bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization by Grey Relational Analysis of EDM Parameters on Machining Ti-6Al-4V
Authors: Xie Zhi Ping , Zheng Ji Ming , Quan Bian Li
Published: October 2010

In this paper, parameter optimization of the electrical discharge machining process to Ti–6Al–4V alloy considering the multiple responses using the Taguchi method and grey relational analysis is reported. The multi-response optimization of the process parameters are material removal rate (MRR) and electrode wear rate (EWR). The machining parameters including discharge current, voltage, pulse on time and duty factor. Experiment based on the orthogonal array, The optimized process parameters simultaneously leading to a lower electrode wear ratio and higher material removal rate are then verified through a confirmation experiment. The experimental result for the optimal setting shows that there is considerable improvement in the process. The validation experiments show an improved electrode wear ratio of 2.8%, material removal rate of 45.8% when the Taguchi method and grey relational analysis are used.
Hot Deformation Behavior during the Hot Compression of AZ31 Alloy
Authors: Sun Shu Li , Zhang Min Gang , He Wen Wu , Zhou Jun Qi , Sun Gang
Published: October 2010

The hot deformation behavior of as-cast AZ31 magnesium alloys have been investigated at 200~400°C and strain rates 0.001~1s-1 by means of hot compression tests on a Gleeble-1500D thermal-mechanical simulator. We have analyzed the flow stress-strain curve and presented the constitutive equation by calculating stress exponent, activation energy and Zemer-Hollomon parameter. Then, the processing map of AZ31 alloys has been developed based on the dynamic material model theories and Prasad instability criterion. The flow instability domain is observed at lower temperature and the larger power dissipation rate is emerging at 300~400°C. We have analyzed the corresponding deformation microstructures and it is characteristic of dynamic recrystallization. These results have shown that AZ31 alloy has good workability at 300~400°C and lower strain rate.
Numerical Simulation of Back Pressure Influenced Aluminum Component’s HPDC Process
Authors: Cao Wen Jiong , Zhou Zhao Yao , He Yi , Wu Yuan Biao
Published: October 2010

Due to the flow behavior of molten metal is affected by the back pressure of mold residual air in high pressure die casting (HPDC) process, the back pressure conditions should be considered in order to simulate the HPDC process precisely. In this study, an aluminum colander of automobile’s filling process in HPDC was calculated by combining the back pressure conditions. The optimized schemes were given by considering the simulation results. Both initial and optimized schemes simulation results were compared with actual parts. The contribution of gas porosity between simulation and actual part were in agreement when back pressure conditions were applied. The local back pressure can be controlled by coordinating the position of the vents. Therefore the flow behavior of molten metal can be changed and the porosity defects can be fixed.
Investigation on Drilling-Induced Delamination of CFRP with Infiltration Method
Authors: Quan Yan Ming , Sun Lu Hua
Published: October 2010

Carbon fiber reinforced plastics (CFRP) are typical difficult-to-cut materials because of their anisotropic mechanical properties and poor heat conductivity. Drilling is the most common process in the manufacturing of CFRP products in which delamination is the most potentially damaging defect. In the present work the delamination damage around drilled hole of multi-directional CFRP is analyzed by means of infiltration inspection method with gold chloride solution, and the effects of drill rotational rate and feed as well as drill geometry on delamination are investigated, the damage degrees in laminas near the hole entrance and the hole exit are compared. The experiment proves the infiltration method is applicable for the investigation. The results show that the nearer the distance to the hole entrance or exit, the larger the remains area of infiltration agent is; the remains mark near the hole exit is larger and more irregular than that near the hole entrance, and it has the largest length in the direction along fiber length; a chisel-free drill, a high drill rotation rate combining with a small feed brings on the decrease of delamination damage.
The Shape Distortions Formed in Flat Bottom Punch Raising Process with TC2Mδ1.53 Titanium Alloy Sheet
Authors: Zhang Ling Yun , Zhang Bei Bei , Qiu Fu Sheng
Published: October 2010

Raising processes of titanium alloy sheets TC2M were simulated by using ADINA FEM software. The shape distortions induced by plastic anisotropy during forming and springback processes were described. A series of forming tests were conducted for the comparison of simulation predictions and test measurements. Reasonable agreement was obtained between the predicted and measured profiles of formed parts. Two sorts of shape distortion phenomena exhibited in the raised workpieces fabricated in room temperature after springback or elastic recovery process: Firstly, the bottom of the flange in the specimen was distorted to be a wavy surface and not a plane. There are two highest points and two lowest points, and the highest points located in the flange periphery along the transverse direction (TD), and the lowest points located in the periphery along the rolling direction (RD); Secondly, the top surface of the raising specimen was distorted to be a wavy surface too, and the distortion shape is similar to that in the flange.
Properties and CA4GE-Engine Test of TiAl-Based Alloy Valves by Permanent Mold Casting
Authors: Sheng Wen Bin , Ma Chun Xue , Gu Wan Li
Published: October 2010

