Determination of material parameters for 7475 Al alloy from bulge forming tests at constant stress

Aoura, Youssef; Ollivier, David; Ambari, Abdelhak; Santo, Philippe Dal

doi:10.1016/j.jmatprotec.2003.09.002

Cited by 26 publications

(10 citation statements)

References 16 publications

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“…The warm bulge test provides a suitable method for material characterisation with regard to the cavity forming process without the need to resort to the uniaxial tensile test required. Concerning this matter, a few papers worth mentioning referring especially to the pole height or constant forming pressure are [6,7,8,9]. The presented pneumatic warm bulge test provides through its inprocess monitoring the development of strains ε and curvature ρ in the area of the bulge pole during the forming process.…”

Section: Materials Characterisationmentioning

confidence: 99%

See 1 more Smart Citation

Superplastic Sheet Metal Forming with Focus on the Warm Bulge Test and its In-Process Monitoring

Kappes¹,

Wagner²,

Schatz³

2010

Int J Mater Form

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Material characterisation is of prime importance in understanding its response to forming loads, which in turn influence the product design. The flow stress in plastic loading defines the evolution of the yield surface and depends on a variety of factors such as strain, strain rate and temperature. The degree of influence of the strain rate increases at higher temperatures. This effect can be well described with superplastic forming, in which the material is loaded very slowly at superplastic temperatures. This paper deals with monitoring of process parameters during superplastic sheet metal forming of magnesium alloys, with special emphasis on in-process measurements for bulge test purposes at elevated temperatures. The strain evolution near the part"s pole region has been recorded in-process by using the ViALUX photogrammetric strain analysis system AutoGrid. The recorded data provides a lot of information about the forming process such as evolution of strains, strain rate, flow stress and the limit strains, which allows determining all relevant material and process parameters for superplastic forming.

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Section: Materials Characterisationmentioning

confidence: 99%

“…[10,11,12] Generally, the mechanical behaviour of superplastic materials at constant temperatures is described by an enhancement of the approximation according to Ludwik [1,7,13]:…”

Section: Materials Characterisationmentioning

confidence: 99%

Superplastic Sheet Metal Forming with Focus on the Warm Bulge Test and its In-Process Monitoring

Kappes¹,

Wagner²,

Schatz³

2010

Int J Mater Form

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“…1, process time, T, forming pressure, P, and critical thickness, S n, for a spherical component are found as follows [38,42]:…”

Section: Appendixmentioning

confidence: 99%

Experiments with a Low-Cost Hot Isothermal Pressing Machine Developed for Superplastic Forming

Nategh

Jafari

2008

J. of Materi Eng and Perform

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Hot isothermal/isostatic pressing machines are technically good candidates for superplastic forming (SPF) of otherwise hard-to-shape materials such as superalloys. These machines are, however, very expensive so that small or medium-size enterprises can not afford them. This has impeded widespread use of SPF processing. In an attempt to alleviate the problem, the authors have developed a laboratory model of an affordable hot isothermal pressing machine with differential gas pressure as the forming medium. Careful selection of process parameters such as temperature, gas pressure, strain rate, and process time as well as monitoring of thickness changes in a workpiece has a pivotal role in successful operation of such machine. It has been illustrated in this article that SPF can be successfully performed with this machine on the basis of process parameters estimated with existing analytical relations. The performance of this machine has been verified by several experiments on SPF of titanium-based sheets, as reported in this article.

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“…The forming of the part is performed at high temperature (350°C), which corresponds to the solution treatment temperature of the alloy. An instrumented bulging demonstrator developed by the LAMPA is used [3]. As shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

Creep forming of an Al-Mg-Li alloy for aeronautic application

Younes¹,

Giraud²,

Fredj³

et al. 2016

AIP Conference Proceedings

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Creep forming of Al-Mg-Li alloy sheets is studied. An instrumented bulging machine is used to form a double curvature panel at a reduced scale. The deformation of the worksheet is ensured by a 7475 aluminum alloy lost sheet deformed by a gas pressure applied on its upper surface. A numerical model using the ABAQUS software is developed in order to obtain the pressure law and to ensure the forming conditions during the cycle. This model is validated by comparing experiments and numerical results in terms of deformed shape and thickness evolution.

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Determination of material parameters for 7475 Al alloy from bulge forming tests at constant stress

Cited by 26 publications

References 16 publications

Superplastic Sheet Metal Forming with Focus on the Warm Bulge Test and its In-Process Monitoring

Superplastic Sheet Metal Forming with Focus on the Warm Bulge Test and its In-Process Monitoring

Experiments with a Low-Cost Hot Isothermal Pressing Machine Developed for Superplastic Forming

Creep forming of an Al-Mg-Li alloy for aeronautic application

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