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Ferreira Magalhães, A. C., Cederqvist, L., De Backer, J., Håkansson, E., Ossiansson, B. & Bolmsjö, G. (2019). A Friction Stir Welding case study using Temperature Controlled Robotics with a HPDC Cylinder Block and dissimilar materials joining. Journal of Manufacturing Processes, 46, 177-184
Open this publication in new window or tab >>A Friction Stir Welding case study using Temperature Controlled Robotics with a HPDC Cylinder Block and dissimilar materials joining
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2019 (English)In: Journal of Manufacturing Processes, ISSN 1526-6125, Vol. 46, p. 177-184Article in journal (Refereed) Published
Abstract [en]

The automotive industry is going through a radical transformation from combustion engines to fully electric propulsion, aiming at improving key performance indicators related to efficiency, environmental sustainability and economic competitiveness. In this transition period, it is important to continue the innovation of combustion engines for e.g. plug-in hybrid vehicles. This led Volvo Cars to pursue radically new manufacturing processes such as Friction Stir Welding (FSW). The work presented in this paper is a case study whereby feasibility of using FSW to join a reinforcement element into the aluminium casted Cylinder Block was studied. The complex geometry of the joint required a flexible five-axis manipulator, i.e. an industrial robot, as well as advanced process control, i.e. temperature feedback control, in order to maintain a consistent weld quality throughout the whole component. The process was successfully demonstrated in a lab environment and offers a cost-efficient solution while maintaining the durability and higher efficiency. The outcome of this study shows the great potential of implementing the FSW process in combination with High Pressure Die Casted components, such a Cylinder Block. © 2019 The Society of Manufacturing Engineers

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Aluminum; Automotive industry; Benchmarking; Casting; Combustion; Competition; Cylinder blocks; Dissimilar materials; Efficiency; Friction; Friction stir welding; Industrial manipulators; Intelligent control; Manipulators; Plug-in hybrid vehicles; Research laboratories; Robots; Sustainable development; Temperature control, Advanced Process Control; Automotive; Economic competitiveness; Environmental sustainability; Friction stir welding(FSW); Key performance indicators; Manufacturing process; Radical transformation, Process control
National Category
Manufacturing, Surface and Joining Technology Robotics
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-14487 (URN)10.1016/j.jmapro.2019.08.012 (DOI)2-s2.0-85072050179 (Scopus ID)
Available from: 2019-10-01 Created: 2019-10-01 Last updated: 2019-10-01
Ferreira Magalhães, A. C., De Backer, J., Martin, J. & Bolmsjö, G. (2019). In-situ temperature measurement in friction stir welding of thick section aluminium alloys. Journal of Manufacturing Processes, 39, 12-17
Open this publication in new window or tab >>In-situ temperature measurement in friction stir welding of thick section aluminium alloys
2019 (English)In: Journal of Manufacturing Processes, ISSN 1526-6125, Vol. 39, p. 12-17Article in journal (Refereed) Published
Abstract [en]

