bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Study between DSC and Two Complementary Performance Evaluation Methods for PCM-Treated Textiles
Authors: Mohaddes Farzad , Islam Saniyat , Shanks Robert A. , Wang Li Jing , Padhye Rajiv
Published: June 2014

Evaluation of thermoregulation performance of textiles incorporated with phase change materials (PCMs) has long been dependent on differential scanning calorymetry (DSC). However, some parameters like the time required for reaching the steady state and the effect of multiple layering cannot be characterized by calorimetric methods. In this paper, Newton cooling law was fitted to the temperature–time graphs of PCM-treated and untreated fabrics obtained by a digital data-logger. By definition, lower values of α in Newton cooling law associates with higher thermoregulation effect. The effect of using different layers as well as thermoregulation efficiency of PCM-treated fabrics were investigated by this method. Thermal imagining was another method employed to calculate thermoregulation percentage (TP) of the fabrics exposed to an infrared, IR, light source. The temperature–time graphs obtained by an IR camera were populated, and the corresponding TP percentages were calculated by image analysis. At the end, the results obtained by two suggested methods were qualitatively compared with DSC.
Process Design of Strengthening and Toughening Treatment for 65Mn Steel by Powder RE-Boronizing Method under Low Temperature
Authors: Yuan Xiao Ming , Wang Hong Yu , Zhao Yu Feng , Xu Xiao Jing , Cheng Man
Published: June 2014

In order to improve the surface wear-resistance and overall shock-resistance of 65Mn steel, effects of rare earth (RE) particle size, adding amount and boronizing time subjected to quenching and medium-temperature tempering treatment were studied systematically. Optimizing basic component of low-temperature boronizing reagent and RE types, the depth of boronizing layer was selected as main evaluation parameter through the orthogonal test of RE-boronizing. Experimental results show that, cerium oxide with particle size of 20nm and content of 4% has the best effect of accelerating boronizing process on 65Mn steel at 700°C for 9 h, and the depth of boronizing layer with RE-boronizing is about 3.3 times than without adding RE; meanwhile, the heart of 65Mn steel still keeps good strength and toughness due to temper troostite microstructure. It can be concluded that the strengthening and toughening treatment of low-temperature RE-boronizing can obtain hard-surface and tough-core properties on 65Mn steel.
Analysis on Fracture Mechanism of T92 Steel under High Temperature Multiaxial Creep
Authors: Xu Hong , Yuan Jun , Liu Jing , Huang Sai Dong , Li Chao , Wang Xiao , Yu Yang , Mao Xue Ping
Published: June 2014

The high temperature creep tests of standard specimen and double U-notched specimen of T92 steel were carried out under different stresses at 600°C and 650 °C. Then scanning electron microscopy was used to observe the fracture morphology. The results show that the notch weakens plasticity, and weakening with the notch acuity. Under multiaxial stress state, the failure mode of T92 steel gradually transfers from ductile dimple to brittle quasi-cleavage fracture. Compared with uniaxial stress state, the dimples under multiaxial stress state are smaller and shallower, within lots of carbides and second phase particles. The notch slows the connection, growth and gather of microvoids, and exhibits notch strengthening effect.
Piston Contact Stress Analysis and Simulation
Authors: Jiang Fan
Published: June 2014

Contact stress and Pull-out stress formatted by piston and the valve seat directly affects the piston seal and friction wear performance. It is of great realistic significance to study on distribution of the contact stress and the assembly relationship between piston and valve seat. Finite element analysis methods were used to obtain the distribution of the contact stress in static and dynamic conditions. Problem of piston size selection was analyzed between different assembly interferences. Simulation results indicate that contact surface average Mises stress of valve seat was about equal to yield strength of materials with interference in 0.01mm; while in conditions of interference in 0.02mm and 0.03mm; radial deformation of valve seat was obvious. Based on analysis and considering mechanical properties of materials, unilateral interference between piston and seat would not exceed 0.01mm; when friction coefficient was defined as 0.05 and unilateral interference was set as 0.01mm, output stress would be 892.14N, which far less than hydraulic pressure arising from pull-out stress who would only be 300N. Therefore, 0.01mm unilateral interference can completely meet the use requirements.
Development and Change of Compressive Strength for Class G Oil Well Cement under High Temperature
Authors: Zhang Jing Fu , Liu Kai , Hou Rui Xue , Wang Bo , Yang Jin Long
Published: June 2014

The compressive strength of oil well cement would be damaged by high temperature in deep oil wells, which was caused by the obvious change of the components and microstructure of cement hydration products. The adaptability of common oil well cement for cementing under higher temperatures was confined by above reasons. Characteristics of development and change of compressive strength of Class G oil well cement were studied under different temperatures by using Static Gel Strength Analyzer and High Temperature-High Pressure curing chamber. The influence law of temperature and silica sands on compressive strength was analyzed. The results showed that the critical temperatures at which the compressive strength begun to decline were about 110°C and 150°C respectively; The compressive strength increased with curing time during the initial period and would reduced after it reached a certain value when temperature exceeded 110°C; For cement with silica sands, the compressive strength development trend was in the shape of two-stage form with increase of curing time within the range of 110~150°C, but for 160~200°C temperature range the development form was in the shape of single stage; The reasonable amounts of silica sands which would be added to cement slurry to enhance the compressive strength of hardening paste were determined to be 30%~40%.
Effect of True Strain on Processing Maps for Processed Ni-Based Superalloy below γ΄-Transus Temperature
Authors: Yang Guo Bao , Yao Ze Kun , Liu Yan Hui , Nan Yang , Ning Yong Quan
Published: June 2014