TiAl-based alloy valves were manufactured by combining charges compressed /vacuum arc melting (VA)/ induction skull melting (ISM) procedure with permanent mold centrifugal casting method. Microstructures, compositions and mechanical properties of as-cast and hot isostatical pressed (HIPed) valves are detected. Results show that the permanent mold centrifugal casting process obviously refines the size of grain in TiAl alloy and the tensile strength of as-cast and HIPed valves are 550MPa and 580MPa at 20°C, 370MPa and 470MPa at 815°C, respectively. As-cast specimens show ~0% elongation at 20°C and 1~2% at 815°C, while HIPed ones show an elongation of 1~2% at room temperature and about 10% at 815°C. Furthermore, a 200-hour test was carried out with CA4GE-engine, which demonstrated the possibility of as-cast TiAl alloy valves for the substitution of present steel ones.
Research on the Blank Used in Integral Forming of a Lager Head with Supporting Table
Authors: An Hong Ping , Liu Jian Sheng , Wu Jian Guo , Tian Ji Hong
Published: October 2010

Three-dimension rigid-plastic finite element software, DEFORM-3D, was used to simulate the integral forming processing of a lager thick-wall semi-sphere head with supporting tables. Influencing factors of integral forming, such as initial blank shape, radius of corner at the bottom of the protrusions and the preforming mode etc, were researched quantitatively. A double layer frustum cone blank was determined, which can reduce the variable amplitude of the wall thickness and cause a uniform wall thickness distribution. When radius of corner at the bottom of the protrusions of the machined blank was in 100~130mm, no crack occurred at the bottom of the any supporting tables and a rational size can be obtained after forming. Using mode C (two banding protrusions) to forging the blank for machining can prevent the center metal from thinning and reduce additional tensile stress. Based on the simulation research, the 1:3 scale experiment was done in 31.5MN hydraulic press and the test piece was measured. The result shows that the error between simulation data and test data is less than 5%, which verified the feasibility of integral forming and provided an important reference for virtual production.
Experimental Research on Impact Line of Hyperboloid Shallow Shell
Authors: Zhao Li Hong , Ren Zheng Yi , Jiang Shu Yong , Yang Nan
Published: October 2010

Impact line is one of important factors to affect the shape accuracy and surface quality of auto body panel design and manufacture. It is difficult to study because of the complexity shape of auto body panels. The system of test analysis on impact line is established by analyzing the shapes and forming processes of auto-body panels, of which based on hyperboloid shallow shells. The criterion and research technique of impact line are introduced. Extensive experiment results, which show the effects of forming process conditions, such as blank holding force, draw bead arrangement, and lubrication on impact line, are achieved. It can be concluded that the draw bead arrangement significantly influence the impact line, the displacement of impact line is different with difference of blank holding force and the friction coefficient.
Crush Performance of Top-Hat Tubular Structures Considering Different Forming Conditions
Authors: Niu Jian Hui , Zhu Ping , Guo Yong Jin
Published: October 2010

The influence of forming condition on crash performance of thin-walled structures is investigated, in which high strength low alloy steel HSLA340 and dual phase steel DP590 are considered. Stamping and knife-edge-bending process were carried out respectively to form hat channels, and then, impact tests were performed on the spot-welded top-hat sections subjected to quasi-static and dynamic axial loading conditions to identify the forming effect on the crashworthiness. Regular progressive buckling (quasi-inextensional mode) was observed for knife-edge-bent specimens, while the stamped specimens showed peculiar collapse mode, especially, global instability existed for all the specimens under dynamic impacting and their energy absorption capacity was significantly reduced. The result demonstrates that for accurate assessing the structural performance detailed stamping history of sheet metal components should be taken into consideration.
Application of Numerical Simulation on Cast-Steel Axle’s V-Method Foundry
Authors: Mi Guo Fa , Chen Li Lin , Nan Hong Yan
Published: October 2010

The V-method foundry is an advanced casting technology compared with traditional sand casting. The Pro/E software was used to generate three-dimensional model of cast parts. The solidification process of the automotive axle casting with V-method foundry was simulated by the numerical simulation software, ViewCast. The location and scale of the shrinkage defects caused by the original process were predicted. According to the simulation results, the position of the flange round cooled too fast, which blocked the feeding passage of the round near sprue. The reason was that solidifying sequence was unperfected. The casting process was optimized by means of adding runner and chill. Progressive solidification can be obtained and the shrinkage defects can be eliminated or transferred by the improved technology. The reasonable casting process was obtained and the process has been proofed by the productive practice.
Research and Prospects of Laser Welding Technologies of Magnesium Alloys
Authors: He Bo Lin , Liu Jing
Published: October 2010

Comparing with traditional welding technology, there are many advantages of magnesium laser welding, for example, high welding speed, low line energy, small welding distortion, easy to achieve automate production et al. It is widely used in the area of magnesium welding. Fine microstructure and excellent weld shape can be obtained by choosing reasonable technology parameters and the mechanical properties of welding joint can also be promoted. But there are some defects in the process of welding magnesium alloys with laser, such as, stomas, cracks, impurities and so on. Some actions can be taken to improve or prevent those defects. For example, choosing the appropriate process parameters can solve the problem of cracks, impurities. In this paper, the status of laser welding magnesium alloy is reviewed in recent years, and some problems in magnesium laser welding were analyzed and some suggestions of solving the problems were put forward.
Gap Setting Model and Application in Plate Rolling Process
Authors: Zhao Zhong , Jia Chun Li , Hu Xian Lei , Wang Guo Dong , Zhu Zhen Hua
Published: October 2010