Friction stir welding (FSW) is a reliable joining technology with a wide industrial uptake. However, several fundamentals of the process such as the temperature inside the stirred zone of the weld and its influence on mechanical properties, are not yet fully understood. This paper shows a method for accurate temperature measurements in multiple locations around the tool, to identify the location of the peak temperature, the temperature variations between the advancing and the retreating side of the tool and its relation to the tool geometry. Both standardised thermocouples in the FSW tool and the novel "tool-workpiece thermocouple" method were used to record temperatures.Bead-on-plate welds in 20 mm thickness AA6082-T6 were produced while the temperatures were measured in three locations on the FSW tool: at the shoulder outer diameter, at the transition from shoulder to probe and at the probe tip. It was found that the hottest point in the stirred zone was 607 °C and was located at the transition between the shoulder and probe, on the retreating-trailing side of the tool. The lowest temperature was found at the probe tip on the retreating-leading side of the tool.The results offer a better understanding of the temperature distribution around a FSW tool. The method presented can be applied to verification of thermal simulation models, tool design optimization, quality assurance and temperature feedback control.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Friction stir welding, Temperature measurement, Aluminium alloys, Thick section, Thermocouple, TWT
National Category
Materials Engineering
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-13705 (URN)10.1016/j.jmapro.2019.02.001 (DOI)000464296700002 ()2-s2.0-85061529967 (Scopus ID)
Funder
Region Västra Götaland, RUN 612-0254-15Knowledge Foundation, 20140130Swedish Agency for Economic and Regional Growth, 20200328
Available from: 2019-03-06 Created: 2019-03-06 Last updated: 2019-05-10Bibliographically approved
Bolmsjö, G., Ferreira Magalhães, A. C., Cederqvist, L. & De Backer, J. (2018). Robotic Friction Stir Welding of complex geometry and mixed materials. In: 50th International Symposium on Robotics, ISR 2018: . Paper presented at 50th International Symposium on Robotics, ISR 2018; Messe Munchen East EntranceMunich; Germany; 20 June 2018 through 21 June 2018 (pp. 35-41). VDE Verlag GmbH
Open this publication in new window or tab >>Robotic Friction Stir Welding of complex geometry and mixed materials
2018 (English)In: 50th International Symposium on Robotics, ISR 2018, VDE Verlag GmbH , 2018, p. 35-41Conference paper, Published paper (Refereed)
Abstract [en]

Friction stir welding (FSW) is a solid state process for joining materials which has demonstrated advantages compares with other methods which include joining of mixed materials, hard to weld alloys and consistent and high quality. This paper presents a study of robotic FSW initiated by Volvo Skövde plant to join an insert workpiece of extruded aluminium with a cylinder block of aluminium casting. A three-stage procedure was decided to determine the feasibility to apply robotic FSW. The stages included study of welding the mixed materials, weld along the complex joint line with holes and channels close to the joint, and finally welding the cylinder block. The results based on preliminary analysis indicate that the final tests were successful and the process is feasible for the challenging case study. However, further studies are recommended in order to identify the operating parameters window, tool design, and control of the process in order to optimize productivity and quality. © VDE VERLAG GMBH

Place, publisher, year, edition, pages
VDE Verlag GmbH, 2018
Keywords
Aluminum castings, Cylinder blocks, Cylinders (shapes), Die casting inserts, Friction, Joining, Quality control, Research laboratories, Robotics, Welds, Complex geometries, Friction stir welding(FSW), Joining materials, Mixed materials, Operating parameters, Preliminary analysis, Robotic friction stir welding, Solid-state process, Friction stir welding
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-13431 (URN)2-s2.0-85059384869 (Scopus ID)978-3-8007-4699-6 (ISBN)
Conference
50th International Symposium on Robotics, ISR 2018; Messe Munchen East EntranceMunich; Germany; 20 June 2018 through 21 June 2018
Available from: 2019-01-21 Created: 2019-01-21 Last updated: 2019-04-23Bibliographically approved
Silva, A., De Backer, J. & Bolmsjö, G. (2017). Temperature measurements during friction stir welding. The International Journal of Advanced Manufacturing Technology, 88(9-12), 2899-2908
Open this publication in new window or tab >>Temperature measurements during friction stir welding
2017 (English)In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 88, no 9-12, p. 2899-2908Article in journal (Refereed) Published
Abstract [en]

The increasing industrial demand for lighter, more complex and multi-material components supports the development of novel joining processes with increased automation and process control. Friction stir welding (FSW) is such a process and has seen a fast development in several industries.This welding technique gives the opportunity of automation and online feedback control, allowing automatic adaptation to environmental and geometrical variations of the component.Weld temperature is related to the weld quality and therefore proposed to be used for feedback control. For this purpose, accurate temperature measurements are required. This paper presents an overview of temperature measurement methods applied to the FSW process. Three methods were evaluated in this work: thermocouples embedded in the tool, thermocouples embedded in the workpiece and the tool-workpiece thermocouple(TWT) method. The results show that TWT is an accurate and fast method suitable for feedback control of FSW.

