Study on governing parameters of thermal history during underwater friction stir welding

Papahn, Hossein; Bahemmat, Pouya; Haghpanahi, Mohammad; Sommitsch, Christof

doi:10.1007/s00170-014-6615-8

Cited by 35 publications

(16 citation statements)

References 23 publications

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“…Different configurations of ultrasonic equipment can be employed to measure RS. In each case, waves propagate through the solid after being launched by a transmitting transducer and are subsequently detected by a receiving transducer [16,18] (see Fig. 3).…”

Section: Experimental Procedures and Theorymentioning

confidence: 99%

“…In addition, Gachi et al [14,15] obtained the RS in AA7108 plates, joined by FSW, and observed the acousto-elastic effect that itself is due to the variation of ultrasonic wave velocity through the stressed materials. Finally, in 2014, the authors [16] proved the applicability and reliability of ultrasonic method for measuring RS induced by FSW process.…”

Section: Introductionmentioning

confidence: 95%

See 1 more Smart Citation

Effect of cooling media on residual stresses induced by a solid-state welding: underwater FSW

Papahn

Bahemmat

Haghpanahi

2015

Int J Adv Manuf Technol

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In this article, the effect of cooling media on the residual stresses (RS) induced by a solid-state welding process is scrutinized through measuring and comparing RS caused by friction stir welding (FSW) underwater and in open air using the non-destructive ultrasonic method for aluminum AA7075-T6. Underwater FSW as a solid-state welding method can extend the application of solid-state welding techniques in marine industry. Results reveal that the longitudinal and transverse RS reduce under the water compared to open air. This reduction in the longitudinal RS is the maximum within the nugget zone (about 17 %). Meanwhile, such reduction for the transverse RS reaches 70 % within the heat-affected zone. In addition, under both air and water, the longitudinal RS is several times greater than the transverse RS and is in tensile and compressive states inside and outside the nugget zone, respectively.

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Section: Experimental Procedures and Theorymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

Effect of cooling media on residual stresses induced by a solid-state welding: underwater FSW

Papahn

Bahemmat

Haghpanahi

2015

Int J Adv Manuf Technol

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“…For instance, in 2014, the authors showed that due to the higher cooling rate in underwater FSW, the weld becomes more brittle but the tensile strength is considerably increased. 8 Therefore, underwater FSW not only extend the submarine applications of solid-state methods, but also using water as the cooling media can considerably enhance the mechanical strength of the joints fabricated by FSW.…”

Section: Introductionmentioning

confidence: 99%

Study on residual stresses caused by underwater friction stir welding: FE modeling and ultrasonic measurement

Salimi

Bahemmat

Haghpanahi

2018

Proceedings of the Institution of Mechanical Engineers, Part E:

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Predicting residual stresses arising from the thermal and mechanical loading history during engineering processes including welding would be a viable tool to reach the optimum process parameters. In the present article, an elastothermo-visco-plastic model has been employed to estimate the residual stress caused by the underwater friction stir welding, which are resulted by large thermo-mechanical deformations on one hand and rapid cooling arising from the enormous non-uniform boiling heat convention of water on the other hand. Finally, the numerical results are compared with experimental data acquired by the ultrasonic method to evaluate the accuracy of the simulation process. Regarding the low temperature during underwater friction stir welding, the employed constitutive equations result in acceptable residual stress fields, while for in-air case, the amount of error increases significantly due to experience of high temperatures and intensification in hardening precipitation phenomena.

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“…The results showed that the peak temperature around tool shoulder is notably lowered and the tensile strength of the joint was improved by the cooling action. With the aim to take full advantage of external liquid cooling action, underwater friction stir welding of aluminum alloys was investigated by several researchers [7][8][9][10]. Compared with conventional FSW, it was found that the size of shoulder-affected zone was reduced and the strength improvement was acquired under the water cooling action.…”

Section: Introductionmentioning

confidence: 99%

Improving the structure-property of aluminum alloy friction stir weld by using a non-shoulder-plunge welding tool

M(王敏)

Zhang

et al. 2016

Int J Adv Manuf Technol

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In order to improve the joint performances by controlling the thermal effect of tool shoulder, a non-shoulderplunge (NSP) welding tool is utilized to conduct friction stir welding (FSW) of an Al-Mg aluminum alloy in this paper. Sound FSW joint is successfully produced by using the NSP welding tool. In contrast to conventional FSW (C-FSW), the thermal effect of tool shoulder is effectively reduced by NSP-FSW, leading to a significant size reduction of shoulderaffected zone in the joint. Besides, the NSP-FSW joint shows finer grain structures in the stir zone and thermo-mechanically affected zone, and exhibits lower extents of grain coarsening, dislocation polygonization, and particle dissolution in the heat-affected zone. Hardness maps show that the softening region width of NSP-FSW joint is only nearly half that of C-FSW joint and the NSP-FSW joint exhibits higher hardness in the heat-affected zone than C-FSW joint. The tensile test results indicate that the joint efficiency is improved from 89 % of C-FSW joint to 97 % by the NSP-FSW process.

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Study on governing parameters of thermal history during underwater friction stir welding

Cited by 35 publications

References 23 publications

Effect of cooling media on residual stresses induced by a solid-state welding: underwater FSW

Effect of cooling media on residual stresses induced by a solid-state welding: underwater FSW

Study on residual stresses caused by underwater friction stir welding: FE modeling and ultrasonic measurement

Improving the structure-property of aluminum alloy friction stir weld by using a non-shoulder-plunge welding tool

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