Temperature dependence of the stacking-fault Gibbs energy for Al, Cu, and Ni

• The temperature-dependent intrinsic stacking fault Gibbs energy is computed based on highly converged density-functional-theory (DFT) calculations for the three prototype face-centered cubic metals Al, Cu, and Ni. All relevant temperature-dependent contributions are considered including electronic, vibrational, magnetic, and explicit anharmonic Gibbs energy contributions as well as coupling terms employing state-of-the-art statistical sampling techniques. Particular emphasis is put on a careful comparison of different theoretical concepts to derive the stacking fault energy such as the axial-next-nearest-neighbor-Ising (ANNNI) model or the vacuum-slab approach. Our theoretical results are compared with an extensive set of previous theoretical and experimental data. Large uncertainties in the experimental data highlight the necessity of complementary parameter-free calculations. Specifically, the temperature dependence is experimentally unknown and poorly described by thermodynamic databases. Whereas CALPHAD derived data shows an increase of the stacking fault energy with temperature for two of the systems (Cu and Ni), our results predict a decrease for all studied systems. For Ni, the temperature induced change is in fact so strong that in the temperature interval relevant for super-alloy applications the stacking fault energy falls below one third of the low temperature value. Such large changes clearly call for a revision of the stacking fault energy when modeling or designing alloys based on such elements.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

Nyckelord

NTENEER PJH

1991

SOLID STATE COMMUNICATIONS

V78

P857

NTENEER PJH

1987

JOURNAL OF PHYSICS C-SOLID STATE PHYSICS

V20

PL883

NTENEER PJH

1991

JOURNAL OF PHYSICS-CONDENSED MATTER

V3

P8777 Yue

2007

PHYSICAL REVIEW B

V75

abowski B.

2009

PHYSICAL REVIEW B

V79

hnatek Michal

2009

PHYSICAL REVIEW B

V79

ermann F.

2009

PHYSICAL REVIEW B

V79

andl C.

2007

PHYSICAL REVIEW B

V76

ang S. L.

2012

JOURNAL OF PHYSICS-CONDENSED MATTER

V24

ban A. V.

2007

PHYSICAL REVIEW B

V75

ermann F.

2012

PHYSICAL REVIEW B

V85

tta Aditi

2009

SCRIPTA MATERIALIA

V60

P124 abowski B.

2011

PHYSICAL REVIEW B

V84

Campos M. F.

2008

Advanced Powder Technology VI6th International Latin American Conference on Power Technology

NOV 07-10

2007

Buzios

BRAZIL

V591-593

P708 tta A.

2011

COMPUTATIONAL MATERIALS SCIENCE

V50

P3342 andran Mahesh

2011

JOURNAL OF APPLIED PHYSICS

V109

ermann F.

2011

PHYSICAL REVIEW B

V83

basi Afshin

2011

ACTA MATERIALIA

V59

P3041 zyk M.

2011

SCRIPTA MATERIALIA

V64

P916

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