Isothermal compression tests were carried out on GH4133B superalloy at 940–1060°C (below nominal γ΄-transus temperature of 1080°C) and 0.001–1.0s-1. The processing maps were constructed to evaluate the efficiency of power dissipation (η) and recognize the flow instability regimes. Our investigations demonstrate that true strain takes great effect on processing maps' evolution. At 1020°C/1.0s-1, the efficiency valueηundergoes a small decline at low strains, and then increases linearly from 0.26 to 0.58 at high strains. However, the efficiency value remains high constant (η=0.40) with the increased strain under the condition of 980°C/0.001s-1. As a result, hot deformation can be carried out firstly at 980°C/0.001s-1with small strain about 0.35 and then carried out at 1020°C/1.0s-1to get fine homogeneous microstructure. There are two instability regimes respectively located around 940°C/1.0s-1and 1060°C/0.001s-1when the strains are 0.05–0.40. Moreover, there is another instability regime located around 1060°C/1.0s-1when the strains are 0.45–0.69.
Multiscale Simulation of Crack Propagation Based on Molecular Dynamics
Authors: Bian Gui Xue , Chen Yue Liang , Zhang Yong , Yu Da Zhao
Published: June 2014

A multiscale simulation approach is developed to investigate mechanism of crack propagation from the atomistic perspective. The finite elements (FE) method has been applied to obtain displacement load of the model. The quadrangle region around the crack tip crack tip has been prepared for the molecular dynamics (MD) model. The displacement load calculated by FE was applied to boundaries of the MD model. The simulation results show that the evolution of atomic configuration of the system includes dislocation emission, atomic disorder, atom bond rupture and microcrack propagation.
Evaluation of Mechanical Properties of Hastelloy C-276 Weld by Small Punch Test
Authors: Ma Yan , Xu Yan Ze , Zhang Shu Yu , Lu Chen Lin
Published: June 2014

Mechanical properties of the electron beam weld zone, which are different from the base metal, of Hastelloy C-276 were studied by small punch test (SPT) technology. Load–displacement curves and material properties were obtained by using miniaturized plate-type specimens (3mm diameter×(0.15-0.4) mm thick) from the weld and base metal respectively. The result shows that the maximum load of weld is larger than that of the base metal under the same thickness, meaning the higher strength of the weld. Furthermore, finite element method analysis was performed to investigate the effects of specimen thickness, the diameter of loading ball and the diameter of center hole in holder on the plastic damage of Hastelloy C-276.
Prediction of Flow Stress for Superplastic Tension Deformation
Authors: Guan Zhi Ping , Ren Ming Wen , Ma Pin Kui , Zhao Po
Published: June 2014

With the development of numerical calculation and precision forming, constitutive equations are required to possess high accuracy and good reliability, rather than simplicity of mathematical form. Due to simple algorithm and constant parameters, the conventional constitutive models can not be suited to describing superplastic flow behavior which represents complex responses with a large strain. In this study, through surface fitting on experimental data from tension tests performed over a wide range of strain rates, tensile velocities and loads, an empirical approach was proposed to establish constitutive equation for complex superplastic behavior of Zn-5%Al alloy at 340 °C. The empirical constitutive equation not only represents the strain dependence and the strain rate dependence of stress, but also reflects the coupling effects of strain and strain rate on stress, which can not be achieved by traditional models. A comparison between the predicted flow stresses and the experimental data verified that the empirical constitutive equation has high accuracy and good reliability on modeling superplastic flow behavior of Zn-5%Al alloy at 340 °C in a wide range of strains 0~2.5 and strain rates 7.0×10-5~8.0×10-2s-1.
Quantitative Analysis of Instability for Superplastic Tension
Authors: Guan Zhi Ping , Ren Ming Wen , Ma Pin Kui , Zhao Po
Published: June 2014

In conventional analysis of instability, a rough prediction of uniform deformation was obtained due to taking material parameters as constants. In this study, the constitutive equation with varying parameters for Zn-5%Al alloy at 340 °C is employed to predict the critical values of uniform strain in tension based on Considere criterion and Hart criterion, respectively. It should address the factor of strain rate in the characterization of the capability of uniform deformation on superplastic alloys, or for that matter, on any rate-dependent material. Comparison and analysis indicated that the results on Hart criterion have the better predictability of uniform deformation than Considere criterion. The Considere criterion is dependent on strain path, while Hart crtierion is merely dependent on the values of strain and strain rate in tension, and is independent on the strain path or the deformation condition or the deformation history. Therefore, the uniform strain vs. strain rate relation can be taken as a quantitative reference for designing a reasonable strain path during superplastic forming with increase of formability and reduction of forming time.
Texture Evolution of Commercially Pure Copper during Ultra-Thin Strip Rolling
Authors: Song Meng , Liu Xiang Hua , Tang De Lin
Published: June 2014

Experimental investigation on rolling texture evolution in commercially pure copper thinned from 5.8mm to 20μm by symmetrical rolling and asymmetrical rolling without annealing were carried out via orientation distribution functions and orientation line analysis. The results show that the rolling texture for the sample with initial rotate cube texture {100}<011>mainly consist of C and B, most crystallites aggregate along the α and β orientations lines. The texture density growth rate increased significantly in rolling process. That may relate to size effect of ultra-thin strip. The rate of dislocation reduction was more than dislocation multiplication due to disappear at grain size, when the thickness of ultra-thin strip decreased to an extremely value.
Calculating Fatigue Life of Helicopter Composite Blades Based on the Residual Strength Theory
Authors: Wang Wei , Zhu Yu Lin , Xiao Qi Min
Published: June 2014

This paper presents a method for calculating the fatigue life of helicopter composite material blade with residual strength theory. Builded the residual strength model, analyzed the influence of loading sequence, tensile -- compressed between the conversion and failure probability, adopt corresponding treatment plan. Using the model of residual strength, selected 19 typical flight condition, using the "rain flow counting method" load matrix, finally get the helicopter load spectrum. The composite blade dangerous section are calculated (root maximum strain), combined with every moment and centrifugal force, the flight state determined blade the stress spectrum, then according to the blade model and material characteristic parameters were calculated, results show that the residual strength decreases with the increase of flight time, and the failure probability increased with the flight time increasing. By comparison, the calculation results and full size is consistent with the experimental results, which shows the calculation is reliable.
Research on Grind-Hardening Process through Integration of Physical Experiments and Dynamic Simulation
Authors: Han Zheng Tong , Yang Gang , Luo Hong Bo
Published: June 2014

Grind-hardening experiments of 40Cr steel were carried out on the external grinder, and the hardness and hardened-depth of the samples were measured and analyzed. Experimental results showed that the external grind-hardening was feasible and could take the place of high-frequency induction hardening. Moreover, dynamic temperature field was simulated and analyzed based on the finite element analysis, and the simulation results were in a good accordance with these of experiment values.
Preparation and Characterization Composite Ceramic Coating Doped with ZrO2 Particles on TC4 by MAO
Authors: Zhong Ye Sheng , Shi Li Ping , Li Ming Wei , Yu Jia , Liang Jian Han , Sun Ming Bo , He Xiao Dong
Published: June 2014

A numerical study using finite element analysis (FEA) was performed to investigate the thermal, shear and radial stresses developed in MAO coating on substrate of TC4 under thermal cycle loading. The four-node quadrilateral thermal solid element PLANE55 and four-node quadrilateral structural solid element PLANE42 with axisymmetric option was used to model the temperature distribution and thermal stress field of the MAO coating on TC4 substrates. The thermal stress, radial stress and shear stress along the thickness in film/substrate system are analyzed systematically under different thermal cycle loading. It is found that the thermal stress of MAO coating exhibits a linear relationship with thickness of substrate, but it exhibit a parabolic relationship with the thickness of the coating. The radial stress and shear stress distribution of the coating–substrate combination are also calculated. It is observed that high tensile shear stress of MAO coating on TC4 substrate reduces its adhesive strength but high-compressive shear stress improves its adhesive strength.
Preparation and Characterization of Al(OH)3 Coated CaF2 Composite Powder
Authors: Li Ming , Xu Chong Hai , Chen Zhao Qiang , Xiao Guang Chun , Chu Guang Chao
Published: June 2014

Al (OH)3 coated CaF2 composite powder was prepared by coating Al (OH)3 on surface of micro-sized CaF2 particles using heterogeneous nucleation method. Influence of Al3+ concentration, PH value and reaction temperature was studied. The result reveals that CaF2 particle was uniformly coated with a layer of Al (OH)3 and Al3+ concentration, pH value and reaction temperature are the main factors that affect coating result. Optimum technological conditions are Al3+ concentration of solution before reaction at 0.15 mol/L, pH value at 7.5 and temperature at 75 oC.
Progress in Thermal Barrier Coatings for Gas Turbine Engines
Authors: Wang Hong Xun , Zhang Wei Fang , Liu Tian Jiao
Published: June 2014

In recent years, the key research on thermal barrier coatings (TBCs) lies in the performance improvement of materials as well as structure and process improvement, and achieves new progresses. The difficulty is application of reliability in TBCs. Researchers are exploring that employing non-destructive testing (NDT) and life prediction model on TBCs to conduct a comprehensive and real-time detection and predict the life, so as to improve the safety of TBCs in service process.
Research on the Corrosive Factors of Q235 Steel in Simulate Ammonium Sulfate Solution of Ammonia Desulphurization
Authors: He Lian , Chen Dong Sheng , Lou Fei Fei , Ye Qin Qin , Wei Wu Ji , Zhou Yong Zhang
Published: June 2014