According to the characteristic of plate rolling process and the on-line applications, the non-homogeneous wear and thermal expansion of rollers, the elastic recovery and thermal expansion of work pieces, the variation of oil film thickness and the zero point deviation, which influence the precision of gap setting model, are analyzed. Based on the results of analysis, a high-precision gap setting model is proposed, and a zero point correction method is developed, in order to avoid overshoot, damp coefficient, which is affected by the thickness of work piece and zero point deviation are considered, is introduced. On-line applications indicate that the gap setting model improves the precision of gap setting and laid a good foundation of further improvement of thickness accuracy.
The Research for Drawing Process of High-Speed Railway’s Track Template
Authors: Sun Hong Lei , Yin Jing , Ma Rui
Published: October 2010

The track template is a crucial part of the high-speed railway’s track constructing, and the manufacture experiences are still lacked in China. In this paper, the two times drawing process scheme is based on FEA of Dynaform. The pre-forming is the key step of the whole process. The performing scheme was established by simulation and experiment. The pre-formation’s experimental results and simulation results are well coincided. The max relative error of width reaches 1.22%, and the max relative error of length is less than 4.86%. The eligible parts were formed by the drawing process and pilot production has applied to engineering practice.
Tensile Strength Prediction of Woven Composite Bonded Joint
Authors: Zhang Jian Yu , Fu Yue , Zhao Li Bin , Chang Hai Feng , Fei Bin Jun
Published: October 2010

A progressive damage method is adopted to predict the structural strength of a woven out-of plane composite bonded π joint. A 3D progressive damage model is established and analyzed via a user defined subroutine embedded into the general FEA package. The numerical prediction gives the information of damage onset, damage propagation and final failure pattern, initial and final failure strength. Three samples of woven composite π joint under tensile load are tested to verify the numerical results. The numerical prediction agrees well with the experimental outcomes. All the numerical and experimental results provide insight into the basic understanding of static strength of woven composite bonded π joint.
Prediction of Springback in Metal Forming of Diaphragm of Automotive Horn Based on BPANN
Authors: Zhang Yan Qiu , Jiang Shu Yong , Zheng Yu Feng
Published: October 2010

The spring steel strip 50CrVA which is cold rolled was applied to manufacture the diaphragm of the automotive horn by means of sheet metal forming. The combination of the experiments with back-propagation artificial neural network (BPANN) is used to solve the springback problem of the diaphragm. Experiments have shown that a 4-8-1 BPANN is able to predict the springback of the diaphragm successfully, and the network is able to model the relationship between the springback of the diaphragm and the process parameters rationally. BPANN simulation results and experimental ones have shown that the springback of the diaphragm is particularly influenced by such parameters as blank thickness, Young’s modulus, punch radius and yield ratio. Furthermore, the springback of the diaphragm decreases with the increase of blank thickness and Young’s modulus, but increases with the increase of punch radius and yield ratio.
Role of Material Properties in Improving Sheet Formability in SPIF Process
Authors: Hussain Ghulam , Hayat Nasir , Gao Lin
Published: October 2010

Single point incremental forming (SPIF) is a novel sheet metal forming process. Owing to unique deformation mechanism, this process improves the sheet formability as compared to the conventional stamping process. In the current paper, the mechanical properties and spifability (i.e. formability in SPIF) of a wide range of materials were tested. The mechanical properties were mainly determined through tensile testing and the spifability was evaluated using Varying Wall Angle Conical Frustum (VWACF) test. Each mechanical property was drawn against the improvement in sheet formability (i.e. difference of spifability and stampability) and the sole most influential property was identified. It was found that the improvement in formability increases with the increasing of true thickness strain at tensile fracture.
Thermal Deformation Behavior of 1Cr12Ni3Mo2VNbN Alloy and Its Application in the Blade Forging
Authors: Zhong Jie , Guo Chen , Yue Peng , Long Chun Liang
Published: October 2010

Thermal deformation flow stress equation of 1Cr12Ni3Mo2VNbN in the temperature range of 980 °C~1180 °C is established by means of hot simulation test and the regression analysis. The results show that the data obtained accords with hyperbolic sine function and the equation will also enrich the material performance database. The established equation is used in the blade forging production based on numerical simulation technology, and the numerical simulation results show that utilizing flat head billet can solve the problem of filling dissatisfaction at the root of the blade. Adopting water-based graphite lubricant provides better lubrication condition for blade forging. The equipment wear and energy consumption can be reduced by applying initial forging temperature of 1130°C in the blade forging process. The application of thermal deformation flow stress equation and numerical simulation technology can reduce the number of trial production, shorten the process design cycle and improve production efficiency in a large extent.
Effects of Steel Coatings Microstructure on Weldability in Resistance Spot Welding of Galvannealed Steel Sheets
Authors: Hu Xin Bin , Zhou Xiao Ping
Published: October 2010

