Hydroforming of lightweight materials at elevated temperature is a relatively new process with promises of increased formability at low internal pressure levels. In this study, the mechanism of warm hydroforming processes is presented in terms of its formability by comparison with warm forming, and cold hydroforming processes. Additionally, a strategy is proposed to control process parameters, such as temperature, hydraulic pressure, blank holder force, and forming speed. As a part of this strategy, the proper temperature condition is determined by adaptive-isothermal finite element analysis (FEA) and a design of experiment (DOE) approach. The adaptive-isothermal FEA determines the temperature levels of the blank material, which is selectively heated, by checking position of the blank material and adopting temperature level of the neighboring tooling. The proposed adaptive-isothermal FEA/DOE approach leads to the optimal temperature condition in a warm hydroforming system accurately and rapidly as opposed to costly and lengthy experimental trial and errors and/or fully coupled thermo-mechanical simulations. Other process parameters are also optimized in a continued study (Choi et al., 2007, “Determination of Optimal Loading Profiles in Warm Hydroforming of Lightweight Materials,” J. Mater. Process. Techn., 190(1–3), pp. 230–242.).

1.
Schultz
,
R. A.
, 1999, “
Aluminum for Light Vehicles—An Objective Look at the Next Ten to Twenty Years
14th International Aluminum Conference
,
Montreal, Canada
, Ducker Research, Sept. 15.
2.
Carpenter
,
J. A.
, 2004, “
The Freedomcar Challenge and Steel
,”
American Iron and Steel Institute
, Great Designs in Steel Seminar, Livonia MI, Feb., pp.
96
111
.
3.
Mildenberger
,
U.
, and
Khare
,
A.
, 2000, “
Planning for an Environment-Friendly Car
,”
Technovation
0166-4972,
20
, pp.
205
214
.
4.
Groche
,
P.
, 2002, “
Hydromechanical Deep-Drawing of Aluminum-Alloys at Elevated Temperature
,”
CIRP Ann.
0007-8506,
51
(
1
), pp.
215
218
.
5.
Groche
,
P.
, and
Dörr
,
J.
, 2004, personal communications, Darmstadt University.
6.
Siegert
,
K.
, 2003, “
Pneumatic Bulging of Magnesium Az31 Sheet Metals at Elevated Temperatures
,”
CIRP Ann.
0007-8506,
52
(
1
), pp.
241
244
.
7.
Siegert
,
K.
, and
Jäger
,
S.
, 2004, “
Warm Forming of Magnesium Sheet Metal
,”
SAE 2004 World Congress & Exhibition
,
Detroit, MI
, Mar., Paper No. 2004-01-1043.
8.
Novotny
,
S.
, 2003, “
Process Design for Hydroforming of Lightweight Metal Sheets at Elevated Temperatures
,”
J. Mater. Process. Technol.
0924-0136,
138
, pp.
594
599
.
9.
Li
,
D.
, and
Ghosh
,
A.
, 2003, “
Tensile Deformation Behavior of Aluminum Alloys at Warm Forming Temperatures
,”
Mater. Sci. Eng., A
0921-5093,
352
(
1–2
), pp.
279
286
.
10.
Choi
,
H.
,
Koc
,
M.
, and
Ni
,
J.
, 2007, “
Determination of Optimal Loading Profiles in Warm Hydroforming of Lightweight Materials
,”
J. Mater. Process. Technol.
0924-0136,
190
(
1–3
), pp.
230
242
.
11.
Kim
,
H. S.
,
Koc
,
M.
, and
Ni
,
J.
, 2004, “
Determination of Proper Temperature Distribution for Warm Forming of Aluminum Sheet Materials
,”
ASME J. Manuf. Sci. Eng.
1087-1357,
128
(
3
), pp.
622
633
.
12.
van den Boogaard
,
A. H.
, and
Huetink
,
J.
, 2006, “
Simulation of Aluminum Sheet Forming at Elevated Temperatures
,”
Comput. Methods Appl. Mech. Eng.
0045-7825,
195
(
48–49
), pp.
6691
6709
.
13.
Takata
,
K.
,
Ohwue
,
T.
,
Saga
,
M.
, and
Kikuchi
,
M.
, 2006, “
Formability of Al–Mg Alloy at Warm Temperature
,”
Mater. Sci. Forum
0255-5476,
331–337
, pp.
631
636
.
14.
Abedrabbo
,
N.
,
Pourboghrat
,
F.
, and
Carsley
,
J.
, 2006, “
Forming of Aluminum Alloys at Elevated Temperature—Part 2: Numerical Modeling and Experimental Verification
,”
Int. J. Plast.
0749-6419,
22
(
2
), pp.
342
373
.
15.
Kim
,
H. S.
,
Koc
,
M.
, and
Ni
,
J.
, 2006, “
Finite Element Modeling and Analysis of Warm Forming of Aluminum Alloys—Validation Through Comparison With Experiments and Determination of a Failure Criterion
,”
ASME J. Manuf. Sci. Eng.
1087-1357,
128
(
3
), pp.
613
621
.
16.
ABAQUS user manual, Hks.
17.
Dröeder
,
K. G.
, 1999, “
Untersuchungen Zum Umformen Von Veinblenchen Aus Magnesiumknetlegiereungen
,” Ph.D. thesis, University of Hannover.
18.
Jäger
,
S.
, 2004, personal communications, Stuttgart University.
19.
Choi
,
H.
,
Koc
,
M.
, and
Ni
,
J.
, 2007, “
A Study on the Analytic Modeling for Warm Hydro-Mechanical Deep Drawing of Lightweight Materials
,”
Int. J. Mach. Tools Manuf.
0890-6955,
47
(
11
), pp.
1752
1766
.
20.
Takuda
,
H.
, 2002, “
Finite Element Simulation of Deep Drawing of Aluminum Alloy Sheet With Accounting for Heat Conduction
,”
J. Mater. Process. Technol.
0924-0136,
120
, pp.
412
418
.
21.
Montgomery
,
D. C.
,
Design and Analysis of Experiments
,
5th ed.
,
Wiley
,
New York
.
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