Corrosion behaviors of Q235 steel in simulate ammonium sulfate solution were studied. Effects of the ammonium sulfate concentration, Cl- concentration, pH and the flow velocity on corrosion of Q235 steel in simulate ammonium sulfate solution were investigated by the weight-loss method, and the electrode processes were studied by polarization curves. The result showed that: (1) the corrosion rate of Q235 steel increased with the increase of Cl- concentration firstly. When Cl- concentration was 10000ppm, the corrosion rate reached the maximum value of 6.698 mm/a, and then, with the increase of Cl- concentration, the corrosion rate decreased. (2)With pH increasing, the corrosion rate of Q235 steel decreased. (3)The corrosion rate increased with the increase of the concentration of ammonium sulfate firstly. When the concentration of ammonium sulfate was 5%, the corrosion rate reached the maximum value of 5.462 mm/a. And then the corrosion rate decreased. (4)The influence of the flow velocity on Q235 steel corrosion was remarkable, with the increase of the flow velocity, the corrosion rate increased rapidly.
Numerical and Experimental Investigation on Hot Stamping of Ultra-High Strength Steel
Authors: Xu Hong , Zhang Mou Rui , Zhu Li Juan
Published: June 2014

In the automotive industry, hot stamping of ultra-high strength steel offers the possibility to reduce vehicle weight and enhance safety performance. However, the imperfect technology restricts its application. To investigate the hot stamping technology further, numerical simulation and forming experiment were made in this paper with a door beam as an example. After process parameters analysis, the evolution of sheet during the whole process were predicted through the simulation, according which the microstructure of the part were full martensite and no fracture was produced. A door beam was well-formed in the experiment based on the results of simulation, and then a series of tests as metallographic observation, hardness test, tensile test and side impact test were carried out, studying its performance in practice.
Development of Environmentally Friendly Binder in Extrusion Molding
Authors: Meng Xiao Wei
Published: June 2014

A new kind of binder was developed in extrusion molding. It included four ingredients: ethylene glycol acetate (60%~85% (mass/mass, as follows)), ethyl cellulose (10%~30%), ethylene glycol polyoxyethylene ether (5%~10%), polyethylene glycol stearate (0.8%~3%). The components of binder were compatible with thermodynamic conditions, so the binder was well-distributed in molecule level. The new binder is actual nontoxic, secure and environmentally friendly. The forming property of the binder is so excellent that it can load 54% ~ 56% (vol. /vol.) cemented carbide powders. The rods produced by this new binder provide high strength, stable performance, homogeneous microstructure.
Optimization Design of Evaporator Tube Plate Mold Based on PDX
Authors: Gao Zhang Yu , Chen Hui , Zhang Yan Jie , Li Shi Nan , Yu Hong Mei , Xu Wei , Yu Lu Ning
Published: June 2014

Current tube plate stamping die usually have some common problems, which include low standardization, low standard penetration and long mold design cycle. By analyzing stamping die used in the refrigeration industry, the cold-drawing dies blanking needs to be designed and optimized. Compared with the previous design methods, the method, that the Pro/E plug-PDX was used to design cold-drawing dies blanking with refrigeration equipment, has a lot of advantages. First, cycle was shortened to one-third of the original; second, the compound pressing method is able to reduce the pressing step and increase stripping device, in order to improve the reasonable structure and production efficiency. The new method proposed in this paper is able to increase design efficiency, shorten design cycles, reduce workload and improve the accuracy of the mold design, and reduce the cost of mold design.
Study of Submacroscopic Melting of Polymer in Single Screw Extrusion - Physical Model of Polymer Granule Melting
Authors: He Hong , He Jian Yun , Liu Yong
Published: June 2014

The process of polymer melting plays a vital role in stable extrusion. Due to its complexity in “a black box”---extruder, it is difficult to observe directly. Therefore, the visualization technology applied in this course emerged and has been improved continuously, which is regarded as an important means of promoting the development of extrusion theory. This article describes and analyses the phenomena of bulk melting and granule melting with the aid of the submarco-and macro-scopic visual technique in single screw extrusion. Physical model of granule initial melting in extrusion was presented.
Study on the Influence of Thickness and Width on the Post-Buckling Deformation of Cold-Rolled Strip
Authors: Wang Dong Cheng , Zhou Xue Feng , Liu Hong Min
Published: June 2014

As a consequence of post-buckling due to high residual stresses caused by the cold-rolling process, long free thin strips frequently show excessive wavy surface. In this paper, a new analytical approach by extending a classic post-buckling analysis method based on the minimum potential energy principle is used to study on the influence of strip thickness and width on the post-buckling deformation for the center and edge wave. It is concluded that the thickness of the strip has significant effect on the flatness defects, while the width does not.
Research and Application of Basic Tundish Covering Flux
Authors: Yang Zhi Zheng , Li Gang Qiang , Rao Jiang Ping , Wang Yan Feng , Huang Cheng Hong , Hong Xia
Published: June 2014

The elementary theory of functions of the basic tundish coving flux is analyzed at the beginning of this paper. Several types of the flux used in deferent steel grade include ultra-low carbon steel, low carbon steel and micro-alloyed steel. The result shows that the basic flux with CaO/SiO2 to be 3~5 can help to control the SiO2 be reduced by Al in steel within ±2%, and whole cleaness keeps stable with suitable component and proper process condition, marked with the T[O] content change ranged within 3ppm. But the basicity should be variable considering the productivity for different steel grade.
Surface Characterization and Machinability of Zirconium Alloys in View of Jewelry Application
Authors: Forno Ilaria , Priarone Paolo C. , Settineri Luca , Actis Grande Marco
Published: June 2014