Keywords
Friction stir welding, TWT method, temperature, aluminium, thermocouples
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-9531 (URN)10.1007/s00170-016-9007-4 (DOI)000394323600047 ()2-s2.0-84973646335 (Scopus ID)
Funder
Region Västra Götaland, RUN 612-0254-15
Note

Funders: Swedish Agency for Economic and Regional Growth through European Regional Development Fund, 20200328

Available from: 2016-07-08 Created: 2016-07-08 Last updated: 2019-05-23Bibliographically approved
Silva, A., De Backer, J. & Bolmsjö, G. (2017). Welding Temperature during FSW of 5 mm thickness AA6082-T6. In: 5th international conference on scientific and technical advances on friction stir welding & processing, Metz, France, 11-13 October 2017.: . Paper presented at 5th international conference on scientific and technical advances on friction stir welding & processing, Metz, France, 11-13 October 2017..
Open this publication in new window or tab >>Welding Temperature during FSW of 5 mm thickness AA6082-T6
2017 (English)In: 5th international conference on scientific and technical advances on friction stir welding & processing, Metz, France, 11-13 October 2017., 2017Conference paper, Oral presentation only (Other academic)
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-14369 (URN)
Conference
5th international conference on scientific and technical advances on friction stir welding & processing, Metz, France, 11-13 October 2017.
Available from: 2019-09-03 Created: 2019-09-03 Last updated: 2019-09-03Bibliographically approved
Silva, A., De Backer, J. & Bolmsjö, G. (2016). Analysis of Plunge and Dwell Parameters of Robotic FSW Using TWT Temperature Feedback Control. In: Proceedings of 11th International Symposium on Friction Stir Welding: . Paper presented at 11th International Symposium on Friction Stir Welding, Cambridge, UK, 17-19 May, 2016 (pp. 1-11). Cambridge, UK
Open this publication in new window or tab >>Analysis of Plunge and Dwell Parameters of Robotic FSW Using TWT Temperature Feedback Control
2016 (English)In: Proceedings of 11th International Symposium on Friction Stir Welding, Cambridge, UK, 2016, p. 1-11Conference paper, Published paper (Other academic)
Abstract [en]

Friction stir welding (FSW) and variants of the process have generated high interest in many industries due to its several advantages such as low distortion, superior mechanical properties over arc welding and the possibility of joining dissimilar materials. Increased complexity of industrial applications require a better control of the welding process in order to guarantee a consistent weld quality. This can be achieved by implementing feedback control based on sensor measurements. Previous studies have demonstrated a direct effect of weld temperature on the mechanical properties of FSW joints, [1], and therefore, temperature is chosen as primary process variable in this study.A new method for temperature measurement in FSW referred to as the Tool-WorkpieceThermocouple (TWT) method has recently been developed by De Backer. The TWT method is based on thermoelectric effect and allows accurate, fast and industrially suitable temperature monitoring during welding, without the need for thermocouples inside the tool [2].This paper presents an application of the TWT method for optimisation of the initial weld phases, plunge and dwell, operation in conventional FSW, which can also be applied to friction stir spot welding (FSSW). An analysis of the operation parameters by using feedback temperature control is presented aiming to better control of the initial weld phases through temperature feedback.

The introduction of the TWT temperature sensor provides additional process information during welding. Fast data acquisition gives opportunity to differentiate different process phases: contact of probe tip with workpiece surface; plunge phase; dwell phase. This would be followed by tool retraction for FSSW or tool traverse phase for FSW.The effect of the plunge parameters on weld temperature and duration of each phase were studied for the purpose of optimising the process with respect to process (i) robustness, (ii)time, (iii) robot deflection and (iv) quality. By using temperature feedback, it is possible to control the plunge phase to reach a predefined weld temperature, avoiding overheating of the material, which is known to have a detrimental influence on mechanical properties. The work presented in this paper is an important step in the optimization of robotic FSSW and FSW.

