High-temperature deformation mechanisms in a polycrystalline nickel-base superalloy studied by neutron diffraction and electron microscopy
High-temperature deformation mechanisms in a polycrystalline nickel-base superalloy studied by neutron diffraction and electron microscopy
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DOI：
10.1016/j.actamat.2014.04.028
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发表时间：
2014-08
期刊：
影响因子：
9.4
通讯作者：
E. Francis;B. Grant;J. Fonseca;P. Phillips;M. Mills;M. Daymond;M. Preuss
中科院分区：
文献类型：
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作者：
E. Francis;B. Grant;J. Fonseca;P. Phillips;M. Mills;M. Daymond;M. Preuss
为了研究 γ' 析出物尺寸对多晶镍基高温合金变形行为的影响，开发了具有单峰 γ' 尺寸分布的模型微观结构，并在 750 °C 下进行了加载实验。在加载过程中进行中子衍射测量，以记录γ和γ'相的弹性晶格应变响应。两点弹塑性自洽模型 (EPSC) 有助于解释弹性晶格应变响应。此外，通过（扫描）透射电子显微镜（STEM）分析了变形样品的微观结构。 EPSC 和 STEM 结果之间关于细 γ' 微观结构中 γ 和 γ' 相的联合变形以及中等 γ' 微观结构中低塑性应变的结果非常一致。随着 γ' 尺寸的增加和塑性变形程度的增加，两种实验方法都揭示了两相独立变形的趋势。
To study the effect of γ′ precipitate size on the deformation behaviour of a polycrystalline nickel-based superalloy, model microstructures with a unimodal γ′ size distribution were developed and subjected to loading experiments at 750 °C. Neutron diffraction measurements were carried out during loading to record the elastic lattice strain response of the γ and γ′ phase. A two-site elasto-plastic self-consistent model (EPSC) assisted in the interpretation of the elastic lattice strain response. In addition, the microstructures of the deformed specimens were analysed by (scanning) transmission electron microscopy (STEM). Excellent agreement was found between the EPSC and STEM results regarding a joint deformation of the γ and γ′ phase in the fine γ′ microstructures and for low plastic strains in the medium γ′ microstructures. With increasing γ′ size and increasing degree of plastic deformation, both experimental methodologies revealed a tendency of the two phases to deform independently.