The jewelry making has been traditionally considered handcrafted and hinged on the ability of goldsmiths to create components and assemblies. In recent years, however, a profound transformation has begun, driven by the global markets requiring robust engineering approaches to the analysis of new materials and of product/process optimization. Moreover, gold and silver were conventionally associated to the jewelry production, but the use of materials other than precious metals (such as steels, titanium alloys, woods and ceramics) is nowadays a standard for many companies. In this context, the research activities presented and described in this paper focus on the performance evaluation of a Zirconium alloy, in terms of material properties and machinability, for the application in the jewelry industry. Perspiration, salt spray and abrasion tests provided results comparable or even superior to those typical of a Ti-6Al-4V alloy, especially in case a Zirconia layer is induced on the Zirconium alloy through a properly designed oxidizing treatment. Machinability can be performed with conventional tools and equipment, and the production route of jewel prototypes is detailed.
Large Container End Plate Stretch Forming Technology
Authors: Mao Kun Li
Published: June 2014

End plate of some large container is of non-conventional type and rather large size, which is difficult to be formed. To choose fit technology parameters and mould structure, stress is analyzed and bending of shallow stretch forming rule is obeyed. Technology of large container end plate stretch forming in 500 tons oil hydraulic press is researched and one mould manufacturing method is given fit for shallow stretch forming. In this technology, to form convex bottom and improve strength, material-pressure plate is not adopted. To reduce wrinkle and stretch force, 30 degree cone of cavity die is selected. To reduce bending deformation and destabilization, round radius of male punch is 8 millimeters.
Oval Aluminum Tube Extrusion Process Simulation with Two-Hole Dies
Authors: Miao Cong , Yang Hai Bo
Published: June 2014

In this paper, the process of two-hole dies extrusion oval aluminium tube simulation analysis is carried out by the Deform-3D software .The simulation includes blank shunt, welding and extrusion deformation process. Temperature and stress distributions of the extrusion deformation is obtained through the simulation. It reveals the key factors of the two-hole dies extrusion forming stably, that is when the metal extrusion die holes, two holes each particle extrusion speed differences within a reasonable range, the extruded profile can stably forming. Putting forward the key factors theory of two-hole dies of aluminum profile extrusion forming stably provides a theoretical guidance for the production of aluminum production with multi-hole dies.
Problems of Cold-Bent Notched C-Shaped Profile Members
Authors: Vatin Nikolay I. , Nazmeeva Tatiana , Guslinscky Roman
Published: June 2014

Nowadays cold bent steel thermal сold-bent С-profile is widely used in building construction but we still have some little studied questions in the fields of thermal conductivity, air permeability, resistibility and corrosion behavior of the profile. Cold-bent notched С-profile is used for interior exterior panel members. Lengthwise notches made chequerwise in the profile walls increase the distance of heat flow and decrease heat conductivity and eliminate cold bridges that is why the profile is called “thermal profile”. Cold-bent profile made by cold bending requires alternate approach when engineering structures are designed and maintained. The approach means thin walls’ and the profile special form’ impact on the bearing capacity and stability of the structures should be taken into account. In spite of the wide use of cold-bent notched C-profile in building frameworks, we see lack of information on how the notches influence the bearing capacity and stability of structures. There are no official normative documents on calculation and designing of cold-bent notched profile structures. We carry out theoretical and experimental investigations on global buckling and bearing capacity of steel members of C-shaped notched profiles of different cross-sections area. We carry out theoretical and experimental investigations on heat current passing through the thermal profile structure is held with the use of testing bed.
Simulation to the Temperature Field for Continuous Casting Billet during Direct Rolling of Free-Heating
Authors: Luo Guang Zheng , Liu Xin , Zhi Ying , Liu Xiang Hua
Published: June 2014

The temperature field of continuous casting billet (CC-billet) is important to carry out the research on direct rolling of free-heating (DROF). The solidification and the heat transfer process of CC-billet from crystallizer to cutting point were studied by finite element method (FEM).The casting speed was improved in order to get reasonable temperature field during DROF.
The Strain Analysis of Plate Cross Wedge Rolling of Spiral Shaft Parts
Authors: Shen Fa , Yu Wen Jing , Peng Wen Fei , Shu Xue Dao , Yu Chun Jie
Published: June 2014

The spiral shaft parts have been widely applied in machinery and equipment manufacturing industry, the paper based on DEFORM-3D, the rigid-plastic finite element model of cross wedge rolled spiral shaft parts was established. The rolling process was simulated, the strain laws were analyzed, and the characteristics of metal flow were explored. From which we can find Plate cross wedge rolled spiral shaft parts is completely feasible. The results provide the theoretic basis for precision deformation of cross wedge rolled spiral shaft parts.
Arc Characteristics and Droplet Transfer Analysis of Disconnect Impulse Arc Welding for Repairing Surface Default of Metal Parts
Authors: Yang Jun Wei , Teng Jia Xu , Zhang Qing , Meng Ling Dong
Published: June 2014