Effects of steel coatings on weldability in resistance spot welding of galvannealed steel sheets were investigated. The steels with different coatings, where Fe content changed from 7.0 wt% to 11.4 wt%, were welded by alternating current (AC) welding machine. The results showed that the weldability in RSW of the GA steel with 11.4 wt% Fe was the best in three researched steels. Higher Fe content in the coating resulted in increased contact resistance and hence reduced welding current needed and increased the range of weld current in RSW.
Finite Element Simulation for the Stress of Cavity Die Wall in Tube Open-Die Cold Extrusion Process
Authors: Pei Wei Chi , Han Ju , Li Yao Gang
Published: October 2010

The service life of open-die cold extrusion is the most important factor in economic efficiency. To prolong its service life, the design of the die needs a rational structure. Studying the stress of the die wall and its distribution rule is the precondition in cavity die optimization design. Numerical simulation for tube open-die cold extrusion process using finite element software Deform-3D, the distribution of the stress of die wall, the influence rule of the stress of cavity die wall under various kinds of the processing parameter and the optimum range of stress of cavity die wall. The analysis result can take some effective measures to rational design for the die to decrease the die defect, prolong the service life of the die and increase economic efficiency. It can also offer references for optimization design of cavity die.
Study on Formability of Tailor-Welded Blank Based on Sheet Metal Matching
Authors: Wang Jin Lun , Lan Feng Chong , Chen Ji Qing
Published: October 2010

As tailor-welded blank having two or more sheet metal welded together, with different mechanical properties, coating and thicknesses, its yield strength and tensile strength are higher, but hardening exponent and elongation are lower than a single sheet. The different mechanical properties of substrates and weld movement have significant effects on TWB’s formability, different materials or thicknesses easily lead to uneven deformation and forming defects such as cracking, wrinkle and springback. This paper takes tailor-welded box-shaped part for example; the forming process and weld movement were simulated and analyzed. In this process, the weld type was ignored, only considering the weld-line position, using segmented blank holder to control the size of the blank holder force on both sides respectively. Three cases of sheet metal matching were carried out including: different thicknesses with same material, same thickness with different materials, and different thicknesses with different materials. Finally, some meaningful results were obtained.
Study on the Casting Process of the Large-Scale High-Chromium Cast Iron Impeller
Authors: Qiao Feng Li , Yin Yi Min , Zhi Xiao Hui
Published: October 2010

The cracking tendency of large-scale high-chromium cast iron impeller was large, and its casting production was a problem in slurry pump industry. The casting process of the largest high-Chromium cast iron impeller in China was presented in this paper. Through casting process design and alloy composition design, the produced impellers met the quality demands, such as no crack, surface smoothness and high hardness. Huazhu CAE was used to simulate the casting process and the parameters used in the simulation were introduced. The STL document used in Huazhu CAE was converted from the 3D molding of the casting process using the Solidwork software. The simulation result showed that the casting process was feasible. They have been successfully used in the dredge, New Sea lion.
Three-Dimensional Numerical Simulation and Forming Investigation for Net-Shape Forging of Spur Gears
Authors: Xu Shu Bo , Jing Cai Nian , Wang Gui Qing , Ren Guo Cheng
Published: October 2010

In this paper, a new precision forging technique composite processing of the moving-die forging and divided flow forging process to form the spur gear is introduced. A systematic investigation of the floating-relief method process is performed by using finite element numerical simulation. The stress distributions on the workpieces were obtained. The closer the die teeth corner is, the higher stress value results can be acquired. And the effective stress is concentrated in spur gears forging die cavity corner. It was found that the floating-relief method forging process with upper and lower convex punches control the material flow effectively and the tooth cavity is filled successfully during the performing forging and final forging. The proposed method can serve as preconditions to analyze the abrasion and fatigue of spur gears forging die. The obtained results can offer valuable guidelines for gear precision forging experiments and practical process planning.
Synthesis of Al2O3/AlB12/Al Composite Ceramic Powders by High Frequency Induction Heating Method and a Study of Their Mechanical Properties
Authors: Huang Kai Jin , Tan Chao Dong
Published: October 2010

Pure Al2O3/AlB12/Al composite ceramic powders have been synthesized using high frequency induction heating method. This method starts from Al and B2O3 powder mixtures, after which Al2O3/AlB12/AlN composite ceramics were fabricated by hot-press sintering at 16000C for 2h under the protection of a N2 atmosphere. The bending strength and the fracture toughness of the ceramics were measured by the three-point bending method and the indentation fracture method, respectively. The results show that the pure Al2O3/AlB12/Al composite ceramic powders can be successfully synthesized by high frequency induction heating method. Al2O3 and AlB12 phases were formed by the liquid-liquid reaction mechanism and the liquid-solid reaction mechanism, respectively. The bending strength and the fracture toughness of the Al2O3/AlB12/AlN composite ceramics were 549.48MPa and 5.96MPa.m1/2, respectively. These values are 56.99% and 49% greater than those of the pure Al2O3 ceramic (350MPa and 4MPa.m1/2).
Numerical Simulation of Multi-Component Powder in Selective Laser Sintering
Authors: Zhang Jian , Li De Ying , Fu Wei , Zhao Long Zhi
Published: October 2010

