Influence of Welding Speed on Fracture Toughness of Friction Stir Welded AA2024-T351 Joints

Abstract

In order to ensure a quality welded joint, and thus safe operation and high reliability of the welded part or structure achieved by friction stir welding, it is necessary to select the optimal welding parameters. The parameters of friction stir welding significantly affect the structure of the welded joint, and thus the mechanical properties of the welded joint. Investigation of the influence of friction stir welding parameters was performed on 6-mm thick plates of aluminum alloy AA2024 T351. The quality of the welded joint is predominantly influenced by the tool rotation speed n and the welding speed v. In this research, constant tool rotation speed was adopted n = 750 rpm, and the welding speed was varied (v = 73, 116 and 150 mm/min). By the visual method and radiographic examination, imperfections of the face and roots of the welded specimens were not found. This paper presents the performed experimental tests of the macro and microstructure of welded joints, followed by tests of micro hardness and fracture behavior of Friction Stir Welded AA2024-T351 joints. It can be concluded that the welding speed of v = 116 mm/min is favorable with regard to the fracture behavior of the analysed FSW-joint.

Study on tensile and fatigue failure in the low-hardness zone of AA2519-T62 FSW joint

“…It should be noted that its microhardness is relatively high (107-113 HV0.1) and significantly differs from other literature reports, mostly around 85 HV0.1 [6,[23][24]. The reasons for this should be seen in the use of a relatively low value of tool rotational speed (400 rpm), which significantly reduces the amount of heat affecting the welded material [1,18]. The dominant phenomenon in the formation of the low hardness zone is the overaging of the strengthening phase [23].…”

“…In FSW of a precipitation-hardened aluminum alloy, a relatively high reduction of mechanical properties is expected, predominantly due to an overaging of strengthening phases [8,15]. For this reason, a lot of effort is put into studies on FSW of 2XXX and 7XXX alloys in terms of welding parameters optimization [16][17][18] including also different cooling media [19] and joints post-processing [20][21][22].…”

Mechanical and Microstructural Characterization of Friction Stir Welded SiC and B4C Reinforced Aluminium Alloy AA6061 Metal Matrix Composites

“…Though a solid-state joining process with the absence of material melting, FSW reveals a lack of stimulated melt solidified structure in the weld zone. This addresses the technical lacuna’s encountered during the fusion welding of composites [ 11 , 12 , 13 , 14 , 15 , 16 ]. A few impactful literature related to the FSW of Al-MMCs has been reported [ 17 , 18 , 19 , 20 , 21 , 22 ].…”