IWPDF2023

Fatigue Crack Growth Behavior of Friction Stir Welded SS304-Al5083 Dissimilar Joints

J. Nakrani 1 , W. Yan 2 , A. Shrivastava 1

1 Department of Mechanical Engineering, Indian Institute of Technology Bombay, Mumbai 400076, India 2 Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia

∗ jignesh.nakrani@monash.edu

Keywords: Fatigue crack growth behavior, Dissimilar weld, SS304, Al5083

Stainless steel and aluminum joints are desirable for weight reduction in applications like au tomotive and aerospace. These joints would be inevitably subjected to cyclic loading, which necessitates fatigue crack growth study of dissimilar joints. Friction stir welding is a solid-state joining technique, with proven potential for the fabrication of dissimilar joints. The objective of this work is to investigate the fatigue crack growth behavior of friction stir welded SS304-Al5083 joints. The SS304 and Al5083 sheets (250 mm x 80mm x 3 mm) are friction stir welded, using a tungsten carbide tool with 3 mm cylindrical pin diameter, 2.7 mm pin height and 16.5 mm shoul der diameter. The tensile and fatigue crack growth rate tests of the base materials and welded joints are performed. The fatigue crack growth rate of the welded joint is higher than both the base materials. Fractography of fractured specimens revealed a brittle failure of the welded joints and ductile failure for the base materials. Intermetallic compounds at the interface promote the brittle failure of welded specimens, which leads to a higher crack growth rate. To capture the influence of dissimilar material properties on fatigue crack growth behavior, an extended finite element method based numerical method is developed. The numerical simulation well captures the fatigue crack growth behavior of the dissimilar joints.

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