bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization of Process Parameters for Injection Molding Based on Taguchi Technique
Authors: Fu Shi Jun
Published: June 2012

In this paper, Taguchi and CAE technique are combined to study the influence of process conditions on the warpage of injection molding parts through twice orthogonal design experiments, and the injection process parameters are optimized according to the warpage. For the parameters selected, melt temperature and packing pressure have effects on the warpage of injection molding parts are highly significant, injection time is significant, other parameters have little effects. Within the range of experiments, the warpage decreased with the rise of the melt temperature and packing pressure. At last, the optimum process parameters of injection are that the mold temperature is 60°C, packing time is 10s, melt temperature is240°C, packing pressure is 115MPa and injection time is 0.4s.
Experimental Study on the Influence of Single-Pass Deformation on Recrystallization Behavior and Microstructure
Authors: Liu Yu Yan , Hu Sheng , Chen Lin
Published: June 2012

By using Gleeble1500-D thermal simulation machine, Rare Earth(RE) adding Q345B steel of single-pass compression test were carried out. A study had been made of the effect of different deformed conditions in hot rolling process on Nd-modified Q345B steel recrystallization behavior and microstructure evolution.The result shows that RE steel Q345B of single compression test are consistent with the general experimental rule. Rare Earth additions significantly increased hot- deformed resistance at low temperature compression, however, it is not obvious at high temperature. The increased hot-deformed resistance and the degree of the retardation is more obvious for heavy RE Tb than light RE Nd.
Experimental Investigations on Electromagnetically Assisted Corner-Fill Performance of AA5052 Sheets
Authors: Liu Da Hai , Li Jun Chu , Chang Chun
Published: June 2012

To establish the efficacy of electromagnetically assisted sheet metal stamping (EMAS), the corner-fill ability of AA5052 sheets specified in conventional deep drawing was experimentally demonstrated and evaluated within a two-step EMAS process. First, conventional axisymmetric deep drawing was conducted to make a cylindrical cup with a rough-shaped bottom corner. The second step utilized a shaped coil to force the pre-formed cup into the die cavity, and the related electromagnetically assisted corner-fill performance was investigated. Experimental results show that the ideal of hybrid stamping-EMF sequence can successfully solve the formability problem involved in conventional stamping. During electromagnetically assisted corner-fill process, the deformation dispersion effect of dynamic phenomenon works remarkably on the fully deformed sheets, which will inhibit local instability of deformation and thus enhance materials formability.
Warpage Analysis of Injection Molding Based on Mold Flow
Authors: Yang Jun Kai , Xu Yun Jie
Published: June 2012

The most common issue in injection molding is warpage of work pieces. Copier parts are taken as the example. The mold flow software is used to analyze and solve defects of such parts, and the optimal mold structure can be obtained so as to save costs and improve product quality and efficiency.
Influence of Sputtering Pressure for Radio Frequency Magnetron Sputtering (103) Oriented AlN Films on (100) Silicon Substrate
Authors: Jhong Shih Bin , Wu Sean , Lee Maw Shung
Published: June 2012

The thin film of (103)-oriented aluminum nitride (AlN) is an attractive piezoelectric material for the applications in film bulk acoustic wave resonator (FBAR) devices. Due to the bulk acoustic wave (BAW) properties of (103) oriented AlN films, it can excite a quasi-shear mode (velocity = 5,957 m/s, K2 = 3.8%) that can be used for FBAR liquid sensor and even loss less than the FBAR device with (002) oriented AlN films. In this research, the (103) oriented AlN films were successfully deposited onto (100) silicon substrate by radio frequency (RF) magnetron sputtering. Different sputtering pressures (1m torr, 3m torr, 5m torr, and 7m torr) were discussed in this experiment process. Comparisons were made on their crystalline structures with X-ray diffraction (XRD) and the surface morphologies was investigated by the atomic force microscopy (AFM). The result exhibited the optimal sputtering pressure is 5m torr. The optimal (103) oriented AlN films have the strongest XRD intensity, the smallest full width at half maximum (FWHM) value (0.6°), the largest grain size (15.78nm) and the smooth surface roughness (Ra=3.259nm).
Microstructuring of Polystyrene Films by Template-Leaching Technique
Authors: Xue Meng Meng , Li Guang Fen
Published: June 2012

In this study, porous polystyrene membranes were prepared by a template-leaching technique. A suspension was first prepared by dispersing both polystyrene and starch in toluene, in which starch was used as leachable component. The weight ratio of starch/polystyrene ranged from 1:1, 1:2 to 1:3, whereas the concentration of the suspensions altered from 1%, 3%, to 5% by weight of polystyrene/toluene. After spin-coating the prepared suspension on the glass substrate, polystyrene/starch thin-film was produced, and then was treated with inorganic acid to remove starch components. The porous films with ordered and homogeneous structures were resulted. Analysis by contact angle measurement, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy analysis (FTIR) show that the microstructures on the porous films were affected by many experimental factors during the formation of thin-film and the following leaching process. Especially the type of the inorganic acid such as HCl, H2SO4, or HNO3, and the concentration of the specific acid selected in the leaching process have dramatic influences on the formation of the porous polystyrene membrane. The results further demonstrated that starch particles can be maximally removed when the films were immersed into the aqueous solution of HNO3.
Study of Microstructure and Texture of Nb-IF High Strength Steel after Cold Rolling and Annealing
Authors: Hou Zi Yong , Xu Yun Bo , Wu Di , Wang Guo Dong
Published: June 2012

