in surface hardness.
Brazing RB-SiC Used in Large Aperture Space Optical System
Authors: Zhang Bin Zhi , Zhang Zhong Yu
Published: September 2011

Because of the sic material’s superior optical characteristic, machine characteristic and hot characteristic, it becomes currently the space big aperture reflector choose firstly1. For larger aperture sic mirror, it is not economical and safe to make the monolithic body directly2,3. The SiC mirror brazed assembly with several segments can solve these problems. In this paper, one Φ600 mm sic plane mirror as demonstration welded with 3 radial segments is roughly grinded to the required figure at first, then the mirror is finely grinded and polished by the technology of CCOS, the mirror figure error is less than 1/20λ (λ = 632.8nm) in RMS finally. The problems of the preferential removal near braze joint are solved. The methods of reducing the residual stress of mirror are discussed. At last, some measurements and experiments are carried on, and the results conclude that the brazed SiC mirror can meet the requirement of large aperture optical systems
Study on the Solid Edge Banding Cracking of Panel Furniture
Authors: Zhou Cheng Min , Wu Zhi Hui , Ma Dan Dan
Published: September 2011

With the development of wood processing technology, panel furniture is getting more and more popular, where solid wood is often used for the edge banding to keep the natural wood grain, feel and colour. However, part of the panel furniture, especially that made in the south but sold to the north, has banding cracking issues due to various reasons. In this paper, on the base of comprehensive reference analysis and in-field exploration, the potential factors leading to banding cracking is studied; the influence of wood moisture content and adhesive on the cracking is specially analyzed; and the suggestions on the drying of the solid wood, glueing, manufacturing environment and process are presented. Thus, a new systematic concept to solve edge banding cracking is established, the study on which will be helpful to the development of panel furniture.
Optical and Electrical Properties of Some Organic Thin Films for Optoelectronic Applications
Authors: Chen S.B. , Zhong Zhi You
Published: September 2011

Organic semiconductor thin films of bis-(2-methyl-8-quinolinolato)-4-(phenyl-phenolato) -aluminium-(III) (BAlq), N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)benzidine (NPB), and tris-(8- hydroxyquinoline) aluminum (Alq) were prepared by the vacuum sublimation technique. The optical properties in the UV-visible region of the thin films were investigated by optical transmittance and absorbance spectra. The optical energy gaps were obtained from direct allowed transitions at room temperature by Tauc’s law. The Urbach energy and the slope of Urbach edge were estimated by the Urbach-edges method, respectively. Furthermore, the current-voltage characteristics of organic thin films were analyzed, and the different slopes in the lower and higher voltage regions were observed. From the experimental studies, the effective carrier mobility, free carrier density, and electrical conductivity were also evaluated respectively.
Study on FGH95 Superalloy Prepared by Spray Forming
Authors: Xu Yi , Qin Shu
Published: September 2011

FGH95 superalloy cylindrical billet was prepared by spray forming, The yield is 73.6%, porosity is 0.6%, the oxygen content is only 20ppm. Spray forming preparation method and technological parameter were illustrated. The microstructure on the different positions of billet were observed. The results show that the difference of γ′ phase size, feature and distribution depend on different cooling velocity and local temperature difference during the spray forming process. SEM of nonmetallic inclusions were observed, and XPS of nonmetallic inclusions, nozzle and adhesive were analysed, the results show that the nonmetallic inclusions were from nozzle and adhesive.
A Fluidity Study of Semi-Solid Rheo-Slurry of AC4C Aluminum Alloy in Gravity Sand Casting
Authors: Chucheep Thiensak , Canyook Rungsinee , Rattanochaikul Tanate , Janudom Somjai , Wisutmethangoon Sirikul , Wannasin Jessada
Published: September 2011

A new approach to evaluate fluidity of semi-solid rheo-slurries was developed. The equipment was designed in order to reduce pouring error by using bottom tapping and heated tapping ladle. Commercial AC4C aluminum alloy slurries were tested in spiral sand mold by gravity casting. The slurries were prepared by introducing fine gas bubbles into molten metal above the liquidus temperature at different rheocasting times. Average fluidity and microstructures of cast spirals were reported. Results show that the spiral microstructure is non-dendritic and the fluidity of AC4C alloy decreases with increasing solid fraction. In conclusion, the spiral casting method using bottom tapping can be used to evaluate the fluidity of rheocast slurries in gravity sand casting.
Tensile Properties and Microstructure of Butt Weld of Q235A Steel Made by Wet Welding Process
Authors: Zhang Hong Tao , Jiang Wen Jie , Feng Ji Cai , Zhong Shi Sheng
Published: September 2011

The effect of underwater wet welding processes with flux-cored wire on tensile properties and microstructure of Q235A steel was studied. Rolled plates of 8 mm thickness have been used as the base material for preparing single pass butt welded joints. OM and SEM were used to analyze the microstructure of the joint and the fractography of the tensile specimen. Tensile test showed that the fracure was occured at base metal and tensile strength could reach 415Mpa.
Anti-Extrusion Process in the Performance of Different Parameters on the Analysis of Metals
Authors: Zhao Han Dong , Zhang Hua , Sun Peng , Li Fei
Published: September 2011

This paper mainly introduces metal forming on extrusion simulations. Different process parameters of the simulation results are analyzed, such as ingots by billet pressure changes, change of temperature, metal flow speed of different process, and the metal performance changes caused by them are discussed.
Research on Key Technology of Ultra-High 3D Strengthening Heat Transfer in Plow Machining
Authors: Song Li Hua , Kang Jun Yuan
Published: September 2011

In accordance with the latest development direction in the filed of strengthening the heat transfer technology of strengthening the heat transfer on division of strengthening heat transfer by international authoritative Professor A.E. Bergle）, including 3D(three-dimensional) heat transfer of ultra-high performance improved in the fins of the design and analysis; 3D heat transfer strengthening of the plowing process mechanism the flexibility ,high speed and high precision of gathered tools and the realization of a 3D digital design and manufacturing . It also researches on the influential law of process parameters on the formation of the fin. It is shown that the whole fin-forming process can be classified into three stages：plowing，heaving and fins forming, and that the front angle，plowing depth and the plowing speed are the main factors influencing the fin forming. Moreover，within a certain range，the height of fin increases with the front angle and the plowing depth.
Novel Method to Strengthening of Polymer by Plane Compression Processing
Authors: Jiao Ming Li , Yang Kai , Liu Hong Yan , Zhang Wang Xi
Published: September 2011

An approach which formed sheet structure through plane compression processing in the bulk of polymer (polypropylene (PP)) was suggested and the strengthening mechanism was presented based on a series of experiment. The variety of super-molecular structure that the spherulite deformed into ellipse even fractures piece in the pressure field helped to increase the tensile performance. In the polar reign of spherulite, the lamellae underwent a slight deformation, and the lamellae broke into fraction and then slid each other along the flow direction in the equatorial region. Finally, the lamellae in the sample aligned along the flow direction, and the sheet structure which was packed each other by lamellae was built up by plane compression processing.
The Frontier Analysis of RCS for Micro-Nano Particle
Authors: Du Chang Hua , Li Zhen Kang , Liu Bin , Li Chun Tian
Published: September 2011

By the method of adding MNP (micron or nano particles) into general solder, the composite electronic solder can be prepared, due to its role of solution or dispersion strengthening, and can improve the thermostable fatigue and creep properties of solder joint, it is also usually named as RCS (reinforced composite solder).Based on researchful analysis of RCS, such as metal particles, particles for high hardness, particles for low expansion coefficient, rare-earth particles and low aggregated particle, and of their reinforced mechanism, the technical requirements of RCS is found, it is also analyzed problems and application prospects of RCS.
The Research on Lunar Soil Simulant Production System
Authors: Li Man , Tong Jing Yu , Wang Zhi Hao , Bai Yu , Tian Dong Bo , Wang Bin
Published: September 2011

Because the lunar soil is rarely, lunar soil simulant plays an important part in lunar exploration, development and utilization of lunar resources, to establish a lunar base research work. This paper presents a lunar soil simulant production system which is suitable for ground experiment of Lunar Exploration Project. The system consists of five parts: rough machining equipment, fine machining equipment, air classification equipment, mixing machine and pre-prepare equipment. The lunar soil simulant with different particle size produced by the equipments has the similar characteristics to the real lunar soil. This research has great significance on moon exploration and the lunar surface environment simulation.
Casting of a Wire Inserted Strip Using a Twin Roll Caster Equipped with Two Nozzles
Authors: Haga Toshio , Takahashi Kenta , Kumai Shinji , Warari Hisaki
Published: September 2011

