Study on mechanical properties and microstructure analysis of welded joints of 7A05 aluminum alloy by laser-MIG hybrid welding

DOI

10.2991/emeit.2012.324How to use a DOI?

Keywords

7A05 aluminum alloy, laser-MIG hybrid welding, mechanical properties, microstructure analysis

Abstract

7A05 aluminum alloy joints were fabricated by Laser-MIG hybrid welding, of which the tensile strength was tested at room temperature. The tensile fracture surfaces and microstructure were analyzed by SEM and TEM. The fracture surface analysis showed fracture morphologies of small dimple of 2 ~ 5m on the heat affected zone (HAZ) and big dimple of 30 ~ 50m on the weld bead. The fracture is inter-granular fracture with a small amount of cleavage fracture. TEM analysis showed that the HAZ region didn't exists '-phase, but Al3Zr, i.e., during welding thermal cycle, the joints appeared obvious '-phase back dissolved so that lost '-phase dispersion strengthening effect. O, Na and Fe impurities were detected in the joint, of which the crack originated during tensile testing. Both the impurities and '-phase back dissolved are responsible for the degrading of the welded joints mechanical properties.

Copyright

© 2012, the Authors. Published by Atlantis Press.

Open Access

This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

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TY  - CONF
AU  - Hongwei Liu
AU  - Jinglong Li
AU  - Zhihua Ma
AU  - Bing Ma
AU  - Shengqiang Feng
PY  - 2012/09
DA  - 2012/09
TI  - Study on mechanical properties and microstructure analysis of welded joints of 7A05 aluminum alloy by laser-MIG hybrid welding
BT  - Proceedings of the 2nd International Conference on Electronic & Mechanical Engineering and Information Technology (EMEIT 2012)
PB  - Atlantis Press
SP  - 1465
EP  - 1470
SN  - 1951-6851
UR  - https://doi.org/10.2991/emeit.2012.324
DO  - 10.2991/emeit.2012.324
ID  - Liu2012/09
ER  -