The effects of annealing routes (batch annealing and continuous annealing) on the development of microstructure and texture in a cold-rolled Nb-IF high strength steel sheet were studied by means of optical microscopy(OM), electron backscattered diffraction(EBSD) and ODF analysis. The results show that the finer and more homogenous recrystallization grain can be observed in the CA steel. The CA process leads to an increase in the intensity of the γ-fibers, and the very sharp and uniform γ-fibers are found in this case, which is beneficial to the deep-drawability.
Design of Drawing Straightening Machine for Roll-Forming of U-Shaped Steel
Authors: Wang Hui Feng , Han Jing Tao , Liu Jing , Zhang Yong Jun
Published: June 2012

The cold-roll-formed profiles usually defects such as bow, camber, twist, edge wave, corner buckling as well as edge cracking, and splitting. Straightening is used as the later part of working procedure in order to eliminate these defects and improve the quality of the final profile. A drawing straightening machine is designed to achieve the purposes of the U-shaped steel straightening. In the design coefficient of friction, forming speed, roll speed, methods to minimize defects.
The Influence of Injection Processing on the Shrinkage Variation and Dimensional Stability of Wax Pattern in Investment Casting
Authors: Wang Dong Hong , He Bo , Li Fei , Sun Bao De
Published: June 2012

The accuracy of the wax patterns used in the investment casting process has a direct bearing on the accuracy of the final cast part. Wax injection process plays a key role in production of nearly net shape wax pattern. Dimension shrinkage is one of the most significant problems of a wax pattern in terms of dimensional stability in the wax injection molding. This study aimed to determine the effects of injection parameters on the dimensional accuracy of the wax patterns. Linear contractions normal to flow direction and weight of wax patterns were measured and dimensional variations were evaluated. The results highlight it is important that when dealing with thick gates, short packing time appears to be the best way to avoid gate area over packing and dimensional variations, high packing pressure appears to increase expansion and dimensional variation of wax pattern.
Industrial Application of the Packaged Soft-Reduction Technology for Slab Continuous Casting
Authors: Feng Ke , Han Zhi Wei , Cao Jian Feng , Kong Yi Wen , Wang Shui Gen
Published: June 2012

Based on the conception of integration and optimization of process, mechanical, electric and hydraulic system, the advanced CISDI packaged soft-reduction technology for slab continuous casting with our full intellectual property rights has been developed successfully, which consists of the metallurgical process models with strong function and advanced arithmetic, the segment equipments with optimized structure and high strength, the basic automation program with full inspection and control function, the reliable stable hydraulic system and automatic system. It contains two control modules, viz., the static soft-reduction function & dynamic soft-reduction function, and three gap-adjustment modes, viz., the position-control mode, pressure-control mode & soft-clamping mode. From the opinions of equipment protection and production safety, some functional mechanism such as segment ordinal action, gap self-adapting adjustment, forced protection for breakout prediction, and etc., have been adopted. The whole system has been put into the industrial practice on the No.6 slab caster of Liusteel China, which has shown the smooth caster operation, the steady running of system, and the good metallurgical effects on improvement of internal quality of slab like center segregation and center porosity. The industrial application of CISDI soft-reduction technology has brought the rising of output proportion of high-class steel grades and the increasing of qualified rate for slab quality inspection, which has resulted in the distinct economic benefits for Liusteel group.
The Analysis of Grinding and Polishing for the Tile Planetary Disc Griding Machine
Authors: Dai Zhe Min , Li De Sheng
Published: June 2012

In this study, the polishing machine’s mathematical model of the movement has been established by analysis the several polishing machines’ grinding and polishing process for tile. Then according to the model to simulate the trajectory and compare the grinding grain uniformity and the size of the grinding area. The results show that the disc grinding machine in improving of the efficiency of grinding and grinding grain uniformity is better than the other motions.
Carbon Nitride Films Prepared by PECVD in CH4-NH3 Precursor
Authors: Ni Jing , Hao Xi Ping
Published: June 2012

Carbon nitride (CNx) films were fabricated by plasma enhanced chemical vapor deposition technology in methane-ammonia system, in which the plasma was excited by the hollow cathode glow discharge. The composition，microstructure and hardness of the deposited films were investigated by measurements employing X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and nano-indentation experiment. The results indicate that the nitrogen content in the film varies from 4.2 to 8.6 at.% and the nitrogen atoms are bonded to carbon atoms through C-N, C=N and C≡N bonds. Furthmore, higher nitrogen content is in favor of the formation of C-N bond, which may enhance the film hardness.
Study on Tool Life of Surface Textured Tool in Dry Cutting of Ti-6Al-4V Alloys
Authors: Wu Ze , Deng Jian Xin , Zhao Jun
Published: June 2012

Surface textured tools were fabricated by laser beam machining. Dry cutting of Ti-6Al-4V alloys was carried out with these surface textured tools and conventional tools for comparison. The cutting temperature, tool flank wear and surface roughness of processed workpiece were measured. The experimental formulas of tool life based on DOT method were developed. Results show that the surface textured tool can reduce the surface roughness of workpiece, and the tool life of surface textured tool is improved by 15% or so compared with the conventional one.
Flow Behavior and Workability of a Zn-8Cu-0.2Cr Alloy during Hot Deformation
Authors: Guo Sheng Li , Du Peng , Wu Xiao Ping , Li De Fu
Published: June 2012

The hot deformation behavior of Zn91.8-Cu8-Cr0.2 (in wt.%) was investigated by means of hot compression tests in the temperature range of 230-380 °C and strain rate range of 0.01 - 10 s-1. The constitutive equation and processing maps were developed. The influence of strain on the flow stress was studied by considering the effect of the strain on material constants. The stress-strain curves obtained by the constitutive equation are in good agreement with experimental results. The proposed constitutive equations can be used for the analysis problem of hot forming processes. The processing maps have exhibited a domain, which is optimum processing window for hot working, in the temperature range of 310 - 380 °C and strain rate range of 0.01-1 s-1 corresponding to the higher efficiency of power dissipation. The large regime of flow instability is observed at high strain rate. The instability regime should be avoided during hot deformation processing.
Grain Refinement of LC9 Alloy by Low-Power Ultrasonic Vibration Melt Treatment
Authors: Chen Le Ping , Han Yan Yan , Zhou Quan
Published: June 2012

The influences of different preheating temperature of mold and treatment temperature on solidified structure of LC9 alloy were studied by low-power ultrasonic vibration melt-treatment. The results show that grain of LC9 alloy can be refined greatly by low-power ultrasonic vibration melt-treatment. The dendrite growth is restrained and the microstructure is changed from larger dendrite grains to dominant fine none-dendritic and globular grains. With the decrease of preheating temperature of mold, grain size decreases. The efficiency of grain refinement is better at low preheating temperature. With the increase of ultrasonic vibration temperature, grain size decreases firstly, then increases, and the turning point is 660 °C. At 640 °C, grain size of the alloy with US vibration treatment changes slightly compared with non US-treated alloy.
Research and Development of Special Machine for Drilling and Milling Compressor Piston
Authors: Xu Wen Qin , Zhou Bai Qing , Sun Yin Da
Published: June 2012

The paper introduces an improvement in technology of processing piston of air conditioning compressor in automobile, and methods of designing, manufacturing, and testing a special machine by which the processing quality and efficiency are enhanced.
Preparation of the Reed Cellulose Membrane by Using NMMO Method
Authors: Pan Mei Ling , Li Wen Jiang , Wang Ming Rui , You Chen
Published: June 2012

The reed cellulose was extracted from the wild reed in the hot 12% sodium hydroxide (NaOH) aqueous solution. Then, the cellulose membrane was successfully prepared by using the reed cellulose as the raw materials dissolved in the solvent of N-methylmorpholine-N-oxide (NMMO). The characterization of the reed cellulose film was studied by the digital camera, optical microscope and scanning electron microscope (SEM). The results revealed that the reed cellulose membrane is a smooth appearance and good quality film, which could have many applications in the practical filed.
Processing Method of Leaves Used in Thermal Insulation Building Materials
Authors: Jiang De Min , Cui Su Ping
Published: June 2012

This paper makes a study of processing methods of several types of fallen leaves, and exploration of ways of collecting, storing, drying, crushing, and screening of leaves, involving a study of the rate of water loss of leaves in the drying process at different temperatures, and a comparison of crushers to be chosen in the crushing process of the leaves so as to provide a reasonable basis for the development and application of the leaves in the field of building materials.
Research on the Process Parameters for High-Speed Cutting
Authors: Gao Dong Qiang , Lin Huan , Li Zhong Yan , Yi Jiang Miao
Published: June 2012

In this paper, it is analyzes process parameters’ influence on the chip deformation, tool life, machined surface quality and the stability of cutting systems in high speed machining. It provides important reference of the choice of cutting parameters for high-speed machining user.
An Experimental Study on the Tribological Performance of Tool Materials in Micro-Cutting 1Cr18Ni9Ti
Authors: Fang Ze Ping , Wang Xi Bin , Liu Zhi Bing
Published: June 2012

Considering the tribological characteristics of the micro-cutting, an approach that divided the micro-cutting area into four parts based on the contact stress and speed was proposed to the friction performance research. Friction tests under different conditions were carried out on a UMT3 tribometer and a special tribometer assembled based on HAWK TC-150 turning lathe. The morphological analyses of the worn surface were made by optical microscope and scanning electron microscope. The experimental results indicated that different rubbing pairs had different friction properties under different speeds or loads; for stainless steel, high speed steel showed a better friction performance in low speed and load, while cemented carbide has more advantages in high speed or high load. Hence, a suitable choice principle was proposed for the micro-cutting tool material based on the tribological characteristic.
Design of Five-aixs CNC System for Electric Discharge Grinding (EDG) Polycrystalline Diamond (PCD) Tools
Authors: Shi Shao Hua , Ye Pei Qing , Fang Chen Xi
Published: June 2012

Polycrystalline Diamond (PCD) tools are widely used while machining wood-based composites because of its outstanding hardness, thermal conductivity and abrasive resistance. However, the above mentioned beneficial properties such as super hardness also cause problems in manufacturing PCD tools using traditional process methods. The main problem now in manufacturing PCD tools is the low efficiency and difficulties while manufacturing PCD tools with complex curved surface. To manufacture PCD tools with complex curved surface more efficiently, in this paper, the mechanical structure, hardware circuit and software system of five-axis EDG CNC system are introduced. To satisfy the unique requirements of EDG, a proper mechanical structure of 5 CNC controlled axis and 2 manual axis are given, as well as the design of hardware circuit of EDG based on PCI Bus. The software system which is designed based on RT-Linux is divided into four modules: real-time cyclical tasks module, real-time gusty tasks module, non real-time tasks module and EDG process database. , This paper gives out the solutions of the specific functions of this special CNC system, including automatic measurement, automatic programming, automatic electrode wear compensation, and detection and control of spark gap. The detailed structure and organization of the software system is also provided. At last, through actual cutting experiments of woodworking PCD tools, the correctness and practicality of this system is verified.
The Structure and Frictional Properties of Aluminum Alloy Anodic Oxide Film
Authors: Chen Sui Yuan , Yang Yong Ze , Liang Jing , Liu Chang Sheng
Published: June 2012

Anodic oxide films were prepared firstly on the surface of a 2024 aluminum alloy. Then the effect of different heat-treatment temperatures on the structure and properties of the films was studied. The results indicate that the construction units of Al2O3 oxide film were composed of tubules less than 100nm in external diameter, and the film became more compact and uniform as a result of the increased temperature after the heat treatments of 100, 150, 200, 250, 300, 350, and 400°C under the protection of a H2 atmosphere. The hardness of the films increased linearly with the increase of heat treatment temperature; whereas the wear loss tended to decrease first and then increase. After being treated at the temperature of 250°C, the hardness reaches 606HV, the wear loss is a minimum of 11mg. The structure of the film heat-treated at 250°C has a compact structure, higher hardness, and the best wear resistance.
Study of NC Electrochemical-Mechanical Composed Cutting on GH710
Authors: Jia Wei Ping , Miao Bin , Wu Meng Hua
Published: June 2012

The technology of the NC electrochemical-mechanical composed cutting was used on cutting the GH710 alloy materials, and orthogonal experiment had been done to analyze the effects of parameters on cutting depth. The results show that the spindle speed and voltage are mainly two factors to affect cutting depth of the workpiece. Moreover, the results also identify the optimal machining parameters: Temperature of 45°C, Voltage 24V, Electrolyte pressure1.2MPa and Spindle speed1000 r/min.
Cutting Efficiency by Drilling with Tools from Different Materials
Authors: Mrkvica Ivan , Janoš Miroslav , Sysel Petr
Published: June 2012

Development of cutting tools is basic condition for rationalization of process cutting because it goes out from need of processing new constructional materials. From view of tool it takes application progressive cutting materials. Cutting tools so relevantly make for accomplishment main demand on methods of cutting; it is provision of high productivity production and attainment of desideration of finish surface. It is known, that cutting property of cutting tool is influence by many factors.
Monitoring and Prediction of Surface Roughness in Ball End Milling with Air Blow Application
Authors: Tangjitsitcharoen Somkiat , Ratanakuakangwan Suthas
Published: June 2012

This paper presents the additional work of the previous research in order to investigate the relations of the cutting conditions and the various air blow applications which affect the surface roughness. The suitable cutting condition is determined for the aluminum (Al6063) with the ball end milling by utilizing the response surface analysis referring to the minimum surface roughness. The cutting force is monitored during the cutting to analyze the surface roughness. The dynamometer is employed and installed on the table of 5-axis CNC maching center to measure the in-process cutting force. The models of surface roughness and cutting force are calculated by using the multiple regression analysis with the least squared method at 95% significant level. The experimentally obtained results showed that the surface roughness can be well explained by the in-process cutting force. The prediction accuracy and the prediction interval have been presented to verify the obtained surface roughness model at 95% confident level.
The Anti-Oxidation Properties of MoS2/Sb2O3 Films
Authors: Zhang Yan Shuai , Zhou Hui , Wan Zhi Hua , Zheng Jun , Sang Rui Peng , Yang La Mao Cao
Published: June 2012

The MoS2/Sb2O3 films were prepared by RF magnetron sputtering. The films were stored in humid environment (25°C, 60%RH) 30 days. The anti-oxidation properties of MoS2/Sb2O3 were studied by XPS. The composition was studied by XRF. The results show that the anti-oxidation properties were improved by doping Sb2O3. Introducing Sb2O3 into the films provides a substantial benefit to tribology properties of film.
Optimization of Sanding Parameters for Wood Surface of Plantation-Mytilaria laosensis
Authors: Su Chu Wang , Huang Jing Da , Luo Jian Ju , Lai Lian , Wuang Yuan Yi
Published: June 2012

In order to analyze the relation between wood surface roughness of plantation-Mytilaria laosensis and sanding parameters, two orthogonal experiment were performed. The results show that the mesh of the sandpaper has remarkable influence on wood surface roughness of plantation-Mytilaria laosensis,but the feeding speed and sanding thickness don’t; when the mesh of the sandpaper is 150, the feeding speed is 7 m/min and sanding thickness is 0.6 mm during the first sanding and the mesh of the sandpaper is 240, the feeding speed is 8m/min and sanding thickness is 0.15mm during the second sanding, the smallest roughness (Ra) was obtained as 2.79μm. Considering production efficiency, changing feeding speed into 9 m/min in the theory optimization scheme, engineering optimization scheme was obtained, and the wood surface roughness (Ra) is 2.80μm.
Research on Curved Surface Forming of Nomex Honeycomb Material Based on Ultrasonic NC Cutting
Authors: Hu Xiao Ping , Chen Sen Yan , Zhang Zhi Chuang
Published: June 2012

This article introduced the Nomex honeycomb composite material, analyzed the insufficient of the traditional milling process in Nomex honeycomb composite processing, and proposed using the characteristics of ultrasonic cutting combined with NC technology to process the honeycomb composites. It analyzed the forming principle of the corresponding curved surface according to the special ultrasonic cutting tool and cutting method, and established a corresponding error.
The Application of Ultrasonic Technology in the Hard, Brittle Materials Processing Research
Authors: Zhang Lian Zhong , Li Jing Min
Published: June 2012

The ultrasonic processing to sometimes also call that a Ultrasonic machining, it can not only processing cemented carbide, hardened steel, and other hard-brittle metal materials, and better Co-processing in glass, ceramics, germanium semiconductor, marble, a non-conducting silicon, and other hard-brittle non-metallic materials, but also can be used in cleaning, welding, testing, measurement, metallurgy and other aspects of this paper to study the principles of ultrasonic processing and The application of ultrasound to explore Development, the modern processing technology of the latest trends.
Research and Evaluation on the Machining Properties of Picea spp.
Authors: Su Chu Wang , Wang Ze Kun , Hu Li Wei , Huang Jing Da , Li Qi Jian
Published: June 2012

In this paper, the machining properties of Picea spp., compared with Castanopsis hystrix, were tested. Their properties were conducted according to the criteria ASTM D1666-87 and the test on crosscutting is referred to the method established by New Zealand Forest Research Institute. The results show as follow: The machining properties of Picea spp. and Castanopsis hystrix show excellent in the planning, sanding, boring, shaping and crosscutting, but in the mortising properties, Picea spp. which was a bit poor shows fair and Castanopsis hystrix shows good. The properties of Picea spp. were in an all-round way better than Castanopsis hystrix. In the machining performance comprehensive evaluation system for full marks 50 points, their comprehensive marks were separately 45.5 points and 44.4 points.
An Automatic Welding System for Mini-Van Dashboard Trestle
Authors: Wei Jian Jun , Fan Peng Cheng
Published: June 2012

An automatic welding system based on playback robot is introduced. The composition and characteristics of the system, together with the application results of prototype, are provided. Compared with manual welding, its product quality is better and more consistent, production efficiency is about 4 times higher.
Numberical Simulation of Welding Deformation under Different Conditions
Authors: Yang Qing , Xie Shu Jun , Gao Hai Tao
Published: June 2012

To simulate the welding and heat treatment process of the Q345 plate with V-groove, Finite element software ANSYS was employed. A reasonable three-dimensional solid model was set up by using element birth and death technology to simulate the formation of the weld. Constraint was applied on both sides of the base metal in the welding and cooling process. Then constraint was removed when the specimen was cooled to room temperature, the angular distortion of welding increases by 75.03% after the constraint is removed. Then heat treatment was conducted on the plate of which the constraint was removed. The deformation results show that after heat treatment the angular distortion is reduced to 30.37% of the value before heat treatment.
Static Characteristics of Air Bearing Film with the Linear Accommodation Coefficients in HDDs
Authors: Yu Hui , Shi B.J. , Ji Jia Dong
Published: June 2012

Based on various combinations of ACs of the slider and disk, the influence of ACs, were investigated by researchers. In the present paper, the static characteristics of air bearing film with the linear ACs are investigated. Pressure distribution and shear stress distribution are obtained by solving the free molecular MGL equation numerically by a mesh-free method, called Least square finite difference (LSFD). The simulation results show that with different ACs the shear stress and pressure are different, and on shear stress the influence of AC of slider is more obvious than that of disk in close to disk read-and-write head.
Molecular Dynamics Study on Formation of Carbon Nanotube X-Shaped Junction by Heat Welding
Authors: Yang Xue Ming , Chen Dong Ci
Published: June 2012

Molecular dynamics simulations are used to investigate the junction formation of two crossed single-walled carbon nanotubes (SWCNTs) with or without preexisting structural defects by heat welding. The junction formation of the chiral SWCNTs by heat welding is discussed. Furthermore, both the single vacancy defects and double vacancy defects are introduced in SWCNTs to explore the effect on junction formation by heat welding. We found the single vacancy defects and double vacancy defects pairs distributed on both crossed SWCNTs will accelerate the heat welding process and make the junction easier, and the required temperature for junction formation will be significantly reduced.
Study of Titanium Foil Welding Using Micro-Plasma Arc Welding
Authors: Wang Fu Xin , He Jian Ping , Fang Jia Qiang , Xiang Feng , Ren Lei Lei
Published: June 2012

Ultra-thin Titanium foil, which is widely used in manufacture of thin-walled titanium tubes, automobile parts, medical and other industrial fields, is an excellent structural material. Micro-plasma arc welding system which was developed independently by Shanghai University of Engineering Science was used in the experiments of welding Titanium foil 0.05mm thick. Welding experiments were carried out with matching parameters including welding current type, welding current value, pulse frequency, ratio of peak value and base value of pulse current, amount of lap and the other welding process parameters set constant, achieved one side welding both sides formation and got good welding formation. Based on these experiments, influences on welding quality induced by those factors are analyzed.
Experimental Study on Ultra-High Cycle Fatigue Property of Q345 Welded Joint
Authors: Zhao Xiao , Zhao Jian Jun
Published: June 2012

The present paper deals with experimental studies on the ultra-high cycle fatigue property of Q345 bridge steel. Using the ultrasonic fatigue testing technique, specimens of Q345 welded joint with hourglass shape were designed using an analytical method combining with the finite element method and then fatigue tested in air at room temperature under fully reversed cyclic loading conditions (R=-1). The results show that the S-N curves of welded joints and relative base material specimens show continuously decreasing tendency in the very high cycle regime (105-109 cycles). Fatigue property of welded joint is much lower than that of base material and the fatigue strength of welded joint is only 45.0% of base material. Fracture can still occur on welded joints beyond 5 106 cycles, which indicates the fatigue limit defined at lifetime of 5 106 cycles cannot guarantee a safe design.
Visual Sensing System for Thin Plate Welding Based on Rotund Facular Laser
Authors: Gu Wang Ping , Xiong Zhen Yu , Liu Pin
Published: June 2012

In order to solve the problem of thin plate butt-welded tracking, a welding vision sensing system with a rotund facular laser has been designed. In the vision sense system, each parameter of the interior part has been designed by a variety of experiments. The designed image processing software can precisely identify the position of the joint, based on the optimal designed vision sensor system. The thin plate butt welding experiments have been taken with the designed sensing device. The experimental results show that the vision sensor system with a suitable auxiliary illuminant can obtain satisfying visual image information in stainless thin plate butt-welded.
Numerical Simulation of Influences of Preheating and Postweld Heat Treatment in Welding
Authors: Yang Qing , Xie Shu Jun , Yu Tian Bao
Published: June 2012

In this paper, to investigative effects of preheating and postweld heat treatment on residual stress field in Q345 steel pipe welding, the finite element model was established. Preheating processes and postweld heat treatment process were simulated respectively. The results show that preheating can homogenize residual stress distribution of the weldment and decrease the residual stress. The heat treatment reduces the residual stress in inner and outer walls by 40% and 60% respectively and the stress distribution is more even and the stress concentration is reduced.
Study on a Kind of White Massive Microstructure in P91 Steel Weld Joint
Authors: Xu Xue Xia , Feng Yan Ting , Li Wen Peng , Sun Peng , Ouyang Jie , Niu Xiao Guang
Published: June 2012

A kind of white massive microstructure in weld joint of P91 steel was first discussed by OM, SEM and EDS analysis. Results indicated that it is a kind of substance with low melting temperature other than the conventional delta ferrite. It contains high content of Cr due to improper choice of weld electrode and weld heat treatment. The existance of the abnormal microstructure will result in cracking under large stress for poor toughness. Solutions are suggested to prevent the formation of the white massive microstructure.
Welding Technology of SAF2507 for Offshore Platform
Authors: Sun Bo , Niu Hu Li , Tang De Yu , Fang Zong Tao , Hu Yan Hua
Published: June 2012

In recent years, super duplex stainless steel has been widely used in offshore platform for its excellent corrosion resistance. The key point of welding super duplex stainless steel is to ensure the phase ratio of welded joints. In this paper, the weldability, welding method, welding material, groove of SAF2507 were introduced. Then the test content of welding procedure qualification was described.
The Study on 1Cr18Ni9Ti and 2Cr13 Steel Welding Joints Corrosion Resistance Properties
Authors: Zhao Yong Tao , Dong Jun Hui , Liu Zong Chang , Zhou Jun Wei
Published: June 2012

By method of TIG, and under certain welding craft conditions,1Cr18Ni9Ti and 2Cr13 were welded. By (ZEISS) OM,SEM,the microstructure of two kinds of 2Cr13 and 1Cr18Ni9Ti welding joints were observed and analyzed, Through seawater immersion test, polarization curves and AC impedance spectroscopy of 1Cr18Ni9Ti and 2Cr13 welding joints were obtained. The results show that 2Cr13 and 1Cr18Ni9Ti welded joints is typical columnar crystal, the microstructure is lath martensite + austenite + carbide; polarization curves and AC impedance spectroscopy show that corrosion resistance of welding joint from strong to weak is: austenite base metal>HAZ near austenite>welded joint>HAZ near martensite>martensite base metal; corrosion resistance of welded joint is between martensite base metal and austenite base metal.
Thermoelectric Properties of Zn-Sb Thin Films Grown by Ion Beam Sputtering
Authors: Liu Peng Juan , Fan Ping , Zheng Zhuang Hao , Zhang Dong Ping , Cai Xing Min , Cai Zhao Kun , Chen Tian Bao
Published: June 2012

