Computational analysis of inter-material mixing and weld-flaw formation during dissimilar-filler-metal friction stir welding (FSW). Issue 3 (12th October 2015)

• Record Type: Journal Article
• Authors: Grujicic, M.; Yavari, R; Ramaswami, S.; Snipes, J; Galgalikar, R
• Is Part Of: Multidiscipline modeling in materials and structures. Volume 11:Issue 3(2015)
• Page Start: 322
• Page End: 349
• Publication Date: 2015-10-12
• Subjects: Friction stir welding -- Finite element analysis -- Finite element method -- Process modelling -- Dissimilar-filler-metal -- Combined Eulerian-Lagrangian; Materials -- Mathematical models -- Periodicals; Engineering -- Mathematical models -- Periodicals; 620.11015118
• DOI: 10.1108/MMMS-12-2014-0062
• Languages: English
• ISSNs: 1573-6105

Abstract

Abstract : Purpose: – Friction stir welding (FSW) butt-joining involving the use of a dissimilar filler metal insert between the retreating and advancing portions of the workpiece is investigated computationally using a combined Eulerian-Lagrangian (CEL) finite element analysis (FEA). The emphasis of the computational analysis was placed on the understanding of the inter-material mixing and weld-flaw formation during a dissimilar-material FSW process. The paper aims to discuss these issues. Design/methodology/approach: – The FEA employed is of a two-way thermo-mechanical character (i.e. frictional-sliding/plastic-work dissipation was taken to act as a heat source in the energy conservation equation), while temperature is allowed to affect mechanical aspects of the model through temperature-dependent material properties. Within the analysis, the workpiece and the filler-metal insert are treated as different materials within the Eulerian subdomain, while the tool was treated as a conventional Lagrangian subdomain. The use of the CEL formulation within the workpiece insert helped avoid numerical difficulties associated with excessive Lagrangian element distortion. Findings: – The results obtained revealed that, in order to obtain flaw-free FSW joints with properly mixed filler and base materials, process parameters including the location of the tool relative to the centerline of the weld must be selected judiciously. Originality/value: – To the authors' knowledge, the present work is the first reported attempt to simulate FSW of dissimilar materials.