Modelling approach for predicting the superplastic deformation behaviour of titanium alloys with strain hardening/softening characterizations

Mosleh, Ahmed O.; Mestre-Rinn, P.; Khalil, A.; Котов, А. Д.; Mikhaylovskaya, A. V.

doi:10.1088/2053-1591/ab59b5

Cited by 16 publications

(6 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Assuming m < 1, stable plastic deformation is viable only when the strain-hardening rate ( θ ) is positive. Nevertheless, the superplastic behaviour has been frequently reported even when strain softening occurs [41]. A more general criterion for deformation stability was proposed by Haehner et al [42], which incorporates the effect of microstructural evolution.…”

Section: Resultsmentioning

confidence: 99%

Microstructure, texture, and instability during superplastic deformation of ECAP-treated AZ31 Mg alloy

Fatemi-Varzaneh

Paul

Hemmati-Hosuri

2023

Materials Science and Technology

View full text Add to dashboard Cite

An ultrafine-grained AZ31 Mg alloy processed through multipass equal channel angular pressing (ECAP) achieved 5 and 0.9 µm mean grain sizes after two and four passes, respectively. The deformation behaviour of the alloy was studied through tensile testing at high temperatures. A 410% superplastic elongation was achieved at 250°C during the tensile deformation of the four-pass-processed alloy. The Haehner criterion allowed the prediction of the stable uniform deformation of the alloy. The strain rate sensitivity of 0.38 and equiaxed microstructure suggested grain boundary sliding as the rate-controlling mechanism. The slip system's contribution to superplasticity was discussed using related Schmid factors. Slip activity prevalence at high strains induced a texture-strengthening effect and allowed low-angle grain boundary formation at high strains.

show abstract

Section: Resultsmentioning

confidence: 99%

Microstructure, texture, and instability during superplastic deformation of ECAP-treated AZ31 Mg alloy

Fatemi-Varzaneh

Paul

Hemmati-Hosuri

2023

Materials Science and Technology

View full text Add to dashboard Cite

show abstract

“…The closer

is to 1, the smaller RMS is, which indicates that the model is more accurate in predicting experimental data. In order to verify the accuracy of the model, the independent data are added, which are not used to build the model under other conditions [ 34 ]. A set of data are strain rate of 1 s −1 and temperatures of 1125 °C, 1175 °C, 1225 °C, respectively.…”

Section: Experimental Results Analysis Of X12 Ferritic Heat-resistant Steelmentioning

confidence: 99%

Identification of the Constitutive Model Parameters by Inverse Optimization Method and Characterization of Hot Deformation Behavior for Ultra-Supercritical Rotor Steel

Chen

et al. 2021

Materials

View full text Add to dashboard Cite

X12 (X12CrMoWVNbN10-1-1) ferritic heat resistant steel is an important material for the production of new-generation ultra-supercritical generator rotors. Hot compression tests of X12 ferritic heat-resistant steel were performed via a Gleeble-1500D testing machine under temperatures of 1050–1250 °C and strain rates of 0.05–5 s−1. In order to provide material model data for finite element simulations and accurately predict the hot deformation behavior, a reverse optimization method was proposed to construct elevated temperature constitutive models of X12 ferritic heat-resistant steel in this paper, according to the Hansel–Spittel constitutive model. To verify the accuracy of the model, the predicted and experimental values of the constitutive model were compared. The results indicated that the model had a high prediction accuracy. Meanwhile, the correlation coefficient between the experimental value and the predicted value of constitutive model was 0.97833. For further verification of the accuracy of the model, it was implemented in finite element FORGE@ software to simulate the compression tests of different samples under different conditions. Comparing actual displacement–load curves with displacement–load curves acquired through finite element simulations, the results indicated that displacement–load curves predicted by the model were very consistent with actual displacement–load curves, which verified the accuracy of the model. Moreover, to research the optimal processing parameters of the material, hot processing maps were drawn according to the dynamic material model. In terms of microstructure evolution, a characteristic area distribution map of the hot processing map was established. Therefore, the optimal hot forming parameters regions were in the range of 1150–1200 °C/0.05–0.62 s−1 for X12 ferritic heat-resistant steel.

show abstract

“…The WH and DRV processes were modeled in early research [29,30], and the dislocation density was introduced as the main ISV in the Kocks-Meching (K-M) model. With the development of physical-based ISV models, some other complicated deformation mechanisms were also considered, such as DRX [14,[31][32][33], spheroidization [15,34,35] and precipitation [11], which can greatly influence the flow stress. Recently, many investigations have been made to introduce these physical mechanisms into constitutive models.…”

Section: Introductionmentioning

confidence: 99%

Microstructure Evolution and a Unified Constitutive Model of Ti-55511 Alloy Compressed at Stepped Strain Rates

Zhong

Lin

et al. 2021

Materials

View full text Add to dashboard Cite

The flow behavior and microstructure change of the Ti-55511 alloy are investigated by thermal compression experiments with stepped strain rates. The phase transformation features, the dynamic recrystallization (DRX) behavior of the β matrix, the dynamic spheroidization mechanism of the lamellar α phase and the evolution of the β sub-grain size are quantitatively analyzed. A unified constitutive model is constructed to characterize the hot deformation features of the Ti-55511 alloy. In the established model, the work hardening effect is taken into account by involving the coupled effects of the equiaxed and lamellar α phases, as well as β substructures. The dynamic softening mechanisms including the dynamic recovery (DRV), DRX and dynamic spheroidization mechanisms are also considered. The material parameters are optimized by the multi-objective algorithm in the MATLAB toolbox. The consistency between the predicted and experimental data indicates that the developed unified model can accurately describe the flow features and microstructure evolution of the hot compressed Ti-55511 at stepped strain rates.

show abstract

Modelling approach for predicting the superplastic deformation behaviour of titanium alloys with strain hardening/softening characterizations

Cited by 16 publications

References 44 publications

Microstructure, texture, and instability during superplastic deformation of ECAP-treated AZ31 Mg alloy

Microstructure, texture, and instability during superplastic deformation of ECAP-treated AZ31 Mg alloy

Identification of the Constitutive Model Parameters by Inverse Optimization Method and Characterization of Hot Deformation Behavior for Ultra-Supercritical Rotor Steel

Microstructure Evolution and a Unified Constitutive Model of Ti-55511 Alloy Compressed at Stepped Strain Rates

Contact Info

Product

Resources

About