Numerical Modeling of Microstructure of Heat Affected Zone in Friction Stir Welded AA7075

Volume 1, Issue 1, October 2016     |     PP. 20-30      |     PDF (651 K)    |     Pub. Date: October 17, 2016
DOI:    490 Downloads     7700 Views  

Author(s)

A. Abdollah-zadeh, Tarbiat Modares University, Department of Materials Engineering, P.O. Box: 14115-143, Tehran, Iran
A. Mehri, Tarbiat Modares University, Department of Materials Engineering, P.O. Box: 14115-143, Tehran, Iran
S. Entesari, Tarbiat Modares University, Department of Materials Engineering, P.O. Box: 14115-143, Tehran, Iran
H. Assadi, Tarbiat Modares University, Department of Materials Engineering, P.O. Box: 14115-143, Tehran, Iran

Abstract
There is interest in the study and control of heat affected zone (HAZ) of the weld junctions, which is often regarded as the weakest point of the joints. In the present work, experimental and numerical analyses are used to characterize extension and microstructure of HAZ in friction stir welding (FSW) of 7075 Al alloy (AA) sheets. The thermal history was recorded by inserting thermocouples near the HAZ. These measurements were combined with a numerical modeling to predict thermal histories of various welding conditions. Moreover, the grain growth behavior of the base metal, including the growth kinetic constant, was determined through a series of isothermal annealing at different temperatures followed by grain size measurements. In this way, the grain structure of the HAZ could be linked to the welding conditions. A good agreement between the predicted and observed values was obtained over a wide range of conditions.

Keywords
AA7075; HAZ; Numerical modeling; Thermal cycle, FSW

Cite this paper
A. Abdollah-zadeh, A. Mehri, S. Entesari, H. Assadi, Numerical Modeling of Microstructure of Heat Affected Zone in Friction Stir Welded AA7075 , SCIREA Journal of Materials. Volume 1, Issue 1, October 2016 | PP. 20-30.

References

[ 1 ] R. S. Mishra, M. W. Mahoney, "Friction stir welding and processing", ASM International, Ohio, 2007, p.3.
[ 2 ] G. Matters,"The welding of aluminum and its alloys", CRC press, North America, 2002, p. 13.
[ 3 ] H. Jamshidi Aval, S. Serajzadeh, A.H. Kokabi, "Prediction of grain growth behavior in HAZ during gas tungsten arc welding of 304 stainless steel", Materials Engineering and Performance, Vol. 18, 2009, pp. 1193–1200.
[ 4 ] M. Shome, "Effect of heat-input on austenite grain size in the heat-affected zone of HSLA-100 steel", Materials Science and Engineering A, 2007, Vol. 445–446, pp. 454–460.
[ 5 ] R. E. Reed-Hill, "Physical Metallurgy Principles", D Van Nostrand Company pulications, North America,1973, pp. 298-309.
[ 6 ] M. Shome , O.P. Gupta, O.N. Mohanty, "A modified analytical approach for modelling grain growth in the coarse grain HAZ of HSLA steels", Scripta Materialia, 2004, Vol. 50, pp. 1007–1010.
[ 7 ] H. Ikawa, S. Shin, H. Oshige, "Grain growth of commercial-purity nickel in welh-heat affected zone", Japan welding society, 1975, Vol. 6, pp.17-22.
[ 8 ] P. Feltham, G. J. Copley, "Grain growth in a-brasses", Acta Metallurgica, 1958, Vol. 6, pp. 539-543.