Diffusion, defects and understanding the growth of a multicomponent 
interdiffusion zone between Pt-modified B2 NiAl bond coat and single crystal 
superalloy

Esakkiraja, Neelamegan; Gupta, Ankit; Jayaram, Vikram; Hickel, Tilmann; Divinski, Sergiy V.; Paul, Aloke

doi:10.1016/j.actamat.2020.04.016

アイテム詳細

登録内容を編集ファイル形式で保存

一時保存へ追加

タグ情報を表示リリース履歴を表示詳細要約

公開

学術論文

Diffusion, defects and understanding the growth of a multicomponent interdiffusion zone between Pt-modified B2 NiAl bond coat and single crystal superalloy

MPS-Authors

/persons/resource/persons180490

Gupta, Ankit
Computational Phase Studies, Computational Materials Design, Max-Planck-Institut für Eisenforschung GmbH, Max Planck Society;

/persons/resource/persons125180

Hickel, Tilmann
Computational Phase Studies, Computational Materials Design, Max-Planck-Institut für Eisenforschung GmbH, Max Planck Society;

External Resource

There are no locators available

Fulltext (restricted access)

There are currently no full texts shared for your IP range.

フルテキスト (公開)

公開されているフルテキストはありません

付随資料 (公開)

There is no public supplementary material available

引用

Esakkiraja, N., Gupta, A., Jayaram, V., Hickel, T., Divinski, S. V., & Paul, A. (2020). Diffusion, defects and understanding the growth of a multicomponent interdiffusion zone between Pt-modified B2 NiAl bond coat and single crystal superalloy. Acta Materialia, 195, 35-49. doi:10.1016/j.actamat.2020.04.016.

引用: https://hdl.handle.net/21.11116/0000-0009-FE8B-D

要旨

Composition-dependent diffusion coefficients are determined in B2-Ni(CoPt)Al system following the pseudobinary and pseudo-ternary diffusion couple methods, which would not be possible otherwise in a quaternary inhomogeneous material fulfilling the conditions to solve the equations developed based on the Onsager formalism. The end-member compositions to produce ideal/near-ideal diffusion profiles are chosen based on thermodynamic details. The pseudo-binary interdiffusion coefficients of Ni and Al decrease in the presence of Co but increase in the presence of Pt. The pseudo-ternary interdiffusion coefficients indicate that the main interdiffusion coefficients increase significantly in the presence of Pt. Marginal changes of the cross interdiffusion coefficients substantiate a minor change of the diffusional interactions between the components. The thermodynamic driving forces show opposite trends with respect to composition as compared to the changes of the interdiffusion coefficients advocating a dominating role of the Pt(Co)-induced modifications of point defect concentrations. DFT-based calculations revealed that Pt alloying increases the Ni vacancy concentration and decreases the activation energy for the triple defect diffusion mechanism. These findings explain the increase in the thickness of the interdiffusion zone between the B2-Ni(Pt)Al bond coat and the single crystal superalloy Rene N5 because of Pt addition. Furthermore, the EPMA and TEM analyses reveal the growth of refractory elements-enriched precipitates. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.