Table of Content

10 May 2013, Volume 24 Issue 09

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Cathode Design and Experiments on Radial Feeding in ECM of Blisk Based on Cascade Channel Machinability Analysis

SUN Lun-Ye, XU Zheng-Yang, SHU Di

2013, 24(09):  1137-1141. 

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In order to improve the processing quality of cascade channel, a method of ECM with cathode radial feed was proposed. The machinability of the cascade channel was analyzed, boundary surfaces of the channel which can be processed were acquired by the data processing on the cascade channel model, the impact of different machining angles on the channel surface margin was analyzed to determine the reasonable feed direction. The side profile and end surface of cathode were designed on the basis of model analysis, the tool cathode was prepared subsequently. To verify the correctness of the cathode design proposed, the experimental investigations were carried out and the results reveal that the wheel hub can be machined with good accuracy, the processing quality in the blade root is improved, the margin distribution of channel surfaces is uniformed to conform the requirements of subsequent finishing.

Research on Kinematics Analysis Method and Its Application of Circular Developable Mechanisms

HAN Ying-Ying, YUAN Ru, ZHENG Yu-Qi

2013, 24(09):  1142-1145. 

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Combining with Moore_Penrose generalized inverse theory and the motion transfer matrix of spatial linkage, the kinematics analysis method of multi developable linkage mechanisms was established herein. Using the method advanced by Gan and Pellegrino, the constraint equations of motion of the mechanisms and the Jacobian matrix of constraint equations were obtained. According to the singular and rank deficient characteristics of the Jacobi matrix, the least squares solution of motion parameters of the mechanisms was given. Taking the deployable mechanisms of four-bars for example, the influence law of the section angle of bar on angles of folding and spreading was obtained and the curve of the angle among bars during the movement of spreading was got, which lays the foundation for the motion control.

Experimental Study of Free  Abrasive Wire Sawing Mechanism

WANG Jin-Sheng, TAO Chun-Yan, BANG Wei

2013, 24(09):  1146-1149. 

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VW-6000/5000 dynamic microscope system  was used to observe the motion state of the abrasive particles in the free abrasive wire sawing.The results show that the abrasive particles have two states in the cutting area,one is contact state,another is non-contact state.Optical glass(K9) was cut by 0.16mm  wire saw coated with resin and steel wire saw and sawing mechanism has been proved.The results show that slicing efficiency of the steel wire saw is much higher than that of wire saw coated with resin.Surface of the as-sawn optical glass by steel wire saw has many tiny pits but no scratch.Surface of the as-sawn wire saw coated with resin has many abrasive particles and surface of steel wire saw has many tiny pits.These results indicate that sawing mechanism is mainly rolling-indenting removal in the free abrasive wire sawing.

Experimental Investigation into Material Removal Mechanism of Nano-ZrO2 Dental Ceramic Grinding

HAN Zhen-Lu-1, LI Chang-He-1, WANG Qing-1, MAO Wei-Beng-2

2013, 24(09):  1150-1154. 

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Aiming at the theoretical analysis and experimental investigation on the critical conditions for the brittle-ductile removal mechanism in nano-ZrO2 dental ceramic grinding,a K-P36 numerical-control precision surface grinder was employed for the grinding test on 3Y-TZP nano-ZrO2 dental ceramics. The YDM-III99 integral three-dimensional piezoelectric grinding dynamometer was employed to measure three-dimensional grinding forces. The TALSURF5 contourgraph was used to measure the micro-geometrical parameters after the grinding, and a SEM was used to observe the variation in the surface micromorphology. The experimental results indicate that the maximal thickness of the undeformed chip thickness smaller than 1.9μm corresponds to the ductile removal mode. The brittle-fracture removal induced by side cracks appears when the maximal thickness of undeformed chip thickness is between 1.9 and 2.1μm, and the removal mode is brittle-ductile mixed removal. When the maximal thickness of undeformed chip thickness is as 5.23μm, large-scale brittle fracture appears at the grinding surface, and a large number of pits induced by the brittle fracture in half-coin shape remaines on the surface.

