In this paper, the metallurgical phenomena occurring in friction stir welding processes of AA6082-T6 and AA7075-T6 aluminum alloys are investigated. In particular, to predict the local values of the average grain size, either a simple analytical expression depending on a few material constants or a properly trained neural network is linked to the finite element model of the process. The utilized tools, which take as inputs the local values of strain, strain rate, and temperature, were developed starting from experimental data and numerical results.

1.
Liu
,
H. J.
,
Fujii
,
H.
,
Maeda
,
M.
, and
Nogi
,
K.
, 2003, “
Tensile Properties and Fracture Locations of Friction-Stir-Welded Joints of 2017-T351 Aluminum Alloy
,”
J. Mater. Process. Technol.
0924-0136,
142
, pp.
692
696
.
2.
Rhodes
,
C. G.
,
Mahoney
,
M. W.
,
Bingel
,
W. H.
,
Spurling
,
R. A.
, and
Bampton
,
C. C.
, 1997, “
Effects of Friction Stir Welding on Microstructure of 7075 Aluminum
,”
Scr. Mater.
1359-6462,
36
(
1
), pp.
69
75
.
3.
Guerra
,
M.
,
Schmidt
,
C.
,
McClure
,
L. C.
,
Murr
,
L. E.
, and
Nunes
,
A. C.
, 2003, “
Flow Patterns During Friction Stir Welding
,”
Mater. Charact.
1044-5803,
49
, pp.
95
101
.
4.
Shigematsu
,
I.
,
Kwon
,
Y. J.
,
Suzuki
,
K.
,
Imai
,
T.
, and
Saito
,
N.
, 2003, “
Joining of 5083 and 6061 Aluminum Alloys by Friction Stir Welding
,”
J. Mater. Sci. Lett.
0261-8028,
22
, pp.
343
356
.
5.
Lee
,
W. B.
,
Yeon
,
Y. M.
, and
Jung
,
S. B.
, 2003, “
The Improvement of Mechanical Properties of Friction-Stir-Welded A356 Al Alloy
,”
Mater. Sci. Eng., A
0921-5093,
355
, pp.
154
159
.
6.
Liu
,
G.
,
Murr
,
L. E.
,
Niou
,
C. S.
,
McClure
,
J. C.
, and
Vega
,
F. R.
, 1997, “
Micro-structural Aspects of the Friction-Stir Welding of 6061-T6 Aluminum Alloy
,”
Scr. Mater.
1359-6462,
37
, pp.
355
361
.
7.
Song
,
M.
, and
Kovacevic
,
R.
, 2003, “
Thermal Modeling of Friction Stir Welding in a Moving Coordinate System and Its Validation
,”
Int. J. Mach. Tools Manuf.
0890-6955,
43
, pp.
605
615
.
8.
Schmidt
,
H.
,
Hattel
,
J.
, and
Wert
,
J.
, 2004, “
An Analytical Model for the Heat Generation in Friction Stir Welding
,”
Modell. Simul. Mater. Sci. Eng.
0965-0393,
12
, pp.
143
157
.
9.
Chao
,
Y. J.
,
Qi
,
X.
, and
Tang
,
W.
, 2003, “
Heat Transfer in Friction Stir Welding—Experimental and Numerical Studies
,”
ASME J. Manuf. Sci. Eng.
1087-1357,
125
, pp.
138
145
.
10.
Chen
,
C. M.
, and
Kovacevic
,
R.
, 2003, “
Finite Element Modeling of Friction Stir Welding—Thermal and Thermomechanical Analysis
,”
Int. J. Mach. Tools Manuf.
0890-6955,
43
, pp.
1319
1326
.
11.
Lockwood
,
W. D.
, and
Reynolds
,
A. P.
, 2003, “
Simulation of the Global Response of a Friction Stir Weld Using Local Constitutive Behavior
,”
Mater. Sci. Eng., A
0921-5093,
339
, pp.
35
42
.
12.
Xu
,
S.
, and
Deng
,
X.
, 2003, “
Two and Three Dimensional Finite Element Models for the Friction Stir Welding Process”
,”
Proceedings of the Fourth International Symposium on Friction Stir Welding
,
Park City
.