Antimony (Sb) and zinc (Zn) bilayer was sputter-deposited at room temperature with various Zn contents by ion-beam sputtering and transformed into Antimony zinc after post thermal annealed at 573K for 60 min. A power factor of 6.18×10-4 W/mK2 at 473 K has been obtained when the sputtering time of the Zn was 20 minutes. The maximum Seebeck coefficient is 42.0 μVK-1. Composition analysis shows that the compound of SbZn is achieved and the small Seebeck coefficient is due to the deviation of stoichiometric.
Mechanical Performance and Durability of Fly Ash Recycled Aggregate Concretes
Authors: Corinaldesi Valeria
Published: June 2012

According to the concept of sustainable development, the environmental load of a building must be evaluated throughout its life cycle, from design to construction, maintenance or repair, demolition, and rubble disposal. Therefore, from a holistic point of view, sustainable construction means designing a reinforced concrete structure with proper durability during a specified service life. This paper discusses the effect of partial and full replacement of natural aggregates by recycled concrete aggregates (RCA) in a fly ash concrete. Engineering properties and durability performance have been examined for mixtures designed with various proportions of the RCA by mass. Results obtained showed that the addition of RCA lowers concrete performance, but the combined use of RCA and fly ash could allow to achieve adequate engineering properties and durability.
Study on Fracture Test of Rocket Shear Pin
Authors: Zhang Meng Mei , Xu Wen Yao
Published: June 2012

In order to study effects of geometric parameters in fracture test, this paper used 3D modeling software Solidworks and finite element analysis software Deform to simulate the fracture process of rocket shear pin and study the effects on shear test while various geometric parameters change in the assembly of fixtures and shear pins. According the results we improved the fixtures of shear test. The new fixtures were used in the rocket shear pin fracture test.
Preparation and Photocatalytic Activity of Heteropoly Acids/Polyvinylidene Fluoride Thin Films
Authors: Wang Li Min , Du Zhong Cai , Li Qiang , Wei Si Meng
Published: June 2012

In this paper, catalysts of (NH4)4SiW12O40 supported on polyvinylidene fluoride(PVDF) thin films were prepared and characterized by IR and SEM.In addition,sunlight as the light source and simulation of dyes effluent (malachite green) as the research object, through the orthogonal experiments studied the factors that influence catalyst photocatalytic degradation effects,such as the amount of catalyst, pH, the amount of hydrogen peroxide . The results show that the degradation of malachite green of the heteropoly acid catalyst immobilized by membrane is best under the conditions of visible and achieve high degradation rate( 90% ). Also , the catalytic effect is also related with the oxidant dosage and the acidity. The catalyst is energy saving, easy recovery and has widest foreground.
The Impact Toughness and Fracture Behavior of Ni-Containing Powder Metal Steels
Authors: Wu Ming Wei , Shu Guo Jiun , Chang Shih Hsien
Published: June 2012

The toughness of powder metal (PM) steel is always inferior due to the presence of pores. An alloying element is typically found to improve the tensile strength, while sacrificing toughness. These issues prohibit the development of high-strength PM steels with satisfactory toughness. To formulate high-strength PM steels with superior toughness, the effects of Cr and Mo on the impact toughness and fracture behaviors of Ni-containing PM steels were investigated. The results indicated that both 1.5wt% Cr and 1.5 wt% Mo additives can improve the microstructures and tensile strengths of Ni-containing PM steels. However, while 1.5 wt % Mo apparently impairs the toughness, 1.5 wt % Cr does not. The addition of 1.5 wt% Cr results in the formation of Ni-rich martensite, which is strong and tough, thereby improving the tensile strength by 150% without sacrificing toughness.
Study on the Titanium Film in the Pressure Self-Adaptive Water-Tight Junction Box of Underwater Vehicle
Authors: Yuan Zhuo Li , Huang Hao Cai , Ye Yan Ying , Leng Jian Xing
Published: June 2012

Water-tight junction box (WJB) is one of key underwater vehicle technologies, which is indispensible in nowadays underwater engineering. Taking the advantage of large deformation range and corrosion resistance characters of the titanium material, this paper utilizes the titanium thin film material to put forward a titanium film pressure adaptive compensator (TFPAC) which solves the pressure problem and improves the reliability of the WJB greatly. The finite element analysis (FEA) software ANSYS is used to analyze the stress and strain condition of the titanium film when the film is suffering the internal pressure in the working condition. The feasibility and reliability of the Pressure Self-adaptive Water-tight Junction Box (PSAWJB) is tested and verified by hyperbaric chamber tests.
Effect of Ce on the High Temperature Mechanical Properties of Martensitic Stainless Steel
Authors: Liu Xiao , Li Jian She
Published: June 2012

The effects of Ce on the inclusions and the high temperature mechanical properties of 2Cr13 stainless steel were studied. The results show that the morphologies and sizes of inclusions in 2Cr13 stainless steel are changed, and Ce played a very good role of modifying inclusions. The high temperature strength of 2Cr13 stainless steel is improved obviously by Ce. In comparison with 2Cr13 stainless steel without Ce, the high temperature strength of 2Cr13 stainless steel with Ce is increased 18.18% at 1273K, respectively.
Microstructures and Tensile Properties of Electrodeposited Cu Sheets with Grain Sizes from Nanocrystalline to Ultrafine Scale
Authors: Zhang Han Zhuo , Zhang Huiping , Liu Lei
Published: June 2012