Application on Binocular Vision System of a Mobile Robot

WANG Dian-Jun

2013, 24(09):  1155-1158. 

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In order to use binocular vision for indoor mobile robot localization, a mobile robot localization system was developed, and the principles of binocular vision localization were analyzed. The experimental system was established with MicronTracker vision system and mobile robot. The distance experiment of binocular vision was given, and ranging precision was analyzed, then the worst deviation is as 8.644mm.On the basis of above work, mobile robot localization tests show that binocular vision localization worst deviation is as 3.635cm. The system has higher precision, stability and less affect by environment, which can meet the positioning requirements of mobile robot.

Control Strategy for Wide Speed Domain of AC Asynchronous Motor Used in Electric Vehicle

HU Jian-Jun, DAN Gao-Liang, QIN Da-Tong

2013, 24(09):  1159-1164. 

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During speed control of AC asynchronous motor, according to the problems of direct current offset caused by traditional voltage model flux observer, a corresponding low-pass filter equipped with a real-time adjusting cut-off frequency and saturated feedback was designed for flux observer. A flux weakening control method with constant voltage was made in order to solve the problem of inaccurate calculation for traditional weak magnetic, so steady speed control was implemented efficiently in both constant torque region and weak magnetic region. Based on rotor field-oriented, the mathematical model of AC asynchronous motor was established using vector control. On the basis of above, a speed control strategy with model reference adaptive system was developed considering comprehensively constant torque region and weak magnetic region. The simulation and experimental results show that using the proposed control strategy can obtain good control effects, the legitimacy and effectiveness of proposed algorithm is verified.

Design and Algorithm for Polyhedron Metro Frame of  Lithographic Machine

TUN Fei, WANG Qian, YUAN Zhi-Yang, WEI Wei, CHEN Wen-Shu

2013, 24(09):  1164-1168. 

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A metrology frame for scanner lithographic machine was created,which was required to set-up optical projector and various nanometer-level measurement sub-system. To meet the requirements with minimized occupied-3D space,position data were collected firstly.That means to define all the interfaces and assembly positions on both metrology frame and measurement frame. Convex hull algorithm of computational geometry was used to settle the metrology frame outside polyhedron profile.Due to the complexity of machine structure, a local modification was followed to improve the model. Furthermore, plate cutting polyhedron algorithm was introduced to design the metrology frame inner structure. Finally, with finite element analysis and verification, a clear improvement can be visualized for both high modal value and low weight material consuming. Design performance target was reached; structure was fit to engineering manufacture.

Safety Analysis of Large-scale Construction Machine

YANG Chao-Pu-1, GENG Hai-Jun-1, GUO Wen-Wu-1, WANG Jin-Xiang-2, CA Wei-Dong-3

2013, 24(09):  1169-1173. 

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Safety analysis of large-scale construction machine is very important to safety design and safety monitor. A three dimensional safety analysis system  was presented based on construction technology section, in which a large-scale construction machine was divided into subsystems and the construction technology into sections. Through the analyses of subsystems in each section, this system provides a systemized method for safety analysis of large-scale construction machine. Based on the presented  method, the safety analysis of 900tons bridge erector which was used in high-speed railway construction was made to instruct the safety design of this machine.

Research on Micro-magnetic Detecting Mechanism of Defect Based on Micro-magnetics Analysis

LIU Mei-Quan-1, SUN Qin-Lei-1, JIANG Zhong-Bao-2

2013, 24(09):  1173-1176. 

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The micro-magnetic fixed knot which did not depend on the outer magnetic field formed near the defects, because the domain wall in the ferro-magnets was pinned by the defects.  The singular distribution of magnetizing field in the micro-magnetic fixed knot near the defects was calculated by the method of minimum energy form micro-magnetics analysis. Defect detection can be realized according to the distribution characteristics and what proposed herein provides a theoretical basis for defect micro-magnetic defection.

Effect of Grinding Parameters on Internal ELID Grinding of Bearing Rings

LI Qin-Feng, LIN Cheng-Jie, ZHANG Kai-Fei

2013, 24(09):  1177-1180. 

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It was investigated that the influences of depth of cut and wheel feed rate on internal ELID grinding based on the vibration signals. With a series of experiments using different parameter combinations, the effects of depth of cut and wheel feed rate on ELID grinding were compared. The experimental results show that depth of cut has a greater influence than that of wheel feed rate. In actual process a big depth of cut can be firstly used to obtain a large material removal rate, then a small depth of cut can be used to obtain a good surface quality, and the amplitude of vibration in process can predict the waviness on workpiece surface.

Research on a Hardware-in-the-loop Simulation Platform of Engine Sensor- Fault

ZHOU Bing-1, YANG Jing-1, XI Gang-2, CHEN Feng-2

2013, 24(09):  1181-1185. 

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Considering the limitation of traditional development method of engine management system(EMS), a method to establish sensor-fault simulation system was proposed. Firstly, a hardware-in-the-loop simulation platform, which was used for EMS function test, was developed in the LabVIEW and VeriStand environment. Secondly, by using this platform, a sensor-fault simulation system was set up for throttle position, intake air pressure, and engine water temperature. Finally, the real vehicle test of throttle position sensor-fault, for example, verified the effectiveness of the developed fault-tolerant packet. Then comparison between simulation and real vehicle test shows that the system established by this method can satisfy the test requirements, and has the advantages of higher reliability, convenience and precision.

Research on Inter-organizational Resources Chain Construction Based on Improved PSA

WANG Zheng-Cheng, XIAN Da

2013, 24(09):  1186-1190,1194. 

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In view that temporal constraint task chain drived resource chain construction to solve problems on inter organizational resources sharing, a non-constraint mathematical model for inter-organizational resource chain construction was proposed, the mathematical model adopted penalty function and aimed to time,cost and service capacity comprehensive optimization. Then, an improved binary PSA for solving the model was designed. By introducing particle position coding,parameter setting and position updating which were time changing and self adapting, the improved algorithm can enhance convergence speed and global search capability. Through a simulation example, according to the improved binary PSA, an inter-organizational resources chain was realized which was based on time, cost and service capacity comprehensive optimization. The results of the study and comparative analysis show that the method is effective and feasible.

Surface Roughness Prediction of Electrochemical Machining and Orthogonal Optimization of Processing Parameters Based on Neural Networks

LONG Gui-Bing, LI Dian-Meng, ZHANG Li-Ping, DIAO Xiu-Jun, BANG Pan-Beng

2013, 24(09):  1191-1194. 

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It can be an important vehicle to investigate surface roughness of the parts caused by the electrochemical processing and working current, handling backlash, electrolyte temperature, machining time, electrolyte ratio etc. These relevant processing parameters presented a non-linear relationship according to the parts roughness characteristics. Due to this relevance mechanism was still unexplored in the current electrochemical machining method, this paper investigated the relationship of previous processing parameters and the roughness characteristics in a mathematics way. Accordingly, a mathematical model was set up for expected BPNN training study. Through the experimental  data acquisition and training operations, it shows that in this way a minor prediction error is produced. In this case, utilizing the orthogonal analysis method, the surface characteristics with large changement amplitude can be realized with the optimized processing parameters.

Ontology-based Diagnostic Bayesian Networks for Mechanical Fault Diagnosis

QIN Da-Li-1, 2, XU De-Ge-1

2013, 24(09):  1195-1200,1209. 

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In view of the uncertainty of mechanical plant maintenance and fault diagnosis process, a hybrid fault reasoning model, which combined ontology semantic representation and Bayesian networks, was proposed. By extracting multi-source heterogeneous diagnostic information and non-structured experts' knowledge, a diagnostic ontology was constructed with probabilistic extension. Abnormal working conditions were identified using Bayesian classifier, and a fault probabilistic inference algorithm based on MPE(most probable explanation) was given, consequently diagnostic explanations could be obtained by the algorithm in accordance with operating conditions, symptoms and evidences. Combining the accuracy of semantic description and the probabilistic inference ability of Bayesian networks, this model realizes formalism and sharing of diagnostic domain knowledge, and eliminates uncertainty within the diagnostic processes to some extents. A typical rotor's fault diagnosis instances in cooling tower fan demonstrates that the proposed model has preferable fault recognition results.

Dynamics Model of Helmet Mounted Display with a 6-DOF Parallel Manipulator and Corresponding Verification

LI Feng, GU Hong-Bin, TUN Dong-Su

2013, 24(09):  1201-1209. 

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Firstly,kinematic analysis for a manipulator of helmet mounted display with 6-DOF parallel manipulator was developed, and the kinematic relationship among lead screw, nut and platform was derived. Secondly, dynamics analysis of leg was carried out using Newton-Euler method, and the Newton-Euler equations of whole leg and corresponding parts including nut were built respectively considering friction at helix joint, and then a closed-form dynamics equation of 6URHS parallel manipulator was established. Finally, prototype, dynamics models of 6URHS were built respectively by Simulink, and some comparison tests about dynamic response were developed.The results of comparison tests show that the veracity of the dynamics models of 6URHS is as the same as the prototype. Additionally, trajectory tracking simulation was also implemented, and computation and analysis of driving torque were developed.

Cylinder IMEP Estimation Model Based on Flywheel Speed and Speed Variation

JUAN Long-Shen, HUI Xiao-Gang, TENG Xiao-Lei

2013, 24(09):  1210-1214. 

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The correlation among IMEP of each cylinder and product of flywheel mean angular velocity and angular velocity variation was analyzed in four cylinder gasoline engine，and their linear correlation was weak. The single operating condition model estimating IMEP of each cylinder through flywheel mean angular velocity and angular velocity variation was obtained by least square parametric recognition method. The steady-state condition model estimating IMEP of each cylinder was obtained by substituting polynomial of mean angular velocity, angular velocity variation and mean load for model index in single operating condition model. The error between estimated IMEP values and measured ones is below 8 percent.

Research on Machining Mechanism of Difficult-to-conductive Hard and Brittle Materials with Mist-jetting Electrochemical Discharge

XU Jian-Yuan, LIU Zhi-Dong, QIU Meng-Bei, WANG Lin, TIAN Zong-Jun

2013, 24(09):  1214-1219. 

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Three kinds of difficult-to-conductive hard and brittle materials such as single crystal silicon, optical glass and Al2O3 ceramic were researched with mist-jetting electrochemical discharge method, the machining principle was expounded, and the heat transfer physical model was constructed. Machining discharge waveforms and surface microstructures were analyzed to get the erosion methods of difficult-to-conductive hard and brittle materials. The research results show that, the erosion methods are electrochemical corrosion, electrochemical discharge and chemical dissolution for semiconductor such as silicon; local high temperature generated by electrochemical discharge makes soften layer and chemical dissolution reactes for the insulating materials which is easy to soften such as optical glass; and for the insulating materials with high melting-point, electrochemical discharge can only make soften layer which then removed by mechanical way through ductile regime method.

Study on Control Policy of Over-bending Setting Round for Pipe Ends of Large Pipes

ZHAN Pei-Pei, DIAO Jun, CHANG Jing-Hua, MA Rui

2013, 24(09):  1220-1224. 

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Over-bending setting round for pipe end is one of the most important processes to make the large pipes standard. The study of rigidity influence in the forming process and the logical control policy are the base to formulate the proper technological parameter. Through the physical test, this paper contrasted the mould press type bending process of long pipe billet end and the mould press type bending process short pipe billet, and established the relationship between the pipe ovality and the deformation, thereby a control policy of mould press type over-bending setting round for large pipe end was built.The experimental results suggest that the control policy can control the residual ovality of pipe-end within 0.5%.

#br# Experimental Study of Semi-fixed Wire Sawing

BANG Wei, WANG Jin-Sheng, TAO Chun-Yan

2013, 24(09):  1225-1228,1232. 

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In view of low sawing efficiency and large kerf loss in the free abrasive wire sawing, a new method of semi-fixed wire sawing was put forward. In order to improve sawing efficiency and reduce kerf loss, wire saw surface made groove and abrasive particles were embedded into the groove to realize the instant consolidation. VW-6000/5000 dynamic microscope system observed the motion state of the abrasive particle in the cutting area. The results indicate that abrasive particle can realize the instant consolidation in the groove. The differences in sawing efficiency, surface roughness and kerf width by semi-fixed wire saw and steel wire saw were analysed by cutting experiments.

Study on Infrared Image Denoising of Friction Pairs Based on Morphological Edge Detection and Wavelet Threshold

SHU Jian-Wei-1, 2, LUO Zhen-Shan-1, YIN Yan-Guo-1, 2, YOU Chao-1

2013, 24(09):  1229-1232. 

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The common method of wavelet threshold denoising for infrared image processing usually distorts the edge in image. A new method, combining the mathematical morphology edge detection and the wavelet threshold denoising, was presented and applied in denoising the infrared image of friction surface. Infrared image was processed through three steps: wavelet transformation, mathematical morphology edge detection in the high-frequency sub-band for determination the location of edge and threshold denoising. Experimental results show that this method can preserve more edge information, improve mean square deviation and peak signal-to-noise ratio. The intention of this approach is to improve the accuracy of the temperature measurement of the infrared images, thus it provides better technical support for measuring and analyzing friction temperature field with the high engineering values.

Comparative Study on Rolling Riveting and Pressing Riveting

HUANG Zhi-Chao, LIU Xiao-Kun, TIE Jin-Jing

2013, 24(09):  1233-1238. 

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The finite element simulations of the rolling riveting and the pressing riveting for connecting the aluminum alloy sheets were carried out using the finite element software DEFORM. The stress-strain curve and force-displacement curve of the rolling riveting and pressing riveting were compared. The tensile tests of the lap joints for the two kinds of joining technology were performed. The results show that the loads for the rolling riveting are much lower than those for the traditional pressing riveting to achieve the same forming effect. The ability of tear and peeling for the rolling riveting joint is better than those for the pressing riveting, but the shear capacity of the rolling riveting joint is poorer.

Parameter Optimization for a Novel Mechanical Leg

LI Xing-Biao, LIU Yi, LI Jing-Min, JI Shi-Ming, DIAO Zhang-Feng

2013, 24(09):  1239-1245. 

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Parameter optimization for a novel mechanical leg was presented by using statistics method called statistics parameter optimization method based on index atlases. Several kinematics and mechanics performance evaluation indices were proposed and discussed according to the kinematics and mechanics analysis of the mechanical leg. Considering the assembly technique, a design scheme of the mechanical leg was developed using the statistics parameter optimization method based on the index atlases, which provided the basis for the applications of the mechanical leg. The novel mechanical leg can be applied in the modern humanoid robot fields which require high stiffness, lower inertia and good technological efficiency etc.

Pole Assignment of Multi-steering Vehicle Based on State Feedback with Full-order Observer

WANG Ji-Hua-1, 2, WEI Min-Xiang-1, DU Yan-Li-1, 2, LI Yu-Fang-1

2013, 24(09):  1246-1251,1257. 

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A method for improving performance of a multi-steering vehicle was proposed by reconstructing states with observer and the poles were assigned by using reconstructed states. The multi-steering vehicle with two degree of freedom (2DOF) was modeled. Full-order observer was designed to reconstruct lateral angle based on input of system and yaw rate that was measured easily, and state feedback controller was designed to assign poles based on the reconstructed states and the expected poles of system. Through simulation, observer tracks states of the vehicle accurately and steerage response is rapid and smooth, and the control system is robust at the range of ±5° of rear angle，and control effect is much better than that of PID control. The results indicate that the designed controller by using the method can improve the dynamic performance and handling stability of multi-steering vehicle effectively.

Optimization of Underhood Temperature Field for a Passage Car

LIU Guo-Qiang-1, 2, YANG Mo-Li-2, DENG Xiao-Long-2

2013, 24(09):  1252-1257. 

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During underhood temperature field experimental development for some passage cars, surface temperature of drive shaft oil seal and battery is in excess of the limit. To find the reason, detailed CFD model of underhood for air flow and heat transfer analysis was established. The temperature boundary conditions for main heat resources were obtained by experiments, and the radiation heat transfer was also considered. The air flow distribution and temperature field in underhood under test conditions were solved. Simulation results indicate that, over high temperature of drive shaft oil seal is because of that oil seal is very close to hot resource while the air flow velocity around it is small, for battery it is owing to flow circumfluence through radiator and fan which causes that air blowing to the battery surface is repeating heated. Based on this, structure to guide cool air and heat insulation were added near drive shaft oil seal and battery, and their shapes were optimized by CFD simulation, and the final effect was validated by experiments.It is shown that measured temperature of oil seal and battery reduces significantly, the underhood temperature overhigh issues are then eliminated.

Research on Vehicle Driving Situation Identification(Part Ⅰ)——Driving Pattern Selection

TIAN Yi-1, 2, 3, ZHANG Xin-2, ZHANG Cuan-2, ZHANG Liang-2

2013, 24(09):  1258-1263. 

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A hybrid search algorithm was built herein, which combined effectively the genetic algorithm and the floating search algorithm. This hybrid search algorithm firstly searched the boundary among driving pattern parameters through adaptive genetic algorithm and got the universal set of vehicle driving patterns; then the best subset was selected by using the floating search algorithm. In the hybrid search algorithm, the start point of floating selection algorithm was the best, which was chosen from each cycle of genetic algorithm calculation. So most of the invalid searches can be avoided and the searching time decreased, too. A best driving pattern subset is obtained which includes eight parameters.

Advances in Probes of Micro-nano Coordinating Measuring Machine

HUANG Jiang-Xian, TU Hui-Juan, HUANG Shuai, JIAN Jian-Zhao

2013, 24(09):  1264-1272. 

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Probes are the key components of micro-nano CMM.According to the development perspective of micro-nano 3-dimensional measurement and its present research situation, the new requirements of the probes including contact probes, non-contact probes and probes developed with new technology, were described herein firstly. Then, the domestic and foreign research progresses of micro-nano CMM probes were reviewed and compared, and the main problems of two kinds of probes needed to be solved were listed. In order to overcome the shortages of these probes, a new developing three-dimensional resonant trigger probe was discussed. Finally, the summary and prospect of the micro-nano CMM probes research and development were given.

Progresses of Nano Welding Technology Based on Nanojoining

CHEN Ji-Min

2013, 24(09):  1273-1277. 

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The nanojoing or nanowelding technology is necessary to create the nano devices in nanofabrication. Many scientists of the world  performed research toward  joining nanowires to form nano function devices. Current nano welding technologies were introduced herein,including heat input of fusion welding and cold welding without heating. The direct current electric and light were used as heating source in fusion welding. The spontaneous welding of nanowire contact can be also finished without heat. The weldable materials were metallic nanowire such as gold, silver as well as non metallic carbon nano tubes(CNTs).