The process of sintering material from the powder to the liquid with high temperature and then to the continuous solid are simulated, considering the effects of heat conduction, thermal radiation, thermal convection and thermal physical parameters on temperature. The results show that the temperature gradient is larger in the front of pool, and the end of which is smaller due to the fast-moving laser beam and uneven distribution of laser energy. With the increase of scanning time, the overall temperature of substrate and powder particles is gradually rising, the heat-affected zone is increasing and the asymmetric temperature distribution has become more obvious for the heat conduction. As the pool depth is larger than the powder thickness and the pool width is larger than the scanning spacing at the current process parameters, the bond strength of layers and scanning lines is enough.
On Cutting Process of Stainless Steel Fiber with Complex Surface Morphology
Authors: Tang Biao , Tang Yong , Zhou Rui , Wan Zhen Ping
Published: October 2010

To meet the increasing application requirements of stainless steel fibers with rough surface morphology, a self-made multi-tooth tool which can bifurcate chip during the cutting process was utilized to manufacture stainless steel fibers. The novel cutting method can achieve efficient processing of continuous stainless steel fibers with complex surface morphology. The influence of cutting parameters (back engagement ap and feed rate f ) on forming process of fibers’ surface morphology was studied. The cutting experiments were carried out under the condition of selected tool and fixed workpiece rotating speed. The results show that: the surface morphology of stainless steel fiber is simultaneously effected by ap,and feed rate f .Between them, ap has more significant effect on it. In order to obtain stainless steel continuous fibers with coarse surface morphology, the optimum cutting parameters were recommended as follows: ap∈(0.1-0.2) mm, f ∈(0.1 -0.17) mm/r.
Numerical Simulation and Sensitivity Analysis for Tube Hydropiercing Quality Based on Experiments
Authors: Wu Zhi Gang , Li Shu Hui , Zhang Wei Gang
Published: October 2010

In the present work, the ductile fracture process of hydropiercing is simulated using Rice and Tracey ductile fracture criterion by means of the user subroutine VUMAT of ABAQUS. The simulations at different loading pressures coincide well with the experiments. Based on this criterion, the processes of hydropiercing at different technical conditions are simulated with orthogonal design and the sensitivity analysis of parameters is conducted. The sensitivity analysis shows that internal pressure plays the most important role in controlling quality of the hydropierced products, namely the sheared zone length, roll-over depth and whole coefficient Y. High pressure and better lubricant are better for all the three indexes. Large punch corner radius is better for sheared zone length and Y but worse for roll-over depth. Additionally, it is found that internal pressure and punch corner radius could be intensified each other at conditions of both larger values.
Equation of Equilibrium Moisture Content of Wood under Vacuum by Regression Analysis
Authors: Yi Song Lin , Zhou Yong Dong , He Zheng Bin , Feng Xiao Jiang , Zhang Bi Guang
Published: October 2010

Relationship among equilibrium moisture content (EMC), temperature and pressure was established under vacuum condition, and EMC regression equation was constructed based on experimental data, with Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) as Experimental material, and MC was measured by oven-drying method. The experimental temperature range was from 40 to 90°C at the interval of 10°C, and pressure range was from 0.02 to 0.08 MPa at the interval of 0.02 MPa. EMC Comparison of Chinese fir and paper wafer sensor showed: EMC of paper wafer sensor changed in the same trend of solid wood. A regression equation was presented and the calculated EMC value was highly correlated with experimental data. This regression equation can be used to predict EMC under vacuum, especially for automatic control system of wood drying under vacuum.
Preparation and Properties of Low Formaldehyde Emission Plywood with Flame Resistance
Authors: Zhang Shi Feng , Song Fei , Gao Qiang , Li Jian Zhang
Published: October 2010

In order to improve the flame resistance and reduce the formaldehyde emission of plywood, a multifunctional formaldehyde scavenger with flame resistance (FSFR) was prepared and used to treat plywoods bonded with high molar ratio urea-formaldehyde (UF) resin. The weight percent gain (WPG), formaldehyde emission, oxygen index (OI), and bonding strength of plywoods after FSFR treated were measured to evaluated properties of FSFR. The results showed that the formaldehyde emission of the treated plywood was 0.1-0.32 mg/L, which could meet the E0 grade requirement (<0.5 mg/L ). The flame resistance of treated plywood increased significantly and the bonding strength changed little. The formaldehyde emission decreased 96.8 % and OI increased 47.2 % and the bonding strength kept unchanged when FSFR reached 8.87 % compared with that of untreated plywood.
Study on Fractal Characteristics of Primary Phase Morphology in Semi-Solid A356 Alloy
Authors: Liu Zheng , Liu Xiao Mei
Published: October 2010

Semi-solid A356 slurry was prepared by compound process, and the fractal characteristic of primary phase morphology was researched. The fractal dimensions of primary phase morphology in semi-solid A356 alloy were calculated by the calculating program written to calculate the fractal dimensions of box-counting in the imagine of morphology of semi-solid primary phase in A356 alloy. The results indicated that the primary phase morphology in semi-solid A356 prepared by compound process is characterized by fractal dimension, and the primary phase morphology prepared by the different technology parameters had different fractal dimensions. The primary phase morphology at the different position of ingot had the different fractal dimensions, which reflected the effect of solidified conditions at different position in the same ingot on the morphology of semi-solid primary phase
Research on Semi-Solid Y112 Alloy Fabricated by Mechanical Stirring
Authors: Yan Hong , Hu Yong
Published: October 2010

