Simulation of capacitor discharge stud welding process and void formation

2007 ◽  
Vol 12 (3) ◽  
pp. 274-281 ◽  
Author(s):  
H. S. Oh ◽  
J. H. Lee ◽  
C. D. Yoo
Keyword(s):  
Void Formation ◽  
Welding Process ◽  
Capacitor Discharge ◽  
Stud Welding

Effect of the welding process on microstructure, microhardness and residual stresses of capacitor discharge stud welded joint

2021 ◽  
pp. 1-23
Author(s):  
Qian Zhang ◽  
Bao-Zhu Zhang ◽  
Yun Luo ◽  
Gang Yang ◽  
Hong-xiang Zheng
Keyword(s):  
Residual Stresses ◽  
Weld Joint ◽  
Weld Seam ◽  
Welded Joint ◽  
Weld Zone ◽  
Welding Process ◽  
Capacitor Discharge ◽  
Stud Welding ◽  
Carbon Plate ◽  
Extension Length

Abstract Capacitor discharge (CD) stud welding is a common and fast connection technology. This paper presents an experimental and simulation study of the stud weld joint of copper stud and carbon plate. An optimized stud welding process was proposed based on microstructure, microhardness and residual stresses of CD stud welded joint. The results show that a narrow weld seam with widmanstaten structure were formed because of quickly cooling. For the longer stud extension length, the width of weld zone becomes wider and the microstructure becomes more uniform. As the increase of welding voltage and stud extension length, the microhardness increases then decreases. However, the residual stresses are increased with welding voltage increases, while they are decreased with the increases of stud extension length. The optimized welding voltage and stud extension length should be designed to 90 V and 5 mm, respectively. This study will provide a great significance to the stud welding on site.

Evolution of Interfacial Microstructure During Resistance Spot Welding of Cu and Al With Ni-P Coating

2021 ◽  
Author(s):  
Nannan Chen ◽  
Hongliang Wang ◽  
Jingjing Li ◽  
Vic Liu ◽  
James Schroth
Keyword(s):  
Heat Input ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Void Formation ◽  
Welding Process ◽  
Kirkendall Effect ◽  
Interfacial Microstructure ◽  
Formation Mechanisms ◽  
Elemental Distribution ◽  
Resistance Spot

Abstract Dissimilar materials of copper (Cu) to aluminum (Al) with nickel-phosphorus (Ni-P) coatings were joined using resistance spot welding. The Ni-P coatings were electroless plated on the Al surfaces to eliminate the formation of brittle Cu-Al intermetallic compounds (IMCs) at the faying interface between Cu and Al. Three welding schedules with various heat input were employed to produce different interfacial microstructure. The evolution of interfaces in terms of phase constitution, elemental distribution and defects (gaps and voids) was characterized and the formation mechanisms were elucidated. During the welding process, the bonding between Cu and Ni-P forms through solid-state diffusion, while the faster diffusion rate of Cu relative to Ni and P atoms promotes the generation of sub-micron voids. As the heat input increases, gaps at the Cu/Ni-P interface diminish accompanied by increase of sub-micron voids. A moderate schedule helps to remove the gaps and inhibits the void formation. An Al3Ni layer and nanovoids were found around the interface of Ni-P/Al. The increased heat input decreases the grain size of Al3Ni at the interface by eutectic remelting and increases the nanovoids by enhanced nanoscale Kirkendall effect.

