Microstructural analysis of cooling tank-assisted hybrid friction stir welded aluminium alloys: a novel approach

Abstract

The friction stir welding process is a solid-state technique for joining similar and dissimilar alloys. The advanced fixture was designed and fabricated for welding of the aluminum plate by a hybrid fabricated fixture on a vertical milling center. The storage tank was designed and attached at the bottom of the base plate of the fixture. The three different cooling media used in the cooling tank as air, water, and coolant. The welded samples were examined for mechanical and metallurgical performance. The optimization of process parameters was done for the tensile Test as output. The coolant as a fluid in the tank results in maximum tensile strength at 500 rpm. The microstructural characterization of the heat-affected zone was also done. The weld thinning and quenching are the main problems of direct cooled FSW. This problem is not found in the indirect cooled FSW welding method. The storage tank provided uniform heating and cooling during welding that reduced the thermal quench and microstructural problems. The SEM and EDX mapping images showed the effect of different cooling media on the FSW samples. The microhardness was analyzed to identify different microstructural zone and the hardness of welded part.

Keywords:

• ICFSW-A
• ICFSW-W
• ICFSW-C
• FSW
• HAZ
• TMAZ
• SZ

Author contributions

Authors have equally contributed in the paper. The first author has carried out the research work under the supervision of the second author.

Acknowledgment

The authors gratefully acknowledges financial support from SERB received by the second author.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Science and Engineering Research Board [Grant No. SRG/2020/000183].