Hot deformation behaviour of 7075 alloy

Rajamuthamilselvan, M.; Ramanathan, S.

doi:10.1016/j.jallcom.2010.09.139

Cited by 127 publications

(43 citation statements)

References 25 publications

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“…High strain rate deformation processes are essentially adiabatic. Thus, the temperature of the sample can rise during deformation, which decreases the flow stress of the material and leads to thermal softening [7,15,16,22,26]. Fig.…”

Section: Flow Stress Curvesmentioning

confidence: 99%

“…Processing parameters, such as the deformation temperature and strain rate, and material factors, such as chemical composition and microstructure of the starting material, are the main factors affecting the hot deformation flow stress. Thus, several studies have been performed to investigate the effect of processing parameters on the hot deformation behaviour of aluminium and its alloys [3,6,[14][15][16]. Furthermore, the flow stress behaviour of these materials has been modelled, and constitutive equations that consider the effects of the deformation temperature and strain rate have been proposed to predict the hot deformation flow stress [13,17,18].…”

Section: Introductionmentioning

confidence: 99%

“…The hot deformation behaviour of bulk aluminium alloys has been the subject of many studies [3,6,7,[14][15][16][19][20][21]. Nevertheless, the deformation behaviour of porous materials is different which leads to after-consolidation mechanical properties that cannot be attained through the conventional processing of cast and wrought alloys with similar chemical compositions [8].…”

Section: Introductionmentioning

confidence: 99%

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Hot deformation behaviour and flow stress prediction of 7075 aluminium alloy powder compacts during compression at elevated temperatures

Taleghani

Ruiz-Navas

Salehi

et al. 2012

Materials Science and Engineering: A

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Abstract:In the present study, the hot deformation behaviour of 7075 aluminium alloy powder compacts was studied by performing hot compression tests on a Gleeble 3800 machine. The main objectives were to evaluate the effect of the relative green density on the hot deformation behaviour and to model and predict the hot deformation flow stress of powder compacts using constitutive equations. For this pur-pose, powder compacts with relative green densities ranging from 83 to 95%, which were prepared by uniaxial cold pressing a commercial pre-mixed powder, were hot compressed at temperatures ranging from 350 • Cto450 • C and at true strain rates ranging from 0.01 s −1 to 10 s −1 . The true stress-true strain curves of the powder compacts exhibited a peak stress at a critical strain after which the flow stress remained nearly constant. As the deformation temperature increased or the strain rate and green density decreased, a decrease in the peak stress level was observed. The relationship between deformation tem-perature, strain rate, and the peak flow stress of powder compacts was described by the Zener-Hollomon parameter in an exponential equation containing relative green density compensated material constants and the deformation activation energy. The peak flow stresses calculated from the proposed formula were in good agreement with the experimental results, which confirms the applicability of the employed method for the prediction of the hot deformation flow stress of porous materials with different relative green densities.

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Section: Flow Stress Curvesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Hot deformation behaviour and flow stress prediction of 7075 aluminium alloy powder compacts during compression at elevated temperatures

Taleghani

Ruiz-Navas

Salehi

et al. 2012

Materials Science and Engineering: A

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“…The processing maps were developed on the basis of dynamic material model (DMM) and had been used to design hot working schedules in a wide variety of materials [13][14][15]. The maps explicitly represented local peak efficiency of power dissipation, which was the response of specific microstructure mechanism and regions of flow instability.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Hot Deformation Behavior of a Novel Al–Cu–Li Alloy Using Processing Maps

Yiran

Yin

et al. 2015

Acta Metall. Sin. (Engl. Lett.)

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The isothermally compression deformation behavior of an elevated Cu/Li weight ratio Al-Cu-Li alloy was investigated under various deformation conditions. The isothermal compression tests were carried out in a temperature range from 300 to 500°C and at a strain rate range from 0.001 to 10 s -1 . The results show that the peak stress level decreases with temperature increasing and strain rate decreasing, which is represented by the Zener-Hollomon parameter Z in the hyperbolic sine equation with the hot deformation activation energy of 218.5 kJ/mol. At low Z value, the dynamic recrystallized grain is well formed with clean high-angle boundaries. At high Z value, a high dislocation density with poorly developed cellularity and considerable fine dynamic precipitates are observed. Based on the experimental data and dynamic material model, the processing maps at strain of 0.3, 0.5 and 0.7 were developed to demonstrate the hot workability of the alloy. The results show that the main softening mechanism at high Z value is precipitate coarsening and dynamic recovery; the dynamic recrystallization of the alloy can be easily observed as ln Z B 29.44, with peak efficiency of power dissipation of around 70%. At strains of 0.3, 0.5 and 0.7, the flow instability domains are found at higher strain rates, which mainly locate at the upper part of processing maps. In addition, when the strain rate is 0.001 or 0.02 s -1 , there is a particular instability domain at 300-350°C.

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“…Aluminum alloys find potential application in automobile and aerospace industries [1][2][3] for their high strength to weight ratio. The microstructure and properties of them can be strongly affected by adding small amounts of transition elements such as Zr, Mn and Cr, etc.…”

Section: Introductionmentioning

confidence: 99%