Place, publisher, year, edition, pages
Cambridge, UK: , 2016
Keywords
Plunging, Friction Stir Spot Welding, Temperature, TWT, Robot
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering; Production Technology
Identifiers
urn:nbn:se:hv:diva-9530 (URN)
Conference
11th International Symposium on Friction Stir Welding, Cambridge, UK, 17-19 May, 2016
Available from: 2016-07-08 Created: 2016-07-08 Last updated: 2018-08-12Bibliographically approved
De Backer, J., Martin, J. & Wei, S. (2016). Robotic Stationary Shoulder FSW: benefits and limitations. In: Conference proceedings of the 11th International Symposium on Friction Stir Welding: . Paper presented at 11th International Symposium on Friction Stir Welding, Cambridge, UK, 17-19 May, 2016.
Open this publication in new window or tab >>Robotic Stationary Shoulder FSW: benefits and limitations
2016 (English)In: Conference proceedings of the 11th International Symposium on Friction Stir Welding, 2016Conference paper, Oral presentation only (Refereed)
National Category
Robotics Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering; Production Technology
Identifiers
urn:nbn:se:hv:diva-9767 (URN)
Conference
11th International Symposium on Friction Stir Welding, Cambridge, UK, 17-19 May, 2016
Available from: 2016-08-16 Created: 2016-08-16 Last updated: 2018-08-12Bibliographically approved
Silva, A., De Backer, J. & Bolmsjö, G. (2015). Cooling rate effect on temperature controlled FSW process. In: : . Paper presented at IIW International Conference High-Strength Materials - Challenges and Applications, 2-3 July 2015, Helsinki, Finland, Helsingfors, 2015 (pp. 1-5). Helsinki, Finland
Open this publication in new window or tab >>Cooling rate effect on temperature controlled FSW process
2015 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

A continuous trend towards more demanding jointgeometries is imposed across various manufacturingindustries. During Friction Stir Welding (FSW) of suchcomplex geometries, the surrounding environment playsan important role on the final weld quality, especially inthermal aspects. In order to guarantee a consistent weldquality for different conditions, in-process weldingparameter adaptation is needed.This paper studies the effect of the cooling rate onmechanical properties for temperature controlled FSW byusing different backing bar materials. A new temperaturesensor solution, the Tool-Workpiece Thermocouple(TWT) method [1], was applied to measure thetemperature during welding. A FSW-robot equipped withtemperature and force feedback control was used, whererotation speed was varied to maintain a constant weldingtemperature. AA7075-T6 lap joints were performed withand without temperature control. The cooling rate duringwelding was acquired and macrographs and mechanicalproperties were evaluated for each weld. The rotationspeed offered a fast response promoting the heat inputnecessary to weld at the set temperature. Temperaturecontrolled welds presented a better behaviour undertensile loads. The results prove that temperature controlusing the TWT method is suitable to achieve higher jointquality and provides a fast setup of optimal parameters fordifferent environments.The work presented is an important step in the processoptimization through feedback control which willconsider not only the operational parameters of theprocess as such but also the resulting quality of the joint.

