Journal Published Online: 23 May 2019
Volume 8, Issue 4

Friction Stir Welding between 6082 and 7075 Aluminum Alloys Thermal Treated for Automotive Applications

CODEN: MPCACD

Abstract

The automotive industry demands ecofriendly manufacturing processes and lightweight structures and materials to reduce CO2 emissions and decrease weight and fuel consumption while optimizing overall performance. Aluminum alloys in the 7xxx and 6xxx series offer high potential for weight reduction in automotive and other transportation industries. 7xxx aluminum alloys have the best strength performance among all commercial aluminum alloys. Alloys in the 6xxx series generally have medium-to-high strength, high corrosion resistance, and good formability. Alloys in both the 7xxx and 6xxx series are strengthened by heat treatment. The increased strength-to-weight ratio and the thermal treatment processing open the possibility to use these alloys as possible alternative materials instead of steel in the automotive industry for the fabrication of car body parts. However, their poor formability and weldability are the main drawbacks when these alloys are considered as substitutes of steel and other dissimilar joints during the fabrication of car body parts and the production chain. Recently, Hot Forming and in-die Quenching (HFQ), a patented hot stamping process, has been introduced to manufacture complex-shaped high-strength heat-treatable aluminum alloys. The work described in this article is an experimental investigation of the weldability between AA6082 and AA7075 by Friction Stir Welding (FSW) that considers thermal treatments used during HFQ for automotive applications. The aforementioned FSW base metals, 6082 and 7075, are heat treated according to the solution heat treatment adopted during HFQ to evaluate the effect of the HFQ thermal cycle on the quality of the produced joints. Optical microscopy has been used to characterize the microstructure of the produced joints. The defect-free welded joints are characterized by good mechanical mixing between the joined materials as well as by grain refinement. The mechanical behavior of the produced welded joints was studied and compared with the parent materials, whereas the measured mechanical properties are correlated with the microstructure.

Author Information

Dragatogiannis, Dimitrios A.
Research Unit of Advanced, Composite, Nano-Materials and Nanotechnology, School of Chemical Engineering, National Technical University of Athens, Zografos, Athens, Greece
Kollaros, Dimitrios
Shipbuilding Technology Laboratory, School of Naval Architecture and Marine Engineering, National Technical University of Athens, Zografos, Athens, Greece
Karakizis, Panagiotis
Shipbuilding Technology Laboratory, School of Naval Architecture and Marine Engineering, National Technical University of Athens, Zografos, Athens, Greece
Pantelis, Dimitrios
Shipbuilding Technology Laboratory, School of Naval Architecture and Marine Engineering, National Technical University of Athens, Zografos, Athens, Greece
Lin, Jianguo
Department of Mechanical Engineering, Imperial College, 524 City and Guilds Building, South Kensington Campus, London, UK
Charitidis, Costas
Research Unit of Advanced, Composite, Nano-Materials and Nanotechnology, School of Chemical Engineering, National Technical University of Athens, Zografos, Athens, Greece
Pages: 19
Price: $25.00
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Details
Stock #: MPC20180179
ISSN: 2379-1365
DOI: 10.1520/MPC20180179