Investigation of Friction Stir Spot Welding Optimal Parameter Combination for Galvanized Trip Steel

2016 ◽  
Author(s):  
R. M. Chandima Ratnayake ◽  
Magomed M. Suleymanov ◽  
Lars E. M. Skedsmo ◽  
Vegard Goa
Keyword(s):  
Trip Steel ◽  
Spot Welding ◽  
Optimal Parameter ◽  
Load Capacity ◽  
Additive Model ◽  
Tensile Load ◽  
Friction Stir Spot Welding ◽  
Lap Joints ◽  
Friction Stir ◽  
Influence Parameter

Friction stir spot welding (FSSW) is performed on transformation-induced plasticity (TRIP) steel (HCT690T) sheets. The influence of parameters: rotational speed, dwell time plunge depth and plunge speed on a mechanical property of lap joints are investigated. An engineering robust design (ERD) approach has been utilized to design the experiment with L9 orthogonal array. In order to minimize the bias, each experiment has been repeated three times, resulting in 27 experiments. For each influence parameter, three levels have been identified (i.e. minimum, average and maximum) based on trial and error experimentation as well as utilizing published research data. The ultimate tensile load capacity (UTLC) of TRIP lap welded joints has been used to assess the joint performance and to calculate the signal-to-noise ratios. Based on the experimental results, optimal parameter levels have been investigated and theoretical joint strength under the optimal parameter settings has been calculated using the additive model proposed in the ERD. A verification experiment has been performed to validate the experimentally investigated optimal settings of FSSW.

Simulative Model for the Evaluation of Thermo-Mechanical Effects in Friction Stir Spot Welding (FSSW) of Aluminum Sheets

2014 ◽  
Vol 622-623 ◽  
pp. 557-566
Author(s):  
G. D’Urso ◽  
Claudio Giardini
Keyword(s):  
Process Parameters ◽  
Spot Welding ◽  
Welding Process ◽  
Friction Stir Spot Welding ◽  
Lap Joints ◽  
Local Pressure ◽  
Friction Stir ◽  
Welding Forces ◽  
Set Up ◽  
Simulative Model

A study was performed to evaluate how the Friction Stir Spot Welding process parameters affect both the thermal distribution in the welding region and the welding forces. An experimental campaign was performed by means of a CNC machine tool and FSSW lap joints on AA6060-T6 aluminum alloy plates having a thickness of 2+2 mm were executed. Five thermocouples were inserted into the samples at a specific distance from the specimen center. A set of tests was carried out by varying the process parameters, namely rotational speed, axial feed rate, plunging depth and dwell time. Axial welding forces were also measured during the execution of the experiments by means of a piezoelectric load cell. The experimental data collected were used to set up and to validate a simulative model of the process. In particular, a 2D FEM model was set up using the commercial code Deform 2D. A 2-dimensional FEM code was preferred in order to guarantee a very simple and practical model able to achieve results in a very short time. Since it is not possible to simulate the rotation of the tool in a 2D configuration, a specific external routine for the calculation of the developed thermal energy due to the friction between tool and workpiece was set up and implemented into the code starting from the local pressure distribution along the contact area.

Towards Tool Path Numerical Simulation in Modified Friction Stir Spot Welding Processes

2009 ◽  
Vol 83-86 ◽  
pp. 1220-1227
Author(s):  
Gianluca Buffa ◽  
Livan Fratini
Keyword(s):  
Spot Welding ◽  
Tool Path ◽  
Base Material ◽  
Welding Process ◽  
Friction Stir Spot Welding ◽  
Lap Joints ◽  
Hollomon Parameter ◽  
Friction Stir ◽  
Strain And Strain Rate ◽  
Welding Processes

