Investigations on the role of Ce on the transient oxidation of β-NiAl

IF 4.8 2区材料科学 Q2 CHEMISTRY, PHYSICAL

Intermetallics Pub Date : 2025-09-28 DOI:10.1016/j.intermet.2025.109002

Santosh Kumar, Pratik K. Ray

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引用次数: 0

Abstract

The role of 1 atom % Ce addition on transient oxidation behaviour of β-NiAl alloy at 1100 °C has been investigated to observe the spatio-temporal changes across the alloy grain boundaries during initial 2 h of oxidation. We observed that Ce doping in β-NiAl results in an increase in scale growth kinetics as compared to undoped β-NiAl. Oxide surface morphology and cross-sectional features were examined under the scanning electron microscope – to observe the morphological changes and oxidation pathways in both alloys. The role of diffusing species (Al, Ce and O) on scale growth behaviour has been investigated. During oxidation, a ridge shaped Al₂O₃ scale morphology is developed over the undoped alloy. With Ce doping in β-NiAl, the network of Al₂O₃ ridges disappears. A needle shaped Al₂O₃ morphology is observed as a result of Ce doping in β-NiAl. The cross-sectional morphology revealed a uniform external scale (with scale thickness ∼ 5 μm) in undoped alloy. However, a significant oxygen ingress beneath the external scale is observed in the Ce doped alloy causing internal and intergranular oxidation. The discontinuities present in Ce doped alloy in the form of secondary precipitates provides the pathways for internal O diffusion. Further, the significant change in diffusion flux of Al due the change in local alloy chemistry results in the development of a non-uniform scale (scale thickness varies from 4 to 11 μm) in Ce doped alloy.

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Ce对β-NiAl瞬态氧化作用的研究

研究了在1100℃时加入1个原子% Ce对β-NiAl合金瞬态氧化行为的影响，观察了氧化开始2 h时合金晶界的时空变化。我们观察到，与未掺杂的β-NiAl相比，Ce掺杂在β-NiAl中导致了尺度生长动力学的增加。在扫描电子显微镜下观察了两种合金的表面形貌和横截面特征，以观察两种合金的形态变化和氧化途径。研究了扩散物质（Al， Ce和O）在水垢生长行为中的作用。在氧化过程中，在未掺杂的合金上形成脊状的Al2O3鳞状形貌。在β-NiAl中掺入Ce后，Al2O3的脊网消失。在β-NiAl中掺杂Ce，观察到针状Al2O3的形貌。截面形貌显示，未掺杂合金表面有均匀的鳞片（鳞片厚度约5 μm）。然而，在Ce掺杂合金中，在外部尺度下观察到明显的氧气进入导致内部和晶间氧化。Ce掺杂合金中以二次沉淀形式存在的不连续性为内部O扩散提供了途径。此外，由于局部合金化学性质的改变，Al的扩散通量发生了显著变化，导致Ce掺杂合金中形成了不均匀的水垢（水垢厚度在4 ~ 11 μm之间）。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Intermetallics 工程技术-材料科学：综合

CiteScore

7.80

自引率

9.10%

发文量

291

审稿时长

37 days

期刊介绍： This journal is a platform for publishing innovative research and overviews for advancing our understanding of the structure, property, and functionality of complex metallic alloys, including intermetallics, metallic glasses, and high entropy alloys. The journal reports the science and engineering of metallic materials in the following aspects: Theories and experiments which address the relationship between property and structure in all length scales. Physical modeling and numerical simulations which provide a comprehensive understanding of experimental observations. Stimulated methodologies to characterize the structure and chemistry of materials that correlate the properties. Technological applications resulting from the understanding of property-structure relationship in materials. Novel and cutting-edge results warranting rapid communication. The journal also publishes special issues on selected topics and overviews by invitation only.