Parameter Optimization and System Design of the Welding Power Supply for Resistance-Butt Welding of Nuclear Fuel Rod

2011 ◽  
Vol 201-203 ◽  
pp. 2661-2666
Author(s):  
Fang Quan Chen ◽  
Zu Wei Lin ◽  
Guo Wei Liang
Keyword(s):  
Nuclear Fuel ◽  
Power Supply ◽  
Welding Process ◽  
Capacitor Discharge ◽  
Butt Welding ◽  
Fuel Rod ◽  
Current Curve ◽  
Bridge Rectifier ◽  
And Control ◽  
Welding Power Supply

This paper firstly gives a brief description about the principle of resistance-butt welding of nuclear fuel rod, and it points out that the power supply is a key technology for welding process. According to the welding process and the welded material properties, capacitor discharge power supply is devised as welding power supply. The design of charging circuit of single-phase bridge rectifier with SCR and control circuit is finished. The process of power discharge is simulated and the parameters (capacitance C, charging voltage uc) are optimized with Matlab. By the welding experiments, it shows that the output current curve is suitable for resistance-butt welding of nuclear fuel rods, and the test results of welding samples entirely consistent with process requirements.

Capacitor Discharge Weld Modelling Using Ultra High Speed Photography

1993 ◽  
Vol 314 ◽  
Author(s):  
R. D. Wilson ◽  
J. A. Hawk ◽  
J. H. Devletian
Keyword(s):  
High Speed ◽  
Welding Process ◽  
Travel Speed ◽  
Analytical Models ◽  
High Speed Photography ◽  
Welding Time ◽  
Capacitor Discharge ◽  
Ultra High Speed ◽  
High Cooling Rates ◽  
Weld Area

AbstractCapacitor discharge welding (CDW) is a rapid solidification joining process where high cooling rates (106 K/s) are obtained as a result of the large weld surface area to small weld volume. The objective of this study, directed by the U.S. Bureau of Mines and the Oregon Graduate Institute of Science and Technology, was to use ultra-high speed photography to quantify transient arc behavior during the CDW cycle. The simple cylindrical geometries of the CD welds have been used to formulate analytical models which are compared to the high speed photographs of the welding process. The high speed photographs were analyzed with respect to welding time and process weld variables and compared to predicted values from the analytical model. The detailed photographic analyses revealed that material is continuously ejected as a plasma from the weld area due to induced magnetic forces, rather than having the liquid metal squeezed out of the weld upon contact. It was found that welding time was controlled by tip length and drop height. Results from high speed photographs found the arc travel speed around tube welds to be 109m/s. Finally, the high speed photographs revealed that the velocity of arc propagation during ignition was fast enough to allow the CDW process to be modelled as onedimensional heat flow.

Effects of welding flux on welding quality during arc stud welding process

2021 ◽  
pp. 1-12
Author(s):  
Deku Zhang ◽  
Xusheng Qian ◽  
Xiaopeng Li ◽  
Siyuan He ◽  
Kehong Wang
Keyword(s):  
Welding Process ◽  
Welding Quality ◽  
Welding Flux ◽  
Stud Welding

scholarly journals Optimization of friction stud welding process parameters by integrated Grey-Fuzzy logic approach

2018 ◽  
Vol 16 (4) ◽  
Author(s):  
N. Rajesh Jesudoss Hynes ◽  
R. Kumar ◽  
P. Shenbaga Velu ◽  
J. Angela Jennifa Sujana
Keyword(s):  
Fuzzy Logic ◽  
Process Parameters ◽  
Welding Process ◽  
Fuzzy Reasoning ◽  
Optimal Level ◽  
Metal Loss ◽  
Stud Welding ◽  
Fuzzy Logic Approach ◽  
Friction Stud Welding ◽  
Fuzzy Logic Technique

In this work, an integrated grey fuzzy logic technique is employed for solving the multi objective function of friction stud welding machine process parameters. This technique converts the multi-objectives into a grey fuzzy reasoning grade. According to the grey fuzzy reasoning grade, an optimal combination of process parameters is concluded. Here, Taguchi L9 orthogonal array is used to design the experiments. The objective of this work is to maximize impact strength and minimize metal loss during the joining of AA 6063 and AISI 1030 steel. Rotational speed, friction time, and friction pressure are considered as the input process parameters. The outcomes of the confirmation test show that good joining strength is accomplished by the optimal level of process parameters.

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