Differentiation of γ′ and γ"-precipitates in Inconel 718 by a complementary study with small-angle neutron scattering and analytical microscopy
Differentiation of γ′ and γ"-precipitates in Inconel 718 by a complementary study with small-angle neutron scattering and analytical microscopy
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DOI：
10.1016/j.actamat.2018.10.014
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发表时间：
2019-01-15
期刊：
影响因子：
9.4
通讯作者：
Schmitz, G.
中科院分区：
文献类型：
--
作者：
Lawitzki, R.;Hassan, S.;Schmitz, G.
我们提出了一种区分和量化镍基高温合金Inconel 718中两个强化相gamma'和gamma ''的实验方法。到目前为止，这只能通过在纳米到微米范围内评估样品体积的技术来实现。在这项研究中，可靠的沉淀物的体积分数，获得和计算从异位小角中子散射（SANS）不同的热处理试样。为了解释SANS曲线，建立了一个结构模型，利用透射电子显微镜（TEM）和原子探针断层扫描（APT）测量的互补信息。用透射电子显微镜（TEM）对沉淀物进行了物相鉴定、尺寸分布、形貌和晶体学分析。APT提供了计算每个相的散射对比度所必需的组成信息。作为使用体中子衍射进行量化的好处，分析了几十立方毫米的体积，从而获得了明显更好的统计数据。所测得的γ "体积分数明显低于以前的工作中所述，但现在很好地满足化学质量平衡。(C)2018 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
We present an experimental method to distinguish and quantify the two strengthening phases gamma' and gamma '' in the nickel-based superalloy Inconel 718. So far, this was only achieved by techniques that evaluated sample volumes in the nano-to micrometer range. In this study, reliable volume fractions of the precipitates were obtained and calculated from ex-situ small-angle neutron scattering (SANS) on differently heat treated specimens. For interpretation of the SANS curves, a structural model was set up, using complementary information from measurements by transmission electron microscopy (TEM) and atom probe tomography (APT). Phase identification, as well as size distributions, morphologies and crystal-lographic information of the precipitates were obtained by TEM. APT provided compositional information, which is necessary to calculate the scattering contrast of each phase. As a benefit of using bulk neutron diffraction for quantification, volumes of a few tens of cubic millimeters are analyzed and thus, significantly better statistics are obtained. The measured gamma '' volume fractions are remarkably lower than stated in previous works, but now well fulfill the chemical mass balance. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.