The press formability of the automotive materials such as aluminum alloys, magnesium alloys and steels is influenced by forming temperatures. While adjusting the temperature level of die, punch and binder, the lightweight materials can successfully be formed, especially for complex automotive body parts. The objective of this case study is to determine the forming limit curves of Al6014 and DP600 alloy sheet at elevated temperatures in specific range of 200 °C and 250 °C suitable for press operation in long-run production cycles. The focus is set on Al6014 and DP600 as these two materials are widely used in automotive panels due to their high strength and lightweight and improved resistance to corrosion. DP600 is sometimes preheated before forming to avoid cracks. Thus, it is essential to study the effect of preheating temperature on the formability. Experiments were conducted at forming temperatures of 200 °C and 250 °C and at low punch speed. The measurement of train distribution was carried out online using digital image correlation with the optical deformation measurement system GOM Aramis. Both Al6014 and DP600 alloys were found to have good drawability and stretchability. It was found that for Al6014, the forming limit curve level increases with temperature. On the contrary, DP600 showed slight decrease in the level of forming limit curve as temperature was increased. Warm formability for these alloys was further characterized through part depth and percentage thinning measurements.
FinchDMWilsonSPDornJE. Deep drawing aluminium alloys at elevated temperatures, part I: deep drawing cylindrical cups. Trans ASM1946; 36: 254–289.
2.
FukuiS. Deep drawing at elevated temperatures. Rep Inst Phys Chem Res1948; 24: 209–211.
3.
ShehataFPainterMJPearceR. Warm forming of aluminium/magnesium alloy sheet. J Mech Work Technol1978; 2: 279–290.
4.
MukhopadhyayJ. Deformation behaviour of Al-Mg alloys. PhD Thesis, Indian Institute of Technology Bombay, Mumbai, India, 1982.
5.
MukhopadhyayJMukherjeeAKMallikAK. Correlation of uniaxial data with forming limit curves of Al-Mg alloy deformed at ambient and high temperatures. J Mater Sci1990; 25: 977–982.
6.
NakaTYoshidaF. Deep drawability of type 5083 aluminium–magnesium alloy sheet under various conditions of temperature and forming speed. J Mater Process Tech1999; 90: 19–23.
7.
NakaTTorikaiGHinoR. The effects of temperature and forming speed on the forming limit diagram for type 5083 aluminum-magnesium alloy sheet. J Mater Process Tech2001; 113(1–3): 648–653.
8.
TakudaHMoriKMasudaI. Finite element simulation of warm deep drawing of aluminium alloy sheet when accounting for heat conduction. J Mater Process Tech2002; 120: 412–418.
9.
LiDGhoshAK. Biaxial warm forming behavior of aluminum sheet alloys. J Mater Process Tech2004; 145(3): 281–293.
10.
SpigarelliSCiccarelliDEvangelistaE. Compressive deformation of an Mg-Al-Si-RE alloy between 120 and 180 °C. Mater Lett2004; 58(3–4): 460–464.
11.
KimHSKoçMNiJ. Finite element modeling and analysis of warm forming of aluminum alloys—validation through comparisons with experiments and determination of a failure criterion. J Manuf Sci Eng2006; 128(3): 613–621.
12.
AbedrabboNPourboghratFCarsleyJ. Forming of aluminum alloys at elevated temperatures—part 2: numerical modeling and experimental verification. Int J Plasticity2006; 22(2): 342–373.
13.
Van Den BoogaardAHHuetinkJ. Modelling of aluminium sheet material at elevated temperatures. Mater Process Des Model Simul Appl2004; 712(2): 893–898.
14.
SaxenaKKMukhopadhyayJRameshKV. Formability characterization of aluminium lithium alloys used in spacecraft industry. In: Proceedings of the international mechanical engineering congress and exposition, IMECE 2014, Montreal, QC, Canada, 14–20 November 2014, p.V02AT02A026. New York: ASME.
15.
ChuXLeotoingLGuinesD. Temperature and strain rate influence on AA5086 forming limit curves: experimental results and discussion on the validity of the M-K model. Int J Mech Sci2014; 78: 27–34.
