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Effects of Post Weld Aging on the Mechanical Properties and Microstructure of TIG and MIG Welded AA 7075

  • Sami Sayer
Published/Copyright: May 26, 2013
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Abstract

In this study, the effect of post-weld artificial aging has been investigated on Tungsten Inert Gas (TIG) and Metal Inert Gas (MIG) welds of Aluminum Alloy 7075 (AA 7075). Artificial aging has been carried out for several durations at a temperature of 125 °C. In order to study the effect of post-weld aging, microstructural examination, hardness measurements and room temperature tensile tests have been carried out. The results show that TIG and MIG welding caused an increase in grain size in the HAZ and the weld metal as compared to the base material. After post-weld aging, it turned out that the mechanical properties of MIG welds increased while those of TIG welds decreased for the same aging conditions, compared to as-welded joints, while the grain sizes are not significantly affected from the aging process.

Kurzfassung

Für den vorliegenden Beitrag wurde der Effekt einer künstlichen Alterungs-Nachwärmung an Wolfram Inert Gas (WIG)- und Metall Inert Gas (MIG)- Schweißungen der Aluminiumlegierung AA 7075 untersucht. Die künstliche Alterung wurde über verschiedene Zeiten bei einer Temperatur von 125 °C ausgeführt. Um die Wirkung der Nachwärmung zu bestimmen, wurden Gefügeuntersuchungen, Härtemessungen und Zugversuche bei Raumtemperatur durchgeführt. Die Ergebnisse zeigen, dass die Korngröße in der Wärmeeinflusszone und im Schweißgut gegenüber dem Grundwerkstoff zunimmt. Nach der Alterungs-Nachwärmung nahmen bei denselben Bedingungen die mechanischen Eigenschaften in den MIG-Schweißungen zu, während sie in den WIG-Schweißungen reduziert wurden. Die Korngrößen wurden durch den Alterungsprozess nicht signifikant verändert.


Dr.-Ing. Sami Sayer, born 1959, studied Mechanical Engineering at the Ruhr University in Bochum, Germany, and obtained his doctoral degree at the Ege University in Turkey working on Friction Stir Welding on AA 6063(AlMgSi0.5) Aluminum alloys. He worked from 1988 to 1989 as construction engineer at Busch in Lörrach, Germany, and from 1991 to 2000 as product development engineer, from 2000 to 2002 as product development manager at Arçelik in Turkey. Since 2002 he is lecturer at the Ege University in Turkey.


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Published Online: 2013-05-26
Published in Print: 2008-09-01

© 2008, Carl Hanser Verlag, München

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