Journal
MATERIALS CHARACTERIZATION
Volume 71, Issue -, Pages 95-102Publisher
ELSEVIER SCIENCE INC
DOI: 10.1016/j.matchar.2012.06.011
Keywords
Al-Li based alloy; Nd:YAG laser welding; Microstructure; Microhardness; EBSD
Categories
Funding
- Aeronautical Science Foundation of China [20085475003]
- Beijing Municipal Commission of Education [00900054R5004]
Ask authors/readers for more resources
Butt joints of 3.0 mm thick sheets of an Al-Li based alloy have been produced using Nd:YAG laser welding without filler metals. The hardness distribution and microstructure of the alloy and welded joints were investigated. The changes in the grain shapes, grain orientations, microtexture, and precipitates of the fusion zone were analyzed using optical microscope, electron back scattered diffraction (EBSD) and transmission electron microscopy (TEM). The results show that Nd:YAG laser welding leads to a change of the microhardness, grain shape, grain orientations, and a disappearance of the microtexture and precipitates. A narrow band of EQZ along the fusion boundary and a predominantly equiaxed dendritic structure are developed in the fusion zone. The formation of the predominately equiaxed dendritic grains is due to a heterogeneous nucleation mechanism aided by equilibrium A1(3)Zr phases as well as the growth of pre-existing nuclei created by dendrite fragmentation, or by grain detachment resulted from Nd:YAG laser welding processes. In addition, Nd:YAG laser welding produces lower Vickers hardness than that of the base metal due to the decrease in the in quantity of delta' precipitates in the fusion zone. (C) 2012 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available