Ab-Initio Guided Design of Twinning Induced

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Nov 28, 2016 - (ε) = K M G b/D. Fe-30.4Mn-8Al-1.2C (wt%), as-quenched, no kappa precipitates. Welsch et al. (2016) Acta Materialia, 116, pp. 188.

Ab-Initio Guided Design of Twinning Induced Plasticity and Weight Reduced Austenitic Steels D. Ponge, B. Gault, C. Liebscher, P. Dey, G. Dehm, E. Welsch, M. Yao, S.-L. Wong, T. Hickel, M. Lipinska-Chwalek, J. Neugebauer, U. Prahl, M. Madivala, C. Scheu, J. Neugebauer, W. Bleck, D. Raabe

Düsseldorf, Germany

Dierk Raabe, MRS Fall Meeting, Nov 28th 2016, Boston, USA

Steinmetz et al. (2013) Acta Mater 61, pp. 494

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APT

Mn Atoms

Steinmetz et al. (2013) Acta Mater 61, pp. 494

http://damask.mpie.de

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APT

Mn Atoms

Steinmetz et al. (2013) Acta Mater 61, pp. 494

http://damask.mpie.de

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Introduction: dependence of deformation on SFE lower SFE

high-Mn (15-30%) γ (fcc) cells → γ (fcc) planar → γ (fcc+kappa) planar → γ (fcc+twins) → ε (hcp) → α’ (bcc/bct)

medium-Mn (5-12%)

high-Mn+Al

ΔGγ→ε >> 0 Critical stress for twin growth:

Critical stress for ε-martensite growth:

ΔGγ→ε