A feasible operational parameter window for enhancement of welding speed in friction stir welding of 2195-T8 Al–Li alloy

Abstract

The improvement of the welding speed becomes extraordinarily difficult for the friction stir welding (FSW) of Al-Li alloys with medium thickness (5-10 mm). In this study, 2195-T8 Al alloy plates with a thickness of 6 mm were subjected to FSW under different welding speeds of 200-800 mm/min with the objective of seeking an optimised welding parameter. The tensile strength of ∼ 422 MPa at a relatively high welding speed of 400 mm/min with a tool rotational speed of 800 rpm was obtained, which reached a comparable level to those of the joints with low welding speeds. The combination of moderate tool rotational speed and moderate welding speed was a feasible optimising direction for FSW of Al-Li alloy with medium thickness.

A comparative study of microstructure and mechanical properties of conventional and synergistic double-sided FSW joints of 6061 zxaluminium alloy

“…A very limited band of elongated grains can be seen next to the SZ, which is known as the TMAZ. Outside of the TMAZ is the HAZ, which solely experiences thermal cycling without any plastic deformation [11,23,24].

Figure 2 Cross-sectional morphologies of joints: (a, c, e, g, and i) corresponding to parameters 1–5 of SDS-FSW joints and (b, d, f, h, and j) corresponding to parameters 6–10 of DS-FSW joints.

Figure 3 EBSD results of different zones: (a) and (e) SZ for the first weld of DS-FSW joint, (b) and (f) SZ for the second weld of DS-FSW joint, (c) and (g) SZ of SDS-FSW joint, and (d) and (h) BM.

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“…A very limited band of elongated grains can be seen next to the SZ, which is known as the TMAZ. Outside of the TMAZ is the HAZ, which solely experiences thermal cycling without any plastic deformation [11,23,24].…”