Time-dependency of mechanical properties and component behavior after friction stir welding
- 20 Downloads
This paper reports on the time dependency of mechanical properties and component behavior during the first hours after friction stir welding (FSW). Three different aluminum alloys, two age-hardened alloys AA 6014-T4 and 6016-T4 and as a reference 5182-O/H111, are welded and samples are taken from the steady-state region immediately. Those samples are examined at various time intervals by means of tensile and hardness testing to quantify local properties and their recovery over time. Initially, the FSW process leads to a significant reduction in mechanical properties of the age-hardened alloys and to an altered, time-dependent component behavior as opposed to the base material. For AA 6014 and 6016, all mechanical properties recover significantly within a few hours after welding, whereby the gradient is initially very steep and levels out after 1–2 days. Gradients of up to 6 MPa/h and relative increases of more than 25% are observed for ultimate tensile strength within the first 2 days. As such, the increase in strength within the heat-affected zone and with it the entire welded component can be compared to natural aging after solution annealing. The results show the importance of considering the time dependency for weld qualification and also for comparing studies of age-hardenable alloys.
KeywordsFriction stir welding Time-dependent component behavior Recovery and evolution of mechanical properties Weld qualification
Unable to display preview. Download preview PDF.
The author thanks Andrea Gommeringer, Oliver Volz, and Rudi Scheck for their great flexibility and effort regarding some of the time-critical experimental work.
Parts of this study was supported by the German Research Foundation (DFG) Project RO 651/16-1.
- 3.Borchers H, Schwarzmaier W (1943) Der einfluß nachträglicher wärmebehandlung auf den aushärtungzustand einer aluminium-magnesium-silicium-legierung. Z Metallkund 35:237–242Google Scholar
- 4.Brenner P, Kostron H (1939) Über die vergütung der aluminium-magnesium-silizium-legierungen (pantal). Z Metallkund 31:89–97Google Scholar
- 9.Haase C, Wurst H (1941) Zur frage der kalt- und warmaushärtung bei aluminium-magnesium-silizium-legierungen. Z Metallkund 33:399–403Google Scholar
- 11.Hossfeld M (2016a) Experimental, analytical and numerical investigations of the friction stir welding process. PhD thesis, University of Stuttgart. https://doi.org/10.18419/opus-8957
- 12.Hossfeld M (2016b) A fully coupled thermomechanical 3D model for all phases of friction stir welding. In: 11th international symposium on friction stir welding. https://doi.org/10.18419/opus-8845
- 13.Hossfeld M, Roos E (2013) A new approach to modelling friction stir welding using the CEL method. Advanced Manufacturing Engineering and Technologies NEWTECH, pp 179–190. https://doi.org/10.18419/opus-8825
- 14.Huppert-Schemme G (1996) AlMgSi-Bleche für den Fahrzeugbau. Aluminium-VerlagGoogle Scholar
- 15.ISO 25239-4 (2011) Friction stir welding - aluminium - part 4: specification and qualification of welding procedures (ISO 25239-4:2011)Google Scholar
- 16.Mishra RS, De PS, Kumar N (2014) Friction stir welding and processing. Springer International Publishing. https://doi.org/10.1007/978-3-319-07043-8
- 18.Olea CAW (2008) Influence of energy input in friction stir welding on structure evolution and mechanical behaviour of precipitation-hardening in aluminium alloys (AA2024-T351, AA6013-T6 and Al-Mg-Sc). GKSS-Forschungszentrum GeesthachtGoogle Scholar
- 21.Rahimzadeh Ilkhichi A, Soufi R, Hussain G, Vatankhah Barenji R, Heidarzadeh A (2015) Establishing mathematical models to predict grain size and hardness of the friction stir-welded AA 7020 aluminum alloy joints. Metall and Mater Trans B 46(1):357–365. https://doi.org/10.1007/s11663-014-0205-x CrossRefGoogle Scholar