Casting of a wire inserted strip was investigated using a downward melt drag twin roll caster. A nozzle was mounted to each roll. The wire was inserted between the lower and upper strip. Effect of use of two nozzles on the insertion of the wire was investigated. The insertion of the wire by the two nozzles was easier than one nozzle. The surfaces of the wire inserted strip cast using two nozzles was more sound than that cast using one nozzle. The position of the wire at thickness direction was almost center. When different aluminum alloys were poured from an upper nozzle and from a lower nozzle, a wire inserted clad strip could be cast.
Investigation on the Residual Stress Redistribution under Cyclic Loading
Authors: Yan Shao Hua , Zhu Zhong Yin , Ma Chuan Ping , Su Lei , Li Da , Chen Hui , Meng Li Chun
Published: September 2011

The residual stress,which is unavoidable in the process of flash-butt-weld rails,plays important roles in the service life of the railway rails.Residual stress can and do change in service.In this paper,the distribution of initial residual stress was presented,and the redistribution was measured after 2×106cycles as well.The result shows that residual stress would change after appling fatigue loading.After 2×106cycles,the residual stress of some tested places increased while others decreased,the state of the longitudinal residual stress in the side region and the foot region has not changed,which still presented compressive,while the change of the longitudinal residual stress in the head region and the foot region does not present general tendency. In the transverse direction,residual stress in the head and side head regions decreases while the foot region shows opposite change.
NOX and Soot Emissions Numerical Simulation of Diesel Engine Fueled with Biodiesel
Authors: Ge Jian Lin , Tang Dong , Chen Huan , Liu Sheng Ji
Published: September 2011

The three dimensional numerical simulation on NOX and soot emissions was carried out on 186 FA diesel engine fueled with pure diesel and B20 fuel using CFD software Fire v2008 and the generating rule and distribution of NOX and soot of two fuel was described. Through comparison of the measured indicator diagrams, it verified the accuracy of the model. Based on the simulation of the original diesel engine fueling with B20 fuel, the swirl ratio and injection advance angle are optimized and it proposes technical programs to reduce two kinds of emissions simultaneously, which is optimized of NOX and soot emissions, when the swirl ratio is 2.7 and injection advance angle is 352.5°.
Root Cause Analysis on Fracture of SN490B Steel Column-Diaphragm Joints Using Elector-Slag Welding
Authors: Lin Ker Chun , Jhuang Sheng Jhih , Liou Kuen Tai , Chang Heui Yung
Published: September 2011

Recently, the weld fractures of column-diaphragm joints were reported to disrupt the cyclic loading tests on steel welded beam-to-column connections in Taiwan. This paper analyzes the root cause leading to the weld fractures. To confirm the effects of electro slag welding (ESW), the hardness, toughness and microstructure are investigated for a SN490B steel column-diaphragm joint. The result shows that the ESW process may give the weld a relatively low hardness. In addition, the heat affected zone (HAZ) can absorb much less energy than the parent material. In detail, the 30-mm thick parent material absorbs energy more than 105J, satisfying the code requirement of 27J at 0oC in the Charpy impact tests. However, the welding heat causes the microstructure of HAZ to be notably coarse, reducing the Charpy value to 21 J. To prevent the weld fractures, it is recommended to refine the grain sizes of HAZ, improving the toughness. It is also suggested to develop and use the compatible welding materials.
A Design for FSS on Curved Band-Pass Radome
Authors: Cui Yao , Gao Xiao Guang , Hou Xin Yu
Published: September 2011

Frequency Selective Surfaces(FSS) are periodic array structure, generally, FSS are designed on plane structure. In this article, design of FSS for curved radome will be developed. the parameter of FSS, which have some frequency response, will be given through simulation and optimization, and FSS plane model will be manufactured. The parameter will be modified, based on the configuration of streamline radome , the arrangement of FSS will be designed on curved radome, finally, the FSS Radome will be manufactured. it is shown that FSS under this method is satisfied.
FEM Analysis of Solid Particle Erosion-Wear of 45 Steel
Authors: Lv Dong Li , Chen Ci Chang , Zhang Tao
Published: September 2011

Solid particle erosion-wear behavior under different working conditions was simulated by FEM. A three-dimensional finite element model of erosion-wear of solid particle was established, and Johnson-Cook material model and failure criterion were adopted to define the mechanical property of sample material. The process of spherical particle impacting 45 steel from different angles and under different impact velocity was simulated, respectively. Material deformation and strain condition were analyzed .The relationship between erosion-wear degree , impact angle and impact velocity was investigated. The results showed that, maximum plastic strain occurs on the surface of material when impacting from low angle and on subsurface while vertical impacting. The wear degree of material increases until reach the peak value at 40° and deformation volume increases with the vertical impact velocity，and there is significant accumulation of material around pit.
Failure Analysis of a Welded Aluminum Alloy Component in High-Speed Train
Authors: Zhu Yong Hui , Zhou Wei , Nie Yuan , Zhu Zhong Yin , Chen Hui , Wang Gui Guo , Yu Jin Peng
Published: September 2011