16.
Van Den BoogaardAHHuétinkJ. Simulation of aluminium sheet forming at elevated temperatures. Comput Method Appl M2006; 195(48–49): 6691–6709.
17.
ChoiHKoçMNiJ. A study on the analytical modeling for warm hydro-mechanical deep drawing of lightweight materials. Int J Mach Tool Manu2007; 47(11): 1752–1766.
18.
PalumboGTricaricoL. Numerical and experimental investigations on the warm deep drawing process of circular aluminum alloy specimens. J Mater Process Tech2007; 184(1–3): 115–123.
19.
TorosSOzturkFKacarI. Review of warm forming of aluminum–magnesium alloys. J Mater Process Tech2008; 207(1–3): 1–12.
20.
PalumboGPiccininniA. Numerical–experimental investigations on the manufacturing of an aluminium bipolar plate for proton exchange membrane fuel cells by warm hydroforming. Int J Adv Manuf Tech2013; 69(1–4): 731–742.
21.
ZhangCChuXGuinesD. Effects of temperature and strain rate on the forming limit curves of AA5086 sheet. Proced Eng2014; 81: 772–778.
22.
LaurentHCoërJManachPY. Experimental and numerical studies on the warm deep drawing of an Al–Mg alloy. Int J Mech Sci2015; 93: 59–72.
23.
JuLPatilSDykemanJ. Forming of Al 5182-O in a servo press at room and elevated temperatures. J Manuf Sci Eng2015; 137: 1–7.
24.
HashemiSJNaeiniHMLiaghatGH. Prediction of bulge height in warm hydroforming of aluminum tubes using ductile fracture criteria. Arch Civ Mech Eng2015; 15(1): 19–29.
25.
GuvenEA. An investigation on the effects of pre-deformation and temperature on thixotropic microstructure of AA2014 aluminum alloy. T Indian I Metals2016; 69(4): 935–940.
26.
CetinMHUgurAYigitO. Development of forming temperature curves for warm deep drawing process under non-isothermal conditions. Arab J Sci Eng2015; 40: 2763–2784.
27.
AfshinEKadkhodayanM. An experimental investigation into the warm deep-drawing process on laminated sheets under various grain sizes. Mater Design2015; 87: 25–35.
28.
ZhangNAbu-farhaF. Characterizing and modeling the deformation of AA5182 for hot blank cold die (HB-CD) stamping. TMS Light Met2015; 2015: 315–320.
29.
JayahariLNaikBBSinghSK. Effect of process parameters and metallographic studies of ASS-304 stainless steel at various temperatures under warm deep drawing. Proced Mater Sci2014; 6: 115–122.
30.
GoudRRPrasadKESinghSK. Formability limit diagrams of extra-deep-drawing steel at elevated temperatures. Proced Mater Sci2014; 6: 123–128.
31.
KeitaODubosPAChottinJ. Numerical prediction model of temperature effect on DP1000 steel damage during warm formability. Key Eng Mat2015; 651–653: 77–82.
32.
SenNKurganN. Improving deep drawability of HC300LA sheet metal by warm forming. Int J Adv Manuf Tech2016; 82(5): 985–995.
33.
KongTFChanLC. Prediction of multipreform shapes in warm forming with experimental verification. J Miner Met Mater Soc2015; 67(2): 436–449.
34.
ISO 6892-1:2009. Metallic materials—tensile testing, part 1: method of test at room temperature.
35.
ISO 12004-2:2008. Metallic materials—sheet and strip—determination of forming limit curves—part 2: determination of forming limit curves in the laboratory.
36.
DolzhenkovIE. The nature of blue brittleness of steel. Met Sci Heat Treat1971; 13(3): 220–224.
37.
WaterschootTDeAKVandeputteS. Static strain aging phenomena in cold-rolled dual-phase steels. Metall Mater Trans A2003; 34(13): 781–791.
38.
CaoYAhlströmJKarlssonB. The influence of temperatures and strain rates on the mechanical behavior of dual phase steel in different conditions. J Mater Res Technol2015; 4(1): 68–74.