Effects of different technological parameters such as stirring temperature, stirring speed and stirring time on the microstructure of semi-solid Y112 alloy were investigated using a self-developed mechanical stirring device in this paper. The results show that the higher of stirring temperature and stirring speed, the finer and more homogeneous the spherical grains, the higher the tensile strength and elongation. If the temperature is too high, the solid grains will be melted, the tensile strength and elongation will be reduced. With the increasing of stirring time, the grains firstly become fine, uniform and round, and then grow up. The tensile strength and elongation firstly increase, and then reduce.
The High Temperature Gel Permeation Chromatography Study on Poly (Phenylene Sulfide) Linear Chain Propagation
Authors: Zhou Yu , Cheng Bo Wen , Li Zhen Huan , Shen De Xin , Zhang Sheng , Feng Hai Liang , Zhang Lei , Zhang Ma Liang
Published: October 2010

A linear and high molecular weight poly(phenylene sulfide) (PPS) was synthesized from P-dichlorobenzene (P-DCB) and anhydrous sodium sulfide in N-methyl pyrrolidone (NMP), and the High Temperature Gel Permeation Chromatography (HTGPC) technique was utilized to investigate the effects of reaction condition on PPS chain propagation. The experiment results indicated that the high pro-reaction temperature or high post-temperature would interfere with PPS chain propagation, and post-reaction time was another important factor to influence PPS molecular weight (Mw) extension. Furthermore, the optimized ratio of high Mw PPS polymer synthesis was typically at 3-6% molar excess of Na2S over p-dichlorobenzene, and N-methyl-2-pyrrolidone (NMP) were beneficial to the production of high Mw PPS due to the formation of sodium 4-(N-methylamino) butanoate (SMAB). The alkaline reagents such as Na3PO4 and K3PO4 et al could capture the H of -SH, which changed -SH into -SNa and promoted the chain growth of PPS to achieve extension.
Influence of Duty Cycle on Composition and Microstructure of Siliconized Layer Using Pulse Electrodeposition
Authors: Yang Hai Li , Li Yan , Li Yun Gang , Tang Guo Zhang , He Ning , Zhang Yu Zhu
Published: October 2010

The siliconized layer was pulse electrodeposited on grain oriented low-silicon steel sheet substrate in KCl-NaCl-NaF-SiO2 molten salts and the influence of duty cycle on the composition and microstructure of the siliconized layer was investigated. The results showed that when the duty cycle was in the range of 10% to 50% at average current density 30mA/cm2, Si content of siliconized layers was similar and the thickness of the layer was did not change much with different duty cycle. Cross sectional observation revealed that the siliconized layers had a two-layer structure. The top layer composed of columnar grains and a transition layer with equiaxed grains was close to the substrate. The layer was unsmooth when the duty cycle was 10%. While the surface appeared smooth and dense and the grains were fine when the duty cycle were 20% and 30%. The layer became more porous as the duty cycle increased to 40% and 50%.
Study on Mechanical Properties and Physical Properties of Copper Based Electrical Contact Materials Reinforced by CNT
Authors: Guo Zhong Quan , Geng Hao Ran , Feng Sha Sha
Published: October 2010

A new method of carbon nanotube with electroless plating of nickel is proposed. It is shown that in a certain condition, the compacted and well-distributed coating of nickel is obtained without the process of sensitization and activation. Upon the surface treatment of the carbon nanotube, the CNT-consolidated composites for copper-based electrical contact have been made in the way of powder metallurgy. Some important mechanical properties and physical properties, including sliding wear property, electrical conductivity and fusion resistance, were investigated. The experiment results showed that Carbon nanotube inside the composite was uniformly distributed and a proper addition of CNT effectively improves the comprehensive property of the composites. When the carbon nanotube takes up 4vol. % in the material, it is highly effective in improving its sliding wear property and fusion resistance; though its electrical conductivity drops. Its overall properties meet the requirements of electrical contact materials
Effects of N Content on Microstructure and Properties of SAF2906 Casting Super Duplex Stainless Steel after Cryogenic Treatment
Authors: Xiang Hong Liang , Liu Dong , Huang Wei Lin , He Fu Shan
Published: October 2010

SAF2906 is a new kind of super duplex stainless steel, and more corrosion-resistant and strong than SAF2507, suitable to be used in the low temperature and corrosion conditions. In order to prevent the occurrence of microstructure changes resulting in the property deterioration, in the general, the castings made for SAF2906 should be cryogenically treated before they are used in the ultra low conditions. N is an alloying element, usually added to stainless steels to increase the material properties. So, In this paper, the effects of N content on microstructure, mechanical and corrosion resistance properties of SAF2906 casting super duplex stainless steel (SDSS) after cryogenic treatment were studied by means of Optical Microscope(OM), X-ray Diffraction(XRD) and electrochemical workstation. The results indicate that N can increase the amount of γ phase according to a linear relationship of Φ(γ)=99.4×w(N)+6.16. When N content is low or medial, γ phase can precipitate from ferrite. When N content is high, γ phase does not precipitate from ferrite and is converted directly from ferrite and austenite grain boundaries. The higher N content, the greater tensile strength and elongation, the better corrosion resistance. Compared with solution state, cryogenic treatment can improve corrosion resistance.
Effect of Ultrasonic Treatment on Microstructures of Mg-Ca Binary Alloy
Authors: Zhang Zhi Qiang , Le Qi Chi , Cui Jian Zhong
Published: October 2010

