Effect of niobium interlayer in dissimilar friction stir welding of aluminum to titanium

Kar, Amlan and Choudhury, Sounak K and Suwas, Satyam and Kailas, Satish V (2018) Effect of niobium interlayer in dissimilar friction stir welding of aluminum to titanium. In: MATERIALS CHARACTERIZATION, 145 . pp. 402-412.

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Abstract

The most important issue associated with dissimilar welding is the formation of detrimental intermetallics and consequent reduction in mechanical properties of the weld. It was expected that addition of an interlayer would modify the pattern of the intermetallic formation. The present investigation deals with Friction Stir Welding of aluminum (Al) to titanium (Ti) in presence of niobium (Nb) interlayer. X-ray Computed Tomography results highlighted that fine particles of both Ti and Nb are homogeneously distributed. Large Ti particles are substantially fragmented whereas large Nb particles remain as flakes. Microstructural features of the nugget zone indicated a complex mixing of materials. Jointing had been perceived through elemental diffusion at the interfaces of Al/Ti and Ti/Nb. However, Nb restricted the reaction between Al and Ti, and acted as an efficient interlayer to retard the formation of brittle Al3Ti intermetallic phase. Mechanisms of microstructural evolution in Al side of the weld have been identified as Dynamic Recovery, Dynamic Recrystallization and particle stimulated nucleation. Significant improvement in the tensile ductility had been observed due to the presence of finer particles. The presence of Nb in the weld nugget influences the microstructural evolution and tensile properties of the weld by reducing the formation of intermetallics.

Item Type:	Journal Article
Publication:	MATERIALS CHARACTERIZATION
Publisher:	ELSEVIER SCIENCE INC
Additional Information:	Copy right for this article belong to ELSEVIER SCIENCE INC
Keywords:	Friction stir welding; Interlayer; X-ray computed tomography; Intermetallics; Dynamic recrystallization; Mechanical properties
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	28 Nov 2018 15:13
Last Modified:	25 Aug 2022 04:30
URI:	https://eprints.iisc.ac.in/id/eprint/61179

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