Effect of Tool Rotational Speed and Mechanisms Associated with Microstructure Evolution and Intermetallics Formation in Friction Stir Welding of Aluminum Alloy to Titanium Alloy

Kar, A and Singh, K and Kumar, L (2023) Effect of Tool Rotational Speed and Mechanisms Associated with Microstructure Evolution and Intermetallics Formation in Friction Stir Welding of Aluminum Alloy to Titanium Alloy. In: Journal of Materials Engineering and Performance .

PDF jou_lon_mat_soc_2023.pdf - Published Version Restricted to Registered users only Download (2MB) | Request a copy

Abstract

Friction stir welding (FSW) is a promising technology for joining dissimilar metal alloys, such as aluminum alloy (Al 2024) and titanium alloy (Ti-6Al-4V). However, optimizing FSW parameters to enhance joint strength and reliability remains a challenge. To address this, this manuscript presents a novel concept of using tool rotational speed as a key parameter to investigate joint formation mechanisms and associated mechanisms in FSW. The study found that tool rotational speed significantly affects the deformation and mechanical mixing of the two metals in the weld nugget. Optimal tool rotational speed produces a defect-free weld with superior mechanical properties. The fragmentation of joint interfaces and the formation of new particles of different sizes in titanium lead to deformation and fracture mechanisms. X-ray tomography results demonstrate that fine particles are evenly dispersed in the Al matrix compared to coarse particles. Moreover, the study provides valuable insights into the microstructural development in Al, attributed to dynamic recovery (DRV), continuous dynamic recrystallization (CDRX), and particle-stimulated nucleation (PSN). The type of intermetallic compounds (IMCs) formation is not affected by the tool rotational speed, and a proposed mechanism of IMCs formation is presented from a thermodynamic perspective. Overall, this study improvises the current understanding of joint formation mechanisms in FSW and suggests using tool rotational speed as a parameter for optimizing FSW parameters for enhanced joint strength and reliability.

Item Type:	Journal Article
Publication:	Journal of Materials Engineering and Performance
Publisher:	Springer
Additional Information:	The copyright for this article belongs to Springer.
Keywords:	adiabatic shear bands; dissimilar alloys; friction stir welding; joint formation mechanism; tensile strength; tool rotational speed; x-ray tomography
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	15 Jul 2023 07:10
Last Modified:	15 Jul 2023 07:10
URI:	https://eprints.iisc.ac.in/id/eprint/82475

Actions (login required)

View Item