New insight into the phenomenon of the abnormal grain growth in friction-stir welded aluminum

Numerical Simulation of the Thermo-Mechanical Behavior of 6061 Aluminum Alloy during Friction-Stir Welding

“…The work shown in this paper is a part of a wide-ranging research project aiming to investigate of the effect of FSW on the microstructure and mechanical properties of 6061 aluminum alloy. In previous studies [40][41][42], the detailed examinations showed an inhomogeneous microstructure distribution in the stir zone (Microstructural characterization of the studied welds is shown in supplementary data "Microstructure".). Moreover, it was found that such microstructural gradients may promote abnormal grain growth during the post-weld heat treatment of FSW joints [41,42].…”

“…In previous studies [40][41][42], the detailed examinations showed an inhomogeneous microstructure distribution in the stir zone (Microstructural characterization of the studied welds is shown in supplementary data "Microstructure".). Moreover, it was found that such microstructural gradients may promote abnormal grain growth during the post-weld heat treatment of FSW joints [41,42]. To elucidate the origin of such a microstructure, it is necessary to know the local variation in thermomechanical conditions within the stir zone.…”

Suppression of abnormal grain growth in friction-stir welded aluminum by pre-strain rolling: Limitation of the approach

“…The relatively low stability of welded materials against abnormal grain growth is often considered a significant problem in friction-stir welding/processing (FSW/P) of aluminum alloys [1,2]. This phenomenon typically occurs during either post-weld solutionizing treatment or superplastic deformation and involves a catastrophic coarsening of a few grains which rapidly consume the almost entire weld zone [2][3][4][5][6][7]. This undesirable effect is usually explained in terms of the cellular Humphreys' theory [8] being attributed to a synergetic effect of grain refinement and dissolution of second-phase particles [e.g.…”

A review of effect on metallurgical properties of friction stir welding using high entropy alloy

“…Aluminum and its alloys were the first metal used in Friction Stir Welding [4]. Aluminum and most of its alloys carrying 1000x-7000x series are widely researched and studied in FSW [4][5][6][7][8][9][10]. Friction Stir Welding is solid-phase welding using a rotational tool having a cylindrical shoulder and pin within it.…”

“…Result of which is no solidification defect [3]. Till now, Friction Stir Welding has evolved a lot, from machine design to the work piece's joint strength, hardness, corrosion resistance, microstructure, and FSW effect on different alloys and metals affecting grain properties [9][10]. FSW has undertaken various similar or dissimilar alloys welding providing efficient joints.…”