Spot welding can be considered a very common joining technique in automotive and transportation industries as it permits to obtain effective lap-joints with short process times and what is more it is easily developed through robots and automated systems. Recently the Friction Stir Spot Welding (FSSW) process has been proposed as a natural evolution of the already known Friction Stir Welding (FSW) process, allowing to obtain sound spot joints that do not suffer from the insurgence of typical welding defects due to the fusion of the base material. In the paper, a modified Friction Stir Spot Welding (FSSW) process, with a spiral circular movement given to the tool after the sinking stage, is proposed. A continuum based numerical model for Friction Stir Spot Welding process is developed, that is 2D Lagrangian implicit, coupled, rigid-viscoplastic. This model is used to investigate the distribution of the main field variables, namely temperature, strain and strain rate, as well as the Zener-Hollomon parameter which, in turn, strongly affects the Continuous Dynamic Recrystallization (CDRX) process that takes place in the weld nugget. Numerical and experimental results are presented showing the effects of the process parameters on the joint performances and the mechanical effectiveness of the modified process.

scholarly journals Mechanical Properties of Dissimilar A356/SAPH440 Lap Joints by the Friction Stir Spot Welding and Self-Piercing Riveting

2018 ◽  
Vol 50 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Han Sur Bang ◽  
W. R. Lee ◽  
S. M. Hong ◽  
S. Y. Lee ◽  
J. H. Song ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spot Welding ◽  
Friction Stir Spot Welding ◽  
Lap Joints ◽  
Friction Stir

Microstructural and Mechanical Observations of Galvanized TRIP Steel after Friction Stir Spot Welding

2015 ◽  
Vol 30 (9) ◽  
pp. 1090-1103 ◽  
Author(s):  
C. C. P. Mazzaferro ◽  
T. S. Rosendo ◽  
M. A. D. Tier ◽  
J. A. E. Mazzaferro ◽  
J. F. Dos Santos ◽  
...  
Keyword(s):  
Trip Steel ◽  
Spot Welding ◽  
Friction Stir Spot Welding ◽  
Friction Stir

scholarly journals Correction to: Mechanical Properties of Dissimilar A356/SAPH440 Lap Joints by the Friction Stir Spot Welding and Self-Piercing Riveting

2018 ◽  
Vol 50 (3) ◽  
pp. 515-515
Author(s):  
HeeSeon Bang ◽  
W. R. Lee ◽  
Seong Min Hong ◽  
S. Y. Lee ◽  
J. H. Song ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spot Welding ◽  
Friction Stir Spot Welding ◽  
Lap Joints ◽  
Friction Stir

scholarly journals Simultaneous Effect of Tool Rotation and Dwell Time on Quality of Dissimilar AA5052-Copper Joints Fabricated by Friction Stir Spot Welding

2021 ◽  
Author(s):  
Aydin Jadidi ◽  
Reza Bagherian Azhiri ◽  
Amir Baghdadchi ◽  
Abolfazl Salmani Bideskan
Keyword(s):  
Shear Strength ◽  
Spot Welding ◽  
Dwell Time ◽  
Quality Characteristics ◽  
Friction Stir Spot Welding ◽  
Lap Joints ◽  
Lap Shear Strength ◽  
Friction Stir ◽  
Lap Shear ◽  
Rotary Speed

Abstract In the present study, lap joints of dissimilar 5052 aluminum alloy and pure copper were fabricated by friction stir spot welding process. The work was aimed to find effect of parameters such as tool rotary speed (1000, 1400 and 2000 RPM) and dwell time (5, 10 and 15s) on microstructure and strength properties of lap joints. Also, statistical models of the quality characteristics were developed to understand which interaction has dominant effect on quality characteristics. Research findings showed that to obtain sound joints with high lap shear strength tool rotary speed of 2000 rpm and dwell time of 5s should be selected. It provides sufficient heat input and prevents the excessive material softening. On the other hand, to achieve maximum hardness, 2000 rpm tool rotary speed should be chosen to provide enough heat for formation of intermetallic compound and 10s dwell time should be used prevent enough time for microstructure refining. Moreover, from the statistical analyses, it was found that dwell time and tool speed are the significant factor for lap shear strength and hardness, respectively. In order to attain simultaneous maximum strength and hardness, tool speed of 2000 rpm and dwell time of 8 s should be used. In such condition lap shear strength of 1755 N and hardness of 77 V are achieved with desirability of 85%.