In this paper, a failure analysis is made to a welded aluminum alloy component of the equipment by module below the high-speed train. Making force analysis to the welded components by finite element, microscopic morphology observation and element distribution measurement of the fracture surface are done by the scanning electron microscopy and spectroscopy .It is determined that the main reason of fracture of welded components was that stress concentration exist in the working conditions, and the weld toe is the most severe stress concentration region. The stress concentration causes the fatigue microcrack, and under the action of repeated external force crack propagates and then crack. Lacking of penetration sites is under tensile residual stress, the crack propagation speed, and soon to instability and then broken.
Fatigue Crack Behavior of Welds in Q460NH Steel
Authors: Jia Kun Ning
Published: September 2011

The fatigue crack growth behavior of weld joint of Q460NH steel is very important for estimating life-time in terms of a crack length in weld joint. In this paper , fatigue crack growth behavior of weld metal (WM),heat affected zone(HAZ) and mother metal(BM) have been researched at room temperature. The variation of fatigue crack growth rate(da/dN) with stress intensity factor range (ΔK) for WM, HAZ and BM is discussed within the Paris region. It is shown that fatigue crack growth rate of WM is the slowest in tree parts .
Influence of Microstructure of TC11 Titanium Alloy on Ultrasonic Velocity and Attenuation
Authors: Ai Yun Long , Liu Li , He Wen , Liang Bing Liang , Xu Ji Lin
Published: September 2011

TC11 titanium alloy (Ti-6Al-3Mo-1.2Zr-0.3Si) was subjected to solution treatment above β-phase field solution for 1 h with different cooling rates, such as water quenching, oil quenching, air cooling and furnace cooling, and gained four different microstructures. The relationship between microstructures and ultrasonic parameters such as ultrasonic longitudinal wave velocities (ν) and attenuation coefficients (α) was investigated. The results show that ultrasonic longitudinal velocities and attenuation coefficients increase with reducing the cooling rate from water quenching to furnace cooling. The hardness of these microstructures exhibits an opposite behavior to longitudinal wave velocity and ultrasonic attenuation coefficient.
A Study on Strain Properties of Bamboo in Process of Heating and Cooling
Authors: Han Jian , Zou Yue
Published: September 2011

Strain of bamboo affects remakably bamboo products. This study, through measuring strain of bamboo with the resistance strain measuring instrument, studied the radial and tangential strains of different height and sections of moso bamboo. The study indicated that the tangential strain of bamboo appeared mainly parabolic curve form, and the strain increased gradually from outside to inside part of bamboo wall in process of heating. The radial strain of bamboo increased gentlely with the temperature rising before 100°C, then rapidly increased after 100°C. The radial strain of bamboo increased gradually from upside to bottom of bamboo pole with the temperature rising too. The tangential strain of bamboo increased gentlely from 150°C to100°C, then rapidly increased from 100°C to 30°C in process of cooling, but radial strains at different height of bamboo pole presented mainly linear change with the temperature falling in process of cooling.
Scientific Analysis of an Ancient Bronze Mirror Dating of Han Dynasty
Authors: Sun Hong Fei , Niu Zhan Rui , Wang Can Ming , Yuan Bo
Published: September 2011

A bronze mirror dating of Han-dynasty was studied in this paper. The in-depth structure and the composition of the natural patina and substrate alloy were determined by Electron probe micro-analyzer (EPMA) observation and EDS cartographies on a cross-section, the mineral composition of patinas were analyzed using XRD. The results show the layer structure of the patina has two obvious layers, and the inner layer ranges from 90µm to 260µm. This bronze mirror is a typical ancient Chinese black mirror Heiqigu, and the formation of high tin layer is due to special surface treatment by the ancients. Tthe composition of the patinas on the mirror and that of substrate alloy were found to be highly heterogeneous, the thin black patina on the mirror containing is cassiterite.
Material Characterization and Modeling of High Strength PM Steel
Authors: Mirajkar Sachin B , Gopinath K. , Prakash Raghu V.
Published: September 2011