The effects of high intensity ultrasonic melt treatment on the microstructure of magnesium alloys were investigated in this paper. Magnesium melts were treated with power ultrasonic wave and then cooled to a predetermined temperature. With the increase in ultrasonic power, the structure exhibited refined and spheroidzed crystal grains. After further increasing the ultrasonic power, the grains tended to somewhat coarsened. Increasing the ultrasonic processing time led to a grain refinement of magnesium alloy.
Machining Process of Titanium Alloy Based on Green Cooling and Lubricating Technology
Authors: Zhang Yue , Han Li , Li Qi Dong , Sun Tai Li , Zhang Xi Chuan
Published: October 2010

The machining process of titanium alloys always need special control by using coolant and lubricant as it is one of the difficult-to-cut materials. To achieve green cutting of titanium alloy Ti-6Al-4V with water vapor cooling and lubricating, a minitype generator is developed. Compared to dry and wet cutting, the using of water vapor decreases the cutting force and the cutting temperature respectively; enhances the machined surface appearance. Water vapor application also improves Ti-6Al-4V machinability. The excellent cooling and lubricating action of water vapor could be summarized that water molecule has polarity, small diameter and high speed, can be easily and rapidly to proceed adsorption in the cutting zone. The results indicate that the using of water vapor has the potential to attain the green cutting of titanium alloy instead of cutting floods.
Internal Oxidation of Rare Earth Additive Accelerating Aluminized Layer on Copper Matrix
Authors: Tian Bao Hong , Zhang Yi , Liu Yong , Ren Feng Zhang
Published: October 2010

The aluminizing treatment on the surface of commercial pure copper with addition of rare earth compound CeCl3 was carried out. The followed internal oxidation of the aluminized copper was also carried out in the industrial nitrogen gas flow. The influences of the aluminizing and internal oxidization processing time on the thickness, hardness profile and microstructure were investigated. Results show that the addition of rare earth oxide CeCl3 has great accelerating effect on the aluminizing and internal oxidation processing. The hardness of the surface Al2O3 dispersion hardened copper composite layer by means of internal oxidation with addition of rare earth compound is higher than that of the without addition. The internal oxidation mechanism of the aluminized layer on copper matrix is comprehensive processes of the oxygen inner-toward diffusion and localized internal oxidation of the inner-toward diffusion of aluminum.
A New Spectral Analysis Technique Used in Converter Steelmaking BOF Endpoint Control
Authors: Xu Ling Fei , Li Wu Sen , Xu Shi Xue , Li Jia , Wang Yong Qing
Published: October 2010

This article introduces an arithmetic approach to establish an optical system aiming to eliminate the shortcomings in the steel making technique. The current basic oxygen furnace technique is flawed because the level of carbon content in the molten iron is estimated by the workers observation through experience. It is hard to compare, measure and control. The proposed model, on the other hand, is much more computable: relevant data is collected from spectrum distribution during the process of basic oxygen furnace. It predicts the end-point of BOF relatively accurate because spectrum is quantifiable, and the changing process of the furnace flame is essentially the changing process of the spectrum. In this model, we can measure the temperature of the molten steel by the Flame emission spectroscopy theory principle. Further more, the result of the experiment conducted based on the model shows that the model meets the requirements of endpoint judgment online.
Research on Effect of La on Microstructure in Semi-Solid A356 Alloy
Authors: Liu Xiao Mei , Liu Zheng , Hu Yong Mei
Published: October 2010

Semi-solid A356 alloy slurry grain-refined by Al-La master alloy is prepared by low superheat pouring. The effects of La on the morphology and size of primary grain in semi-solid A356 alloy are researched. The results indicate that the semi-solid A356 alloy slurry with particle-like and rosette-like primary grains can be prepared by low superheat pouring. The size and morphology of the primary grain in semi-solid A356 alloy are markedly improved by La. The refining mechanism of La on the morphology and size of the primary grain in semi-solid A356 alloy is delved. The eutectic reaction of Al-La binary alloy provides the effective nuclei for formation of the primary grains in semi-solid A356 alloy.
Study on Influences of Injection Process Parameters on the Mechanical Properties of the Modified Polypropylene Products with Weld Lines
Authors: Qian Yu Qiang , Sun You Song , Xiao Xiao Ting , Yang Guo Hua
Published: October 2010