Investigating Optimal Parameter Combination for Friction Stir Spot Welding on AL7075-T6: Engineering Robust Design Approach

2021 ◽  
Author(s):  
Jan-Tore Jakobsen ◽  
R. M. Chandima Ratnayake ◽  
Sølve Sætre Sem ◽  
Arnfinn Neverdal
Keyword(s):  
Robust Design ◽  
Spot Welding ◽  
Dwell Time ◽  
Failure Load ◽  
Optimal Parameter ◽  
Friction Stir Spot Welding ◽  
Design Approach ◽  
Friction Stir ◽  
Optimum Parameters ◽  
Ultimate Failure

Abstract Friction stir spot welding (FSSW) is a solid-state joining technique which is used to weld alloys that has a low weldability such as the 2000 and 7000 series aluminum alloy. The marine, automotive and aerospace industry benefits using this method as the need for weight reduction and fuel economy make the use of aluminum and other light metals necessary. The purpose of this study is to find the optimum parameters and the ultimate failure load for FSSW welded specimens in a basic lap configuration. Two coupons of AA7075-T6 with a dimension of 210 × 30 × 0.8 mm and 210 × 30 × 1.6 mm were welded using a self-made FSSW machine rebuild for the purpose of this project. The experiment was performed using engineering robust design approach to investigate the optimal parameter combinations that provides optimal joint performance. Experiments has been carried out using the Taguchi L9 orthogonal arrays with 4 factors and 3 levels. The factors and levels were chosen as follows: pin length in the interwall 1.2 mm to 1.6 mm, shoulder depth 0 to 0.4 mm, dwell time 1 sec to 2.5 sec and tool rotation speed 1800 rpm to 2600 rpm. The joint performance has been evaluated considering the ultimate tensile load. Tensile testing of weldments was carried out using an Instron Universal Testing Machine. To estimate the error variance for the factor effects and variance of the predicted error analysis of variance (ANOVA) was performed. The mathematical framework anticipated an ultimate failure load of 3286N, and the verification run confirmed the predicted result by an average of 3215N. The optimum parameters were found to be a pin length of 1.4 mm, shoulder depth of 0.4 mm, dwell time at 2.5 sec and a rotational speed of 2200 RPM. The ANOVA showed that the shoulder depth was the dominant factor influencing 87.9 % of the variation of the signal-to-noise ratio (S/N).

scholarly journals A Weighting Grade-Based Optimization Method for Determining Refill Friction Stir Spot Welding Process Parameters

2019 ◽  
Vol 28 (10) ◽  
pp. 6471-6482
Author(s):  
Rafał Kluz ◽  
Andrzej Kubit ◽  
Tomasz Trzepiecinski ◽  
Koen Faes ◽  
Wojciech Bochnowski
Keyword(s):  
Process Parameters ◽  
Rotational Speed ◽  
Spot Welding ◽  
Load Capacity ◽  
Base Material ◽  
Welding Process ◽  
Friction Stir Spot Welding ◽  
Welding Parameters ◽  
Tool Rotational Speed ◽  
Friction Stir

Abstract The welding process used in fabricating thin-walled structures by refill friction stir spot welding (RFSSW) should be characterized by a high strength of welds and high process repeatability which is demonstrated by a small dispersion of the load capacity of the joints. The present work is designed to optimize RFSSW process parameters for 7075-T6 Alclad aluminum alloy sheets used to fabricate aircraft structures. The optimization was performed by scalarization of the objective function using the weighting grades method. The study considers the effect of process parameters, i.e., tool plunge depth, duration of welding, tool rotational speed, on the tensile/shear strength of the joints, and dispersion of the load capacity. It was found that it was possible to choose the optimal welding parameters taking into account maximization of the load capacity and minimization of the dispersion of the joint strength via a best compromise between the tool rotational speed ensuring adequate plasticization of the base material and the duration of welding ensuring that a fine-grained joint microstructure is obtained.

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