scholarly journals Nugget Diameter in Resistance Spot Welding: A Comparison between a Dynamic Resistance Based Approach and Ultrasound C-scan

2017 ◽  
Vol 183 ◽  
pp. 257-263 ◽  
Author(s):  
Cameron Summerville ◽  
David Adams ◽  
Paul Compston ◽  
Matthew Doolan
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Dynamic Resistance ◽  
Resistance Spot ◽  
Nugget Diameter

Dynamic Electrode Force and Displacement in Resistance Spot Welding of Aluminum

2004 ◽  
Vol 126 (3) ◽  
pp. 605-610 ◽  
Author(s):  
C. T. Ji, ◽  
Y. Zhou,
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Current ◽  
Monitoring And Control ◽  
Resistance Spot ◽  
Nugget Diameter ◽  
Electrode Force ◽  
Rate Of Increase ◽  
Process Monitoring And Control ◽  
Electrode Displacement

Dynamic electrode displacement and force were characterized during resistance spot welding of aluminum alloy 5182 sheets using a medium-frequency direct-current welder. It was found that both electrode displacement and force increased rapidly at the beginning of the welding stage and then at a reducing rate. Rates of increase in electrode displacement and force were both proportional to welding current. And both electrode displacement and force experienced a sudden drop when weld metal expulsion occurred. However, the rate of increase in electrode displacement did not reach zero during welding even for joints with sufficient nugget diameter, while electrode force peaked when a large nugget diameter was produced. Possible strategies for process monitoring and control were also discussed.

scholarly journals STUDI LITERATUR PENGARUH PARAMETER PENGELASAN TERHADAP SIFAT FISIK DAN MEKANIK PADA LAS TITIK (RESISTANCE SPOT WELDING)

ROTASI ◽  
2013 ◽  
Vol 15 (2) ◽  
pp. 44
Author(s):  
Haikal Haikal ◽  
Triyono Triyono
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Electric Current ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Dissimilar Materials ◽  
Dissimilar Metals ◽  
Welding Time ◽  
Resistance Spot ◽  
Nugget Diameter

Resistance spot welding (RSW) is the most widely used for joining thin sheet metals in automotive industry. Various applications of dissimilar materials and thicknesses were commonly found in many spot welding processes especially in the manufacture of car body. The resistance spot welding of dissimilar materials are generally more challenge than similar materials due to differences in the physical, chemical, and mechanical properties of the base metals. Differences of materials have an impact on heat input generated at the spot welding. Diameter of the weld nugget size is influenced by several parameters such as electric current, welding time, different types of material, and the thickness of the plate. Nugget diameter will influence on physical and mechanical properties weld such as microstructure, shear strength and hardness. For practical use, various industrial standards have recommended a minimum weld size for a given sheet thickness, mostly in the form of tables. For example the American Welding Society (AWS), Society of Automotive Engineering (SAE) and the American National Standards Institute (ANSI). They were only suitable to be apllied on the similar metal and thickness joint because in this joint, symetrical nugget will be formed. Meanwhile a type of dissimilar metal that joined by spot welding method will result in the asymetrical nugget. This paper aims to review the results of researchs on the similar and dissimilar resistance spot welded joint to evaluate the use of similar metals weld parameters and standards on the dissimilar metals weld. It was determined that parameters welding such as electric current, welding time, and the standard for similar metals weld can not be applied on the dissimilar metals weld. The asymetrical nugget shape decreased shear strength on the weld nugget. The most important factor that was considered on the dissimilar metals weld to make high quality weld joint was nugget diameter. If the nugget diameter weld increased the strength of welding will increase.

A new measurement method for the dynamic resistance signal during the resistance spot welding process

2016 ◽  
Vol 27 (9) ◽  
pp. 095009 ◽  
Author(s):  
Lijing Wang ◽  
Yanyan Hou ◽  
Hongjie Zhang ◽  
Jian Zhao ◽  
Tao Xi ◽  
...  
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Measurement Method ◽  
Welding Process ◽  
Dynamic Resistance ◽  
Resistance Spot

Modeling Dynamic Electrical Resistance During Resistance Spot Welding

2000 ◽  
Vol 123 (3) ◽  
pp. 576-585 ◽  
Author(s):  
S. C. Wang ◽  
P. S. Wei
Keyword(s):  
Electrical Resistance ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Transport Processes ◽  
Dynamic Resistance ◽  
Resistance Curve ◽  
Bulk Resistance ◽  
Resistance Spot ◽  
Faying Surface ◽  
Stage 4

Dynamic electrical resistance during resistance spot welding has been quantitatively modeled and analyzed in this work. A determination of dynamic resistance is necessary for predicting the transport processes and monitoring the weld quality during resistance spot welding. In this study, dynamic resistance is obtained by taking the sum of temperature-dependent bulk resistance of the workpieces and contact resistances at the faying surface and electrode-workpiece interface within an effective area corresponding to the electrode tip where welding current primarily flows. A contact resistance is composed of constriction and film resistances, which are functions of hardness, temperature, electrode force, and surface conditions. The temperature is determined from the previous study in predicting unsteady, axisymmetric mass, momentum, heat, species transport, and magnetic field intensity with a mushy-zone phase change in workpieces, and temperature and magnetic fields in the electrodes of different geometries. The predicted nugget thickness and dynamic resistance versus time show quite good agreement with available experimental data. Excluding expulsion, the dynamic resistance curve can be divided into four stages. A rapid decrease of dynamic resistance in stage 1 is attributed to decreases in contact resistances at the faying surface and electrode-workpiece interface. In stage 2, the increase in dynamic resistance results from the primary increase of bulk resistance in the workpieces and an increase of the sum of contact resistances at the faying surface and electrode-workpiece interface. Dynamic resistance in stage 3 decreases, because increasing rate of bulk resistance in the workpieces and contact resistances decrease. In stage 4 the decrease of dynamic resistance is mainly due to the formation of the molten nugget at the faying surface. The molten nugget is found to occur in stage 4 rather than stage 2 or 3 as qualitatively proposed in the literature. The effects of different parameters on the dynamic resistance curve are also presented.

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