Influence of weld lines is important to the mechanical properties of the modified polypropylene products. Orthogonal experiments are adopted to confirm injection process parameters for such mechanical properties as impact resistance and tensibility of the modified polypropylene injection-molded parts in weld lines. The factors which affect the mechanical properties at welding joints product vary, and how to select rational parameters is a difficult problem for production. The mechanical strength can be increased through higher temperature, lower injecting pressure, higher velocity of filling, higher packing pressure and longer packing time. The specifications of cross section in weld lines of the products are analyzed to illustrate the theory of fracture. In order to increase mechanical strength of the sample, the length of hot weld lines should be increased and the length of cold welding joints should be decreased through adjusting the process parameter.
Experimental Research on Deep Cryogenic Treatment Process of YT30 Cemented Carbide Inserts
Authors: Yan Hong Juan , Xu Hong Hai , Li Xin Min
Published: October 2010

Deep Cryogenic treatment (DCT) is a one time permanent process, carried out in such a way that the material is slowly cooled down to the cryogenic temperature, after which it is held at that temperature for a specified period of time and is heated back to room temperature at slow rate followed by low temperature tempering. In this study, the orthogonal experiment method was used to study the DCT process of YT30 cemented carbide inserts. The primary relation of the different factors of DCT was analyzed. TH300 sclerometer was used to measure the hardness of inserts. The microscopes were used to observe the wearing profiles of inserts and microstructures before and after DCT. The orthogonal experiment results show that the effect of soaking temperature on the properties of inserts is the first factor, the soaking time is second one, the cooling rate is third one, and the last one is the tempering temperature. DCT improves the multi-type martensite transformation of Co. Therefore DCT increases hardness and enhance wear resistance of the cemented carbide inserts.
Preparation and Application of Modified Soybean Protein Adhesives
Authors: Sang Zi Tao , Zhang Shi Feng , Gao Qiang , Li Jian Zhang
Published: October 2010

In this study, a sodium hydroxide modified soybean protein adhesive (NSP adhesive) was prepared and mixed with phenol-formaldehyde (PF) resin in a ratio of 7:3 to form a compound adhesive (NSPF adhesive), and three-layer plywoods were prepared using the NSP adhesive and the NSPF adhesive. In order to understand the reactions between SP and PF resin during the curing process of NSPF adhesive, the SEM and FTIR spectra were employed to character the adhesives and the bonding strength of the plywoods was measured. The results showed that the bonding strength of the poplar plywood prepared with NSPF reached 1.00 MPa, and met type I plywood requirement in GB/T 17657-1999. There was new absorption peak appear at 1390 cm-1 in the FTIR spectra of NSPF adhesive, indicating that there were -NHCH2- structures generate in NSPF during the curing process in this research.
The Study on a New Wood-Based Carrier of Controlle and Release of Fertilizer
Authors: Duan Jiu Fang , Li Jian Zhang , Zhang Li Ping
Published: October 2010

This study prepared a wood-based hydrogel, which was studied as a fertilizer controlle and release carrier. The wood-based hydrogel was prepared by solution polymerization and whose structure was characterized by FTIR spectra. The water absorbing capacity and urea adsorption capacity were studied. The result shows that: With increasing degree of grafting yield, the water absorption increased at first and decreased afterward. The maximum appear at the glutaraldehyde amount of 0.4 times. The urea adsorption of the wood-base hydrogel has a strongest value in 10% aqueous solution of urea. The drug loading changed by the degree of crosslinking hydrogel and the wood content in the wood-based hydrogel. Hydrogel has a good adsorption capacity of urea,the hydrogel water absorption and urea absorption ability can be adjusted by the grafting rate. The wood powder prepared hydrogels is a new environmental protection materials, which has good prospects in controll and release of pesticides and fertilizers
Implementation of Distributed Control for Smelting Furnace and Mixed Gas Processes
Authors: Zhu Xiao Qing
Published: October 2010

A distributed system can be defined by three dimensionality: hardware, control functions and information data base. This paper introduced an example of the implementation and its design philosophy for a smelting and gas treatment project with their hardware and field control functions distributed by intelligent fieldbus devices and some modeling control functions and advanced control functions distributed to different data base in different segment stations. System integration was implemented successfully not only for their hardware, but also for their control functions and information data bases. Benefit of this project also can be obtained with respect to engineering, operation and maintenance.
Modification Microstructures in In Situ Mg2Si Reinforced Al-Si Alloy Composites
Authors: Jing Qing Xiu , Deng Geng Feng , Liang Yong
Published: October 2010

Effects of several different additions on microstructures in in-situ Mg2Si/A1-Si composites were investigated. The results show that rare earth elements have a selective modification effect on eutectic Mg2Si and Si structures. Al-Ti-B modifier should be introduced appropriately more into the composite, so as to effectively refine primary α-Al grains. As (SrCl2+RE) added increases from 0.4wt% to 2.0wt%, morphology of primary Mg2Si in a 12.0Mg2Si/A1-7.6Si composite is changed from polyhedron (or octahedron) to more irregular polyhedron with a size decrease from about 21μm to 6μm, while eutectic Mg2Si is changed from coarse dendrites to dispersed slim fibers. (RE+Al-P) can improve microstructures and tensile strength of a 7.9Mg2Si/A1-7.8Si composite; after modified by 0.8wt% (RE+Al-P), fracture surface of the composite is changed from cleavage to a mixed mode.