Place, publisher, year, edition, pages
Helsinki, Finland: , 2015
Keywords
Friction Stir weld, Cooling rate, TWT method, Temperature control, Aluminium alloy
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering; Production Technology
Identifiers
urn:nbn:se:hv:diva-9120 (URN)
Conference
IIW International Conference High-Strength Materials - Challenges and Applications, 2-3 July 2015, Helsinki, Finland, Helsingfors, 2015
Available from: 2016-02-25 Created: 2016-02-25 Last updated: 2018-08-12Bibliographically approved
Silva, A., De Backer, J. & Bolmsjö, G. (2015). TWT method for temperature measurement during FSW process. In: The 4th international Conference on scientific and technical advances on friction stir welding & processing: . Paper presented at The 4th international Conference on scientific and technical advances on friction stir welding & processing October 1-2, 2015 (pp. 95-98). San Sebastian, Spain
Open this publication in new window or tab >>TWT method for temperature measurement during FSW process
2015 (English)In: The 4th international Conference on scientific and technical advances on friction stir welding & processing, San Sebastian, Spain, 2015, p. 95-98Conference paper, Published paper (Refereed)
Abstract [en]

Friction stir weld (FSW) has generated a high interest in many industry segments in the past 20 years. Along with new industrial challenges, more complex geometries and high quality demands, a better control of the welding process is required. New approaches using temperature controlled welding have been proposed and revealed good results. However, few temperature measurement methods exist which are accurate, fast and industrially suitable. A new and simple sensor solution, the Tool-Workpiece Thermocouple (TWT) method, based on the thermoelectric effect was recently developed.This paper presents a calibration solution for the TWT method where the TWT temperature is compared to calibrated thermocouples inside the tool. The correspondence between both methods is shown. Furthermore, a calibration strategy in different aluminium alloys is proposed, which is based on plunge iterations. This allows accurate temperature monitoring during welding, without the need for thermocouples inside the tool.

Place, publisher, year, edition, pages
San Sebastian, Spain: , 2015
Keywords
Friction stir welding, TWT method, Temperature measurements, Aluminium alloys
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering; Production Technology
Identifiers
urn:nbn:se:hv:diva-9122 (URN)
Conference
The 4th international Conference on scientific and technical advances on friction stir welding & processing October 1-2, 2015
Available from: 2016-02-25 Created: 2016-02-25 Last updated: 2018-08-12Bibliographically approved
De Backer, J. & Bolmsjö, G. (2014). Deflection model for robotic friction stir welding. Industrial robot, 41(4), 365-372
Open this publication in new window or tab >>Deflection model for robotic friction stir welding
2014 (English)In: Industrial robot, ISSN 0143-991X, E-ISSN 1758-5791, Vol. 41, no 4, p. 365-372Article in journal (Refereed) Published
Abstract [en]

Purpose - This paper aims to present a deflection model to improve positional accuracy of industrial robots. Earlier studies have demonstrated the lack of accuracy of heavy-duty robots when exposed to high external forces. One application where the robot is pushed to its limits in terms of forces is friction stir welding (FSW). This process requires the robot to deliver forces of several kilonewtons causing deflections in the robot joints. Especially for robots with serial kinematics, these deflections will result in significant tool deviations, leading to inferior weld quality. Design/methodology/approach - This paper presents a kinematic deflection model, assuming a rigid link and flexible joint serial kinematics robot. As robotic FSW is a process which involves high external loads and a constant welding speed of usually below 50 mm/s, many of the dynamic effects are negligible. The model uses force feedback from a force sensor, embedded on the robot, and predicts the tool deviation, based on the measured external forces. The deviation is fed back to the robot controller and used for online path compensation. Findings - The model is verified by subjecting an FSW tool to an external load and moving it along a path, with and without deviation compensation. The measured tool deviation with compensation was within the allowable tolerance for FSW. Practical implications - The model can be applied to other robots with a force sensor. Originality/value - The presented deflection model is based on force feedback and can predict and compensate tool deviations online.

Keywords
Force control;Force control, Deflection model, Friction stir welding, Path compensation, Robot welding
National Category
Production Engineering, Human Work Science and Ergonomics
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:hv:diva-6735 (URN)10.1108/IR-01-2014-0301 (DOI)000341784300006 ()
Funder
Knowledge Foundation
Available from: 2014-10-02 Created: 2014-10-02 Last updated: 2018-07-25Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-9553-7131

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