Powder Metallurgy (PM) component properties are influenced by the pore morphology, size, size-distribution and pore content [1]. Structural alloy Astaloy LH mechanical properties are characterized for density range 6.3 to 7.1 g/cm3. Porosity characterization of the material is also done using ASTM standard. In the first phase, an attempt is made to predict the tensile property using Gurson-Tvergaard-Needleman (GTN) model and FEM. The prediction is verified with tensile test results. It is observed that after fine tuning the parameters in the model, the prediction is found to be close to experimental values.
The Conception Design of Flower-Shaped Seat in Park Landscape
Authors: Ding Wen Jiao , Yang Li Fang , Zhao Yue
Published: September 2011

KeyWords: parks; landscape research; design of seats; bionics design Abstract: Landscape is an important ingredient of city parks, so the design of seats in the parks integrated with the city landscape serves as an innovative inspiration for the design of the specific product. With the research of the landscape design and park seats, this project proposes flower as the developing form of the park seats, with the lily as the final design choice for a new seat in the parks. The specific structural forms of the seats are designed in accordance with the characteristics of lily, and the materials for the seats are chosen based on the park seats and bionics design. An integration of landscape and bionics in this design brings an innovation for the design of the landscape and seats in the parks.
A Hafnium Material Control Rod Design and Manufacture
Authors: Huang Hong Wen , Mi Xiang Miao , Qian Da Zhi , Xu Xian Qi , Zhang Zhi Hua
Published: September 2011

Because the metallic hafnium has good combination properties, that makes it the preferred material for control rods of nuclear reactors. To prevent the irradiation deformation and the mechanical property decrease of hafnium plates, and to increase the service life of the control rods, a new type of square-tube control rod is developed. The elemental composition, mechanical property, the corrosion resistance and the physical characteristics of hafnium are researched. Several tests are carried out after the product manufactured, which prove that the design and manufacture of the control rod meet the requirement of the technical conditions.
Design for Remanufacturing and Remanufacturability Based on Process
Authors: Yao Ju Kun , Zhu Sheng , Cui Pei Zhi
Published: September 2011

Design for remanufacturing is an important content of remanufacturing engineering, and the remanufacturability of product is mainly determined in the stage of product design. Through developing study of product design for remanufacturing, it can promote the remanufacturability, and markedly enhance the efficiency of remanufacturing production. This paper give some relative concepts about product design for remanufacturing and remanufacturability based on total remanufacturing process, such as remanufacturability, and bring forward the remanufacturability research contents and qualitative design principals in the product design stage.
Design of Novel Beam Demagnifier Based on Total Reflection -Refraction
Authors: Qin Hua , Sun Cun Zhi
Published: September 2011

A novel beam demagnifier(a cone) is presented based on total internal reflection-refraction principle, and the light propagation characteristics inside the cone were studied by using ray-tracing method and computer simulation. This paper presents several proof-theoretic results concerning a cone as a beam demagnifier under certain conditions. When the semiapex angle of the cone is equal to a series of specific values an output beam is parallel to an incident beam, the beam's diameter narrows, and the demagnification ratio of the cone is a function of apex angle and there exists a series of extreme points; the demagnifier can be used in series so as to further narrow or magnify the diameter of incident beam.
A New Mesh Variables Mapping Method for Vehicle Crash Simulation with Considering Sheet Forming Effects
Authors: Li Zhou , Yang Xu Jing
Published: September 2011

In finite element analysis for vehicle body components, there are different meshes between sheet metal forming and crashworthiness analysis. In order to transfer mesh variables between different mesh models, a new mapping method for mesh variables is proposed in this study based on an inverse isoparametric mapping. In this method, the mesh variables, such as thickness distribution, stress and strain, are mapped by accurately positioning crash model’s nodes to transfer data from the sheet metal forming model to crash model. As an example, this approach was applied to the crash simulation analysis for a vehicle front bumper bar. The results showed that this method allows to precisely transfer mesh variables from sheet metal forming analysis to crash simulation analysis with considering the forming effects. The efficiency and accuracy are thus improved for vehicle crash simulation with this approach.
Solver for Finite Element Analysis of Ring Rolling Process
Authors: Zhang Xue Bin , Wan Qiong , Li Zhi Gang
Published: September 2011

A dynamic explicit finite element solver is developed for numerical simulation of metal ring rolling process, which is a complex process of material nonlinearity, geometric nonlinearity and contact nonlinearity. An elastro-plastic dynamic explicit finite element equation and central difference algorithm are used. To control hourglass, a stable matrix hourglass control method is used to ensure energy balance in the simulation. Two-step method of global search and local search is used to reduce the contact judging time. In the elastic-plastic stress updating, tangent forecasting and radical return algorithm are used to eliminate the stress deviate from the yield surface. The accuracy and stability of the solver is verified by comparison of two ring rolling processes with the experimental results.