Four types of Cu sheets, with average grain sizes of 200 nm, 90 nm, 33 nm and 11 nm respectively, were electrodeposited and tested by tension at both high and low strain rate. Typically, a higher strength with lower tensile ductility was obtained by increasing the strain rate or reducing the grain size till 33 nm. An inverse Hall-Petch result was found in 11 nm Cu, while 200 nm Cu exhibited an increase of both strength and plastic strain by the increment of strain rate. Tensile deformation mechanisms of the Cu sheets were also discussed with their microstructural features.
Influence of Tempering Temperature on the Mechanical Properties of CrMnNiMo Steel
Authors: Li Jie , Wang Wen Ming , Gao Ji Xiang , Shao Wei
Published: June 2012

The mechanical properties of a new-invented CrMnNiMo steel tempered at 200°C~650°C were studied. The results show that mechanical properties are affected by tempering temperature severely. Strengths drop rapidly with increasing tempering temperature, concomitant with gradually rise of elongation and reduction in area. Yet impact energy decreases stepwisely, reaching minimum value at around 450°C and then ascends fast. Comparatively, optimum mechanical properties are reached at about 550°C. Fracture surface of impact specimen, dominated by dimples with different sizes, shows failure by microvoid coalenscence. Large amounts of complex inclusions, mainly Rare Earth-oxysulfides and aluminum oxides, sphericity or ellipsoid with dimension less than 10μm, are observed, which have little influence on mechanical properties.
Study on Mechanical Properties of Activated Carbon Fiber Reinforced Medium Density Fiberboard
Authors: Yang Yu , Liu Cheng , Han Cheng
Published: June 2012

Activated carbon fiber reinforced composites is a kind of new material in ceaseless development which is receiving more and more attention because of its excellent absorption and mechanical properties. This article mainly studies the influence of polyacrylonitrile based activated carbon fibers on the mechanical properties of medium density fiberboard (MDF); add the static bending strength and internal bonding strength (IB) of medium density fiberboard in the PAN-ACF through comparison test and get the result of the influence of polyacrylonitrile based activated carbon fibers on medium density fiberboard.
Delamination Analysis of Carbon Fiber-Reinforced PEEK Using Coarse Mesh
Authors: Ahn Jae Seok , Woo Kwang Sung , Lee Dong Woo
Published: June 2012

The simulation of the delamination process in composite structures made from carbon fiber-reinforced polyetheretherketone (PEEK) is quite complex and requires advanced finite element modeling techniques. Failure analysis tools must be able to predict initiation, size and propagation of delamination process. The objective of the paper is to present modeling technique which is able to predict a delamination in a double-cantilever-beam (DCB) test. The approach is to use a fracture mechanics criterion, but to avoid the complex moving mesh technique. The modeling technique using coarse mesh adopts higher-order approximation (p-level=8) based on Lobatto shape functions. For fracture analysis, also, virtual crack closure technique (VCCT) is considered. Using moving nodal modes, the delamination analysis is implemented and then the performance of present analysis is demonstrated by comparing with the results of references.
Singular Behavior of Laminated Skew Composite Materials with Cross-Ply Stacking
Authors: Ahn Jae Seok , Son Kwang Ik , Woo Kwang Sung , Shin Young Shik
Published: June 2012

This study deals with effects depending on skew angles in skewed-laminated composite materials in macroscopic point of view. Based on higher-order approximation of displacements, subparametric layer-wise finite elements are used to analyze skewed-laminated composite systems. The elements have higher-order shape functions derived from the Lobatto shape functions. The modes of the elements are classified into three groups such as vertex, side, and internal modes. The vertex modes have physical meaning, while side and internal modes with respect to the increase of order of the Lobatto shape functions do not have physical meaning but improve accuracy of analysis. Therefore, fixing mesh arrangement of present analysis, the quality of the analysis can be enhanced without re-meshing work. The approach based on p-version of finite element method is implemented with three-dimensional elasticity theory, while shape functions are developed by combination of one- and two-dimensional shape functions, not using three-dimensional shape functions. Using the accurate and practical proposed technique, macroscopic behavior of skewed-laminated composite materials is investigated.
Investigation on Forging Process of S20S Connecting Rod and its Defects Analysis
Authors: Zhou Lu , Wang Kai Kun , Song Shi Lei , Lu Lin , Li Chong Wei
Published: June 2012

In the heavy machinery and energy industry, forged connecting rods have been used more and more widely. Due to the complex process and large-size, it is a challenge to ensure the quality of large forgings. Different kinds of defects were produced during forming process. In this study, the forming process of S20S forged connecting rod was first analyzed. Then SEM and energy spectrum were conducted. The results showed that inclusions of sulfide and oxide were the main defects during forging of S20S connecting rod.
Effect of Martensite on the Dynamic Torsional Properties of a Dual-Phase Carbon Steel
Authors: Cao Tong You
Published: June 2012

Four different heat treatment routes which were called step quenching were taken and accordingly different morphology dual-phase samples have been obtained. It is found that Maximum shear stress increases with martensite volume increases. They have the following relationship: Maximum shear stress = 1.14(MVF)2 – 90.7(MVF) + 24266 MPa. Adiabatic shear bands and cracks led by them are important signs during the dynamic torsional tests