Monitoring the precipitation of the hardening phase in the new VDM® Alloy 780 by in-situ high-temperature small-angle neutron scattering, neutron diffraction and complementary microscopy techniques
Monitoring the precipitation of the hardening phase in the new VDM® Alloy 780 by in-situ high-temperature small-angle neutron scattering, neutron diffraction and complementary microscopy techniques
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通过原位高温小角中子散射、中子衍射和互补显微镜技术监测新型 VDM® Alloy 780 中硬化相的沉淀
DOI：
10.1016/j.jallcom.2022.167203
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发表时间：
2022
影响因子：
6.2
通讯作者：
R. Gilles
中科院分区：
文献类型：
--
作者：
C. Solis;A. Kirchmayer;I. da Silva;F. Kümmel;S. Mühlbauer;P. Beran;B. Gehrmann;M. Haghighat;S. Neumeