Mikrostrukturelle, mechanische und korrosive Eigenschaften reibrührgeschweißter Stumpfnähte in Aluminiumlegierungen

Abstract

Das Reihriihrachwcil~cn (friction \tir welding FSW) ist cin ncues Fiigeverfahren, init dcm such die achwer schiiielzscliweil~b~iren, hiiherfesten Aluminitimlegiertiiigeii ohnc grolk Festigkeitsverluste verschwci0t werden kiinncn. Erstc Ergebniw von Untcrsuchungen an sc I bs t hergea t el I ten FS W -S t um pfnii h ten der A I u mi n i um Icgierungen 2024-T3 und 60 I3-T4 werden vorgcstellt. Zuniichst wird das Gefiige der Naht und der Wiirmeeintlul~zone mikrostrukturell und durch Hiirtcvcrliiufe charakterisiert. Weitcrhin wird rnit Zug-, Schwingfestigkeits-und Ril.ifortscliritlsver~uclicn nachgewiesen, daB insbesondere die FSW-Niihte der Legicrung 2024-T3 aulierordentlich Iiohc mechanische Belaslungen crtragen. Ab-schlieRende Korrosionsuntersuchungcii dcr FSW-Niihte xigen c Anliilligkeit der ~ibschrcckciiipfiiiclliehen Legierung r interkristallinc Korrosion und Schiclitkorrosion.

Local melting and cracking in Al 7075-T6 and Al 2024-T3 friction stir spot welds

“…The remarkable decrease in estimated strain rate values in friction stir spot welds made using high tool rotational speed settings was associated with spontaneous melting of second phase particles (g, S and T phases), which promoted tool slippage at the contact interface between the periphery of the rotating tool and adjacent material in the stir zone. Metallographic evidence confirming local melted film formation has been reported by numerous investigators when examining Al 7010, Al 2524 and Al 2024-T3 friction stir seam welds, 1,2,6 dissimilar Al 1050-AZ31 and Al 2024-Al 2014/Al 2 O 3 friction stir seam welds, 7,8 Al 6061/Al 2 O 3 plunge tests, 9 AZ31 and AZ91 friction stir spot welds 10,11 and dissimilar Al 6111/AZ91 friction stir spot welds. 12 It is difficult to reconcile the apparent contradictions in the published literature regarding measured stir zone temperature values, local melting and the absence of cracking in completed friction stir seam and friction stir spot welds.…”

Friction stir welding of aluminium alloys

“…384 A great deal of attention has been focused on the Cu containing 2xxx and 7xxx series (e.g. 2024, 48,[385][386][387][388][389][390] 7010, 7050, 7075), 385,388,[391][392][393] which show that the nugget becomes sensitised (Table 4). The severe themomechanical processing refines the grain structure and alters the precipitation distribution and chemistry, particularly near the grain boundaries (Tables 4 and 5).…”

Characterization of a friction-stir-welded aluminum alloy 6013

“…[8,10,20,[28][29][30][31] This is in agreement with observations made by other authors. [6,[8][9][10][11][13][14][15]20] The small equiaxed dynamic recrystallization (DRX) has taken place during FSW because of deformation and temperature, which may grains of the weld nugget were also found in the TEM foils ( Figure 3). The interiors of such grains are composed of gated.…”

“…However, the microstructural changes that occur MODERN aerospace concepts demand reductions in during the FSW process combined with the mechanical propboth the weight as well as the cost of the production of erties after welding are only now being reported. [6,[8][9][10][11][12][13][14][15][16] Modmaterials. Therefore, welding processes have proven most eling is presently used to explain the physical and mechanical attractive, and programs have been set up to study their details of the FSW process.…”