PSI - Issue 23

Kristián Máthis et al. / Procedia Structural Integrity 23 (2019) 51–56 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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It means that the alloying influences the anelastic strain only through the twin boundary mobility. At low Al concentrations there is a higher twinned volume fraction but lower twin boundary density – this leads to quick development of relaxed twinned structure and lower anelasticity. In contrast, for high Al concentrations high number of thin twins forms (i.e. high twin boundary density, lower twinned volume fraction), which can easily detwin. Thus, the observed anelastic strain for Mg9Al is also higher.

Fig. 4. Dependence of the anelastic strain on the change in the twinned volume fraction during unloading.

4. Conclusions

The solute concentration dependence of the anelastic behavior in Mg-Al alloys was investigated with a combination of several in-situ experimental methods. The following conclusions can be drawn:  Above the yield stress, the magnitude of the anelastic strain increases with the increasing alloying content  The anelastic effect is closely connected to the twin boundary mobility during the unloading. The low Al concentration leads to quick forming of stable twin structure with low probability for detwinning and low anelastic strain. In contrast, thin twins, formed for high Al concentration can easily detwin and cause a large anelastic effect.

Acknowledgements

The authors are grateful for the financial support of the Czech Science Foundation under contract 18-07140S.

References

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