A review of microstructural changes occurring during FSW in aluminium alloys and their modelling

Abstract

Friction stir welding (FSW) process is currently considered as a promising alternative to join aluminium alloys. Indeed, this solid-state welding technique is particularly recommended for the assembly of these materials. Since parts are not heated above their melting temperature, FSW process may prevent solidification defects encountered in joining aluminium alloys and known as limitations to the dissemination of these materials in industries. During the past years, large literature has been devoted to the modelling of microstructural evolution in aluminium alloys during FSW processes and mainly dedicated to the analysis of precipitate evolutions and grain recrystallization mechanisms. Precipitate size distribution models have aroused widespread interest in recent years demonstrating their relevance to follow precipitation process in multicomponent alloys and multiphase systems. Efficient recrystallization models are also available and based on various grain growth mechanisms. In addition, multi-scale coupling strategies have recently emerged considering thermal, mechanical and metallurgical solutions. Consequently, the effect of FSW process parameters on weld properties is now investigated to determine optimized welding strategies regarding microstructure evolution. This research is based on reliable models reported in the literature enhancing the estimation of final weld state and associated properties as an answer to industrial needs. Validations of proposed modelling strategies have been reported based on in-depth analyses of experimental observations. This present work proposes a review of recent models dedicated to microstructural evolutions in aluminium alloys during FSW process. The interest and efficiency of current approaches will be discussed to highlight their limitations. Guidelines will propose new routes toward enhanced modelling strategies for future developments.

The Object Segmentation from the Microstructure of a FSW Dissimilar Weld

“…In most cases, these include various types of binarization, e.g., multi-criteria binarization with two thresholds [ 10 , 11 , 12 , 13 ], and also supportive processes of morphological image transformations [ 14 , 15 , 16 ], e.g., the processes of opening and closing [ 17 , 18 , 19 ]. A review of microstructural changes that occur during FSW in aluminum alloys and their modeling can be found in [ 20 , 21 , 22 ].…”

A numerical strategy to identify the FSW process optimal parameters of a butt-welded joint of quasi-pure copper plates: modeling and experimental validation

“…Many research studies have focused on the use of FSW to joint aluminum-based alloys, such as [4,5,6,29], while limited literature on dissimilar FSW of copper is available. The limited research on FSW, and consequently its industrial application, is due to both the high melting point and the good thermal conductivity of the cooper as they lead to increasing the heat input during the welding process to obtain a joint without defects.…”

Material flow and mechanical properties of friction stir welded Al-Mg-Si alloy: Role of concentric circles shoulder with non-circular pins

“…With this objective, several researchers have worked in optimizing the shoulder size and geometries such as plane, convex, and concave profiles for improving the properties of the weld. [6][7][8][9][10][11][12][13][14] Galvao et al 6 worked on the joining of 1 mm size copper sheets by varying the tool shoulder geometries. The designed scroll shoulder provided additional shearing action, which refined the grain size and improved the mechanical properties of the weld compared to the conventional flat or concave designs.…”