13.
Xu
,
S.
, and
Deng
,
X.
, 2002, “
A Three-Dimensional Model for the Friction-Stir Welding Process
,”
Proceedings of the 21th Southestern Conference on Theoretical and Applied Mechanics
,
Orlando, FL
.
14.
Deng
,
X.
, and
Xu
,
S.
, 2001, “
Solid Mechanics Simulation of Friction Stir Welding Process
,”
Trans. NAMRI/SME
1047-3025,
29
, pp.
631
638
.
15.
Buffa
,
G.
, and
Fratini
,
L.
, 2004, “
Friction Stir Welding of AA6082-T6 Sheets: Numerical Analysis and Experimental Tests
,”
Proceedings of Eighth NUMIFORM Conference
,
Columbus
, pp.
1224
1229
.
16.
Buffa
,
G.
, and
Fratini
,
L.
, 2005, “
CDRX Modeling in Friction Stir Welding of Aluminum Alloys
,”
Int. J. Mach. Tools Manuf.
0890-6955,
45
(
10
), pp.
1188
1194
.
17.
Buffa
,
G.
, and
Fratini
,
L.
, 2005, “
Numerical Modeling of Friction Stir Welding: A Grain Size Evolution Model
,”
Proceedings of Eighth ICTP Conference
.
18.
Jata
,
K. V.
, and
Semiatin
,
S. L.
, 2000, “
Continuous Dynamic Recrystallization During Friction Stir Welding of High Strength Aluminum Alloys
,”
Scr. Mater.
1359-6462,
43
, pp.
743
749
.
19.
Su
,
J. Q.
,
Nelson
,
T. W.
,
Mishra
,
R.
, and
Mahoney
,
M.
, 2003, “
Microstructural Investigation of Friction Stir Welded 7050-T654 Aluminium
,”
Acta Mater.
1359-6454,
51
, pp.
713
729
.
20.
1993,
ASM Speciality Handbook: Aluminum and Aluminum Alloys
,
J. R.
Davis
, ed.,
ASM International
,
Metals Park
,
OH
.
21.
Barcellona
,
A.
,
Buffa
,
G.
, and
Fratini
,
L.
, 2004, “
Process Parameters Analysis in Friction Stir Welding of AA6082-T6 Sheets
,”
Keynote Paper of the VII ESAFORM Conference
,
Trondhaim
, pp.
371
374
.
22.
2004, DEFORM 3D V5.0, User’s Manual, SFC, Columbus, OH.
23.
Fratini
,
L.
,
Beccari
,
S.
, and
Buffa
,
G.
, 2005, “
Friction Stir Welding FEM Model Improvement Through Inverse Thermal Characterization
,”
Trans. NAMRI/SME
1047-3025,
33
, pp.
259
266
.
24.
Buffa
,
G.
,
Hua
,
J.
,
Shivpuri
,
R.
, and
Fratini
,
L.
, 2006, “
A Continuum Based FEM Model for Friction Stir Welding—Model Development
,”
Mater. Sci. Eng., A
0921-5093,
419
(
1–2
), pp.
381
388
.
25.
Lenard
,
J. G.
,
Pietrzyk
,
M.
, and
Cser
,
L.
, 1999,
Mathematical and Physical Simulation of the Properties of Hot Rolled Products
,
Elsevier
,
New York
.
26.
Vandermeer
,
R. A.
, and
Juul Jensen
,
D.
, 2001, “
Microstructural Path and Temperature Dependence of Recrystallization in Commercial Aluminum
,”
Acta Mater.
1359-6454,
49
, pp.
2083
2094
.
27.
McQueen
,
H. J.
, and
Ryan
,
N. D.
, 2002, “
Constitutive Analysis in Hot Working
,”
Mater. Sci. Eng., A
0921-5093,
322
, pp.
43
63
.
28.
Fu
,
L.
, 1994,
Neural Networks in Computer Intelligence
,
McGraw-Hill
,
New York
.
29.
Fratini
,
L.
, and
Lo Nigro
,
G.
, 1995, “
Neural Network Application in Laser Bending Process: Direct and Inverse Approaches
,”
Proceedings of II AITEM Conference
, pp.
11
20
.
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