On tool stirring action in friction stir welding of work hardenable aluminium alloys

Abstract

In the paper solid state bonding conditions obtained in friction stir welding (FSW) of AA5754-H111 butt joints are analysed, considering the so called zigzag line in the transverse section of the joints. A wide experimental campaign was carried out varying both tool advancing speed and tool rotational one. The effects of the process on the mechanical properties of the joint were highlighted and micro-and macro-observations were used in order to explain the reasons of the enhanced mechanical properties found for the welded material. Numerical results derived from a FEM model previously developed by the authors were utilised to point out the different mechanical and metallurgical behavior of the obtained joints.

Material adhesion and stresses on friction stir welding tool pins

“…1,2 The role of tool shoulder has been extensively discussed in a recent review of FSW tools. 3 In the previous studies of pin geometry, [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] emphasis has been placed on the testing and characterisation of welds. Apart from the pins of circular cross-section, 8,[17][18][19][20] various polygonal cross-sections such as triangle, [4][5][6][7][8] square, [9][10][11][12][13][14][15][16] and hexagon 21 shapes have been recommended in different studies for various welding conditions.…”

Monitoring of Weld Quality in Friction Stir Welding Based on Spindle Speed and Motor Current Signals

“…UTS, YS, and E were reported to increase with the increase in the revolutionary pitch and then decrease after a certain value of the same. Similar reporting on the variation of weld quality in FSW process can be found in the related works by different researchers (Li and Liu 2013;Lim et al 2004;D'Urso et al 2009;Kamp et al 2009;Buffa et al 2013;Hamilton et al 2012;Miyazawa et al 2012). Researchers have presented the effect of various process parameters over the quality of the weld, but none has reported on the inconsistency of the weld quality over the same range of process parameters.…”

Bonding mechanism and interface characterisation during dissimilar friction stir welding of an aluminium/polymer bi-material joint

“…As seen in Fig.3a-band Fig.4a-d, FSW of the base Al-Mg alloy caused complete refinement of the initial coarse-grained structure, resulting in an average grain size <100 nm. These results indicate that the dissimilar FSW and the presence of HDPE material in the joint influences the grain structure of the AA5059 alloy significantly, as compared with the similar FSW of this alloy 4,10. In competition between the increasing temperature and…”

“…7 Consequently, similar or dissimilar joining of aluminium alloys and polymers and fabrication of a hybrid metal-polymer structure is required for construction of such large and complex parts or structures. 4,5,[8][9][10][11][12][13][14][15] Friction-stir welding (FSW) is a promising modified solid-state joining technique proposed with much advantages over the common fusion welding methods. 16,17 Similar joining of polymeric materials 18,19 and similar/dissimilar welding of different aluminium alloys 2,3,5,[10][11][12][13][20][21][22][23] by using FSW process have been examined to date.…”

“…4,5,[8][9][10][11][12][13][14][15] Friction-stir welding (FSW) is a promising modified solid-state joining technique proposed with much advantages over the common fusion welding methods. 16,17 Similar joining of polymeric materials 18,19 and similar/dissimilar welding of different aluminium alloys 2,3,5,[10][11][12][13][20][21][22][23] by using FSW process have been examined to date. Due to large dissimilarities in physical and chemical properties of the aluminium and polymer, their bonding using traditional joining techniques is more difficult.…”