The wire material and the workpiece was fused together by the transient arc heat from disconnect impulse, to achieve metallurgical bonding. The process of arc striking and the arc was very short in disconnect impulse arc welding. The image signals of disconnect impulse arc and droplet transfer were acquired using speed camera systems. Then, the arc and the droplet transfer characteristics in repairing the metal defects process were discussed. The results showed that the process of arc striking was only 0.5-1ms in disconnect impulse arc welding. The maintain arc time must be matched with the arc current, the longer maintain arc time the less the arc current was likely to be.
The Effect of Joule Heat on Coupling Temperature Field of Friction Stir Welding
Authors: Yang Jie , Dong Lin , Tian Xing Chun
Published: June 2014

Based on the friction stir welding rig,the temperature field model was established by COMSOL Multiphysics under the coupling effect of joule-heat and friction heat. The coupled temperature field distribution and variation rule of the analysis model were simulated and analyzed under current-carrying or without current. The results show that the maximum temperature mainly distributes the contact area of the pin tool and work piece. The distribution of the temperature and isothermal layer with current is basically same with non current. The temperature distribution area of shoulder with current gets larger than without current condition. Under the constant welding velocity,axial force,rotation velocity and displacement,the maximum temperature produced by coupling function of joule-heat and friction heat is much higher than the one,which engendered by friction heat.
Experimental Research of Activating Fluxes in A-TIG Welding of 5052 Aluminum Alloy
Authors: Zhou Ze Jie , Huang Zhi Chao
Published: June 2014

AC A-TIG welding on 5052 aluminum alloy was investigated. The single component of oxide TiO2, SiO2, Cr2O3, V2O5 and halide CaF2 was served as activating fluxes to study the effect on weld penetration and weld forming. The experimental results show that weld penetration can be increased and welding productivity can be improved in A-TIG welding. Activating fluxes, especially TiO2 and SiO2, have more significant effect on weld penetration than conventional TIG welding, moreover the better weld shape formed after coating activating flux is obtained, weld width has slight decrease that makes HAZ of A-TIG welding smaller.
Relationship between the Microstructure of the Welded Steel Plates and the Efficiency of Vibration Stress Relief
Authors: Li Shu Qi , Fang Hong Yuan , Liu Xue Song , Cui Wei
Published: June 2014

Welded components of low alloy steels are widely used in various applications. Stress reliving is very important to these welded structures. Vibration stress relief (VSR) is an relatively new method for this purpose. In this study, Q235 and Q345 steel plates were welded. Then they were treated by VSR. The microstructure of the welded lines were investigated and the residual stresses in two directions in these welded structures were measured. The difference of the efficiency of VSR on the two materials were investigate. It is found that, the decreasing amplitude of the residual stress in the Q235 welded structures significantly exceeded that in the Q345 welded structures. The grain size in the area near the weld lines is the main factor that affects the efficiency of the VSR treatment.
The Implementation of Martensitic Heat-Resistant Steel Welding Performance Analysis and Process
Authors: Xia Hong Liang
Published: June 2014

This paper mainly introduces the properties of welded joints of supercritical boilers, combined with the actual construction of a power plant, of these new type heat-resistant steel we Ultra supercritical unit; heat resistant steel; weldability al exploration.
Model Structure and Simulation Analysis of a Novel Magetic Suspension Spindle Apparatus for Micro EDM
Authors: Guo Yong Feng , Ling Ze Bin , Zhang Kai , Feng Ye Rui
Published: June 2014

In the Micro Electronic Discharge Manufacture (The diameter of electrode is no more than 0.5mm), the response frequency of the spindle in Z axis is too low to satisfy the requirement of rapid response. Considering this problem, a novel spindle apparatus based on the Magnetic Suspension drive principle is proposed in this paper, the basic structure and principle are introduced. At the same time, the Magnetic field distribution and they are analyzed by the finite element software Ansoft Maxwell. Theory conduction and simulation results indicates that the response frequency of the spindle and the electromagnetic forces satisfy the design requirement, the novel spindle can shift in a small range around the equilibrium position, and there is no magnetic coupling effect in each other degrees of freedom of the spindle, so the independent PID algorithm can be used in the control of each degree.
Microfluidic Chips with Micro-Pillar Array for Cell Capture
Authors: Lai Tao , Wang Guang Long , Gao Feng Qi
Published: June 2014

Microfluidic chips with micro-pillar array to capture cancer cells in a small volume were designed and fabricated in this paper. The structure includes two parts. This chip has a glass slide bonded to a silicon structure, and both of them contain twelve micro-channels with patterned chevrons or U-triangle-bones, micro-pillar array is completed on silicon wafers using wet chemical etching method on the substrate. To monitor cell capture tendency of the structure, the rows of capture structure were modeled using the finite element method (COMSOL Multiphysics). The results show that this structure can decrease the impact force to half or even less, the fluid can go through the micro-pillar array equably and the subjects in the flow can be sizing by the structure.
Study of Effect of Laser Marking Data Matrix Symbols on Titanium Alloy Sheets Using Nd:YAG Laser
Authors: Li Chun Ling
Published: June 2014

