Investigation of tension–compression asymmetry of magnesium by use of the acoustic emission technique

Máthis, Kristián; Čapek, Jan; Zdražilová, Zuzana; Trojanová, Zuzanka

doi:10.1016/j.msea.2011.03.114

Cited by 54 publications

(38 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such robustness testies that the quantitative dierence between the materials with dierent microstructure is not due to artifacts of the AE method but reects physically sound changes in the correlation of the deformation processes (see, e.g., [11]). …”

Section: Resultsmentioning

confidence: 98%

“…It has been shown to depend on the microscopic mechanisms of plasticity, the type of loading, the specimen geometry, the deformation stage, the strain rate, and temperature (e.g., [10,11]). In spite of this diversity, the investigation performed in the present study revealed a For all samples, and similarly to other materials, high nonstationary AE activity is observed at small strains, in the region of the elastoplastic transition.…”

Section: Resultsmentioning

confidence: 99%

“…It further decreases and displays roughly stationary behavior, which allows performing the statistical analysis in a steady--state range. Figure 1 presents an example of an acoustic signal recorded during tension of a specimen of the Mg0.35%Zr alloy for which the AE is known to be essentially governed by twinning [11].…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Acoustic-Emission Study of Intermittency of Plastic Flow during Twinning and Dislocation Glide

et al. 2012

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Acoustic-Emission Study of Intermittency of Plastic Flow during Twinning and Dislocation Glide

et al. 2012

View full text Add to dashboard Cite

“…However, predicting the macroscopic mechanical response of bulk polycrystalline magnesium while also resolving the local fields, particularly interactions of twins with grain boundaries, presents an open challenge. The hexagonal closed-packed (hcp) crystal structure of Mg results in anisotropic inelastic deformation mechanisms (Graff et al, 2007;Stanford et al, 2011), remarkably low ductility and an asymmetric tension-compression behavior (Máthis et al, 2011;Park et al, 2014;Zachariah et al, 2013;Kurukuri et al, 2014). Dislocation slip and deformation twinning occur as competing mechanisms, and their mechanistic influences drive complex microstructure evolution paths observed in magnesium polycrystals (Agnew and Duygulu, 2005;Chang et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Deformation patterning in finite-strain crystal plasticity by spectral homogenization with application to magnesium

Vidyasagar

Tutcuoglu

Kochmann

2018

Computer Methods in Applied Mechanics and Engineering

View full text Add to dashboard Cite

Complex microstructural patterns arise as energy-minimizers in systems having non-convex energy landscapes such as those associated with phase transformations, deformation twinning, or finite-strain crystal plasticity. The prediction of such patterns at the microscale along with the resulting, effective material response at the macroscale is key to understanding a wide range of mechanical phenomena and has classically been dealt with by simplifying energy relaxation theory or by expensive finite element calculations. Here, we discuss a stabilized Fourier spectral technique for the homogenized response at the level of a representative volume element (RVE). We show that the FFT-based method admits sufficiently high resolution suitable to predict the emergence of energy-minimizing microstructures and the resulting effective response by computing the approximated quasiconvex energy hull. We test the method in the classical single-slip problem in single-and bicrystals. Especially the latter goes beyond the scope of traditional finite element and analytical relaxation treatments and hints at mechanisms of pattern formation in polycrystals. We also demonstrate that the chosen spectral finite-difference approximation, important for removing ringing artifacts in the presence of high contrasts, adds a natural regularization to the non-convex minimization. Finally, the technique is applied to polycrystalline pure magnesium, where we account for the competition between dislocation-mediated plasticity and deformation twinning. These inelastic deformation mechanisms result in complex texture evolution paths at the polycrystalline mesoscale and are simulated within RVEs of varying grain size and texture by a constitutive crystal plasticity model with an effective, volume fraction-based description of twinning.

show abstract

“…All of the slip systems mentioned so far provides only a total of four independent slip systems [2]; none of them can produce strain parallel to the c axis. This is possible only either in a second-order pyramidal slip system or by mechanical twinning [3]. The critical resolved shear stress (CRSS) in non-basal slip systems at lower temperatures is much higher in comparison with the CRSS for the basal slip.…”

Section: Introductionmentioning

confidence: 99%

Superplastic Behaviour of an Extruded AZ91 Alloy

et al. 2012

View full text Add to dashboard Cite

Plastic deformation of extruded AZ91 magnesium alloy was investigated at various strain rates and in a temperature range of 360420• C. Samples exhibiting superplastic behaviour were prepared with dierent thermo-mechanical treatments. Microstructure of samples was observed by light and scanning electron microscopy. The strain rate sensitivity parameter m has been estimated by the abrupt strain rate change method. Possible physical mechanisms of the superplastic ow are discussed.

show abstract

Investigation of tension–compression asymmetry of magnesium by use of the acoustic emission technique

Cited by 54 publications

References 18 publications

Acoustic-Emission Study of Intermittency of Plastic Flow during Twinning and Dislocation Glide

Acoustic-Emission Study of Intermittency of Plastic Flow during Twinning and Dislocation Glide

Deformation patterning in finite-strain crystal plasticity by spectral homogenization with application to magnesium

Superplastic Behaviour of an Extruded AZ91 Alloy

Contact Info

Product

Resources

About