Journal Article

IMPULSE-2018-00201

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Experimental and numerical investigations of the γ″ and γ′ precipitation kinetics in Alloy 718

Drexler, A. (Corresponding author) ; Oberwinkler, B. ; Primig, S. ; Turk, C. ; Povoden-Karadeniz, E. ; Heinemann, A.MLZ* ; Ecker, W. ; Stockinger, M.

2018
Elsevier Amsterdam

Please use a persistent id in citations: doi:10.1016/j.msea.2018.03.013

Abstract: Predictive simulations of the γ′ and γ″ precipitates in the nickel-based superalloy Alloy 718 is needed for integrated computational materials engineering of technical components. But so far, no thermo-kinetic model is published for this alloy that is capable of reproducing simultaneously the precipitation evolution during, both, short and long time aging durations for an extended range of temperatures. The thermo-kinetic modeling was performed in the software package MatCalc, which uses the classical nucleation theory, the Svoboda-Fischer-Fratzl-Kozeschnik growth model and the ‘generalized broken bond theory’ for the interfacial energy. A combination of atom probe tomography, electron microscopy, small angle neutron scattering and sequential tensile tests are conducted to obtain the unknown kinetic evolution and strengthening parameters at the nano-, micro- and macro-scales for the model. The role of the physical association of the γ′ and γ″ precipitates and the effects of the precipitation strengthening are discussed. The resulting parametrized model successfully reproduces the measured local chemical composition, volume fractions, mean radii and precipitation strengthening contributions within a single set of model parameters up to 800 °C. Between 800 °C and 830 °C the model slightly over-predicts the kinetics.

Keyword(s): Engineering, Industrial Materials and Processing (1st) ; Materials Science (2nd)

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Contributing Institute(s):

1. SANS1

Experiment(s):

1. SANS-1: Small angle neutron scattering (NL4a)

Appears in the scientific report 2018

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Database coverage:
; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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