Laser direct-part marking is finding increasing use in the tracking of products as they pass through a manufacturing process. But too high heat input of the laser may cause deformation of the product beyond the limit of the drawing. In order to investigate the effect of laser marked Data Matrix symbol on titanium alloy, a Q-switched lamp pumped Nd:YAG laser was used in this research. Two Data Matrix symbols using 16A and 28A of electric current were marked respectively in the center of two titanium alloy sheets with 50mm length and 50mm width and 2mm thickness. To analyze the quality of the laser marking, environmental scanning electron microscope (ESEM) and X-ray diffractometer (XRD) were used. Experimental results showed the HAN’S Q-switched lamp pumped Nd:YAG laser marking system did not cause damage to the titanium alloy.
Efficient Genetic Algorithms for Measurement of Flatness Error and Development of Flatness Plane Based on Minimum Zone Method
Authors: Ilyas Khan Muhammad , Ma Shu Yuan
Published: June 2014

Measurement of geometrical tolerances is one of the prime processes in manufacturing for ensuring the quality of the machined components. Manufactured components are sent to assembly line based on measurement reports, so measurement is inevitable in any production setup. Flatness error is one of the important icons in the crew of geometrical tolerances; if unqualified components are sent to assembly line, the components may not function according to the design requirements. This paper presents real coded efficient genetic algorithms (EGA) for flatness error measurement and flatness plane development using minimum zone method. Flatness plane has been developed by determining the flatness plane coefficients. The flatness plane coefficients determine the orientation of the surface. The proposed algorithms are equipped with high precision, accuracy, good repeatability and fast mature convergence rate. The algorithms characteristics like precision, accuracy, repeatability ensure the reliability of measurement results of measured component and fast mature convergence rate ensure the reduction in the inspection time.
Mathematical Model of Topology Modification of Tooth Surface and Error Characteristics
Authors: Wang Hui Liang , Deng Xiao Zhong , Yang Jian Jun , Xu Kai
Published: June 2014

In order to analysis the processing performance of the CNC grinding machine, the master profile error distribution characteristics of gear grinding tooth error analysis method based on statistical process control techniques. Tooth profile error topology control charts, analysis of the tooth length direction and the tooth height direction of the error distribution, respectively, corresponding to establish the mean - range control chart. Control charts to achieve real-time distribution of the gear grinding process tooth profile error, error change trend analysis and prevention. Calculate the machine's process capability index, derived CNC grinding processes. Finally, analysis the main causes of tooth profile error and take appropriate measures to reduce the tooth profile error by the cause and effect diagram.
Computational Solution of Contact Problems with Unilateral Constraints and Friction by Step-by-Step Analysis
Authors: Lukashevich Anatoly
Published: June 2014

Here computational models of contact of elastic systems with the contact finite elements (CFE) in a 2D or 3D frame-rod systems are reviewed. The solution is based on the method of the step-by-step analysis taking into account the character of loading, the complicated conditions of the contact and other factors consideration of which approaches the calculation circuit of the task to the real operating conditions of any structures or construction
Influence of Cold-Rolled Strip Temperature on the Interference Fit of Entire Roller Embedded Shapemeter Roll
Authors: Wu Hai Miao , Liu Hong Min
Published: June 2014

For entire roller embedded shapemeter roll, the temperature differences and radial relative displacements of contact node pairs on the interference fit surface between the framework’s top surface and roll body’s inner hole surface, and the sensor pre-pressure were analyzed using the finite element technology in cold reversible rolling passes. The influences of temperature differences on radius relative displacements of the contact node pairs and the sensor pre-pressure were obtained. The results show that the maximum temperature difference of the contact node pair occurs in the third rolling pass, and most of radial relative displacements of contact node pairs exceed the value of interference fit, which makes the sensor pre-pressure be close to zero. So the transfer of pressure that the strip applied on the outer surface of shapemeter roll is seriously affected, and the shape measuring signal is interrupted.
The Inverse Prediction for Profile Extrusion Die Based on the Finite Element Method
Authors: Zhang Min , Huang Chuan Zhen , Jia Yu Xi , Liu Jin Long
Published: June 2014

Considering the extrudate swell, the polymer extrusion process was calculated by the inversed simulation based on the visco-elastic ecology theory. The fluid characteristics of the polymer melt were described by the Phan-Thien and Tanner (PTT) model. The Finite Element Method was used. Based on the simulation data, the extrusion die lips were analyzed. So it is feasible to design the polymer extrusion die lips using inversed simulation method.
The Influence from the Return Water Temperature of Condenser on the Cooling Capacity and Power Consumption of the Cold-Water Screw Unit Used on Cold Storage
Authors: Ding Zhao Lei , Li Feng Tong , Zhang Chang Feng
Published: June 2014

The mathematical models of the cold-water screw unit used on cold storage has been established.The operating condition of the unit which working at partial load has been simulated,with different return water temperature of condenser.The influence from the return water temperature of condenser on the cooling capacity and power consumption on the condition of different capacity of compressor has been analyzed, when the evaporation temperature is-10°C.The fact that the operational cost can be significantly reduced if the night cool storage technology is adopted.
Application of Thermal Contact Resistance in Simulation of Heat Dissipation by CPU Heat Sinks Based on ANSYS
Authors: Liu Yong Zhen , Huang Zhi Shi , Feng Bin , Wei Jin He , Zeng Jian Min
Published: June 2014

With development in electronic technology, more and more electronic elements have been integrated into one chip, which has resulted in the cooling problem of the chips. In this case, heat dissipation has become the main factor that affecting the design reliability and package cost. Therefore, good heat dissipation designs are urgently need to solve the problem. An important issue resulted from simulation of heat dissipation is the determination of boundary condition between the heat sink and the CPU. The concept of thermal contact resistance was introduced to simulation of heat dissipation of CPU heat sinks in this paper. The temperature distribution of CPU heat sinks was calculated Based on ANSYS software. The result of calculation can help to understand the heat transfer characteristics of CPU heat sinks, and also offer a reference for the design and improvement of the electronic equipment.
The Influence of the Position of the Steel Element to Heat Flow in the Wall of the Industrial Freezer
Authors: Mohapl Martin , Vojkůvková Petra
Published: June 2014

This contribution defines physical heat behaving of a selected construction part of a wall in an industrial freezer. This study is focused on the specific selected example of possible solution of the connection between the insulated wall and a load-bearing rolled steel I-shaped beam. The aim of this study characterizes the impact on thermal losses of exchanging coldness and the field of temperatures in different variants of the selected element installation based on executive parametrical simulations. This article also shows thermo-graphical measuring and monitoring of the element and describes possible risks of the real selected solution.
Theoretical Analysis and Experimental Study on Heat-Transfer in Cryogenic Gas Atomization Jet Cooling Nickel-Base Alloy
Authors: Guan Xiao Yan , Wu Ai Sheng
Published: June 2014

Based on pool film boiling, Heat transfer coefficient and cooling model are established when fogdrop jet into cutting zone to cool high temperature wall. Through the transient experiment of cryogenic gas atomization jet cool high temperature nickel-base alloy surface with different water dose. The water dose achieving the best cooling effect is 2 ml/min, 4ml/minand 6ml/min under the nickel-base alloy surface temperature at 300 ℃, 500 ℃and 650 ℃. Then the effect of water density to heat transfer coefficient is discussed. Water dose to the best cooling effect must be equivalent to the amount of water that materials can vaporize and participate in the phase-change heat transfer under certain temperature. When achieving optimal cooling effect, the number of fogdrops participating in phase-change heat transfer are the most , and heat transfer coefficient reaches the maximum.
Change Regulation of Hardness of Target around Crater Penetrated by Wf/Zr-Based Amorphous Matrix Composite Projectile
Authors: Ye Xiang Hai , Shi Hong Gang , Zou Min Ming , Tian Kai Wen , Liu Jin Bo , Zhu Li Jun , Zhang Zhong Ya , Wang Qun
Published: June 2014

Because of excellent mechanical, physical and chemical property Wf/Zr-based amorphous matrix composite attracts people’s interest and becomes the hot spot of science study and engineering application. In this paper, change regulation of hardness of target around crater by Wf/Zr-based amorphous matrix composite projectile and its mechanism are studied after firing test, and it is found that the section can be divided into 3 layers: the Martensite layer, the deformed fine grain layer and the normal matrix from the crater surface to the interior of the steel target and that the thickness of Martensite layer increases first and then decreases in the penetration direction when the velocity of projectile is 1200m/s.
Hydraulic Fracturing Technology Design in Natural Fracture Reservoirs
Authors: Cai Bo , Ding Yun Hong , Cui Zhou Qi , Yang Zhen Zhou , Shen Hua
Published: June 2014

Nowadays, hydraulic fracturing has become the mainly treatment in low permeability reservoirs, but the hydraulic fracturing design technology in different reservoirs still use common methods. Natural fracture reservoirs mainly include granite reservoir, basalt reservoir and igneous rock reservoir which its hydrocarbon pore volume is fracture system. As the existing of natural fracture, hydraulic fracturing treatment always counting some problems, such as difficult sand pumping, easily screen-out and limited scale. In this paper, from the point of the reservoir characteristics, the mainly problems were analyzed and the corresponding methods were put forward .the core technique in this kind reservoir include communicating the distance nature fracture and meanwhile protecting the conductivity nature fracture. Production can reach 90% from natural fractures using numerical simulation.
Study on Floor Pressure Relief Law of Simultaneous Mining Working Faces in close Distance Seam Group of Dongsheng Coalfield
Authors: Chen De Ming , Zhang Chun Lei
Published: June 2014

In order to research floor pressure relief law of shallowly buried descending coal-mining working face covered with thin soft bedrock in Dongsheng coalfield , taking Lijiahao coal mine for example, firstly, to calculate the impact depth was 18.86m by the theoretical formula, then analyzing coal and rock mass stress and displacement variation of the upper work surface to its floor during mining based on numerical simulation. Obtaining coal and rock pressure relief depth of the floor was 70m, with the working face advancing, the pressure relief depth and range became larger, to achieve stable at a certain number;affected by the mining of 2-2 coal, coal and rock mass strength of its floor was weak, the largest damage depth was about 18m,this result would provide a basis to the roadway of the 3-1 coal in different coal pitch; affected by the mining, the goaf overburden and floor of 2-2 coal working face appeared "O" shape fracture zone, the floor rock fissure of 2-2 coal got through to the roof of 3-1 coal,cracks formed transfixion,which made the pressure change of 3-1 coal working face, Mine pressure appearance tended to be ease, it would be easily control if the roadway of 3-1 coal was arranged in the area of pressure relief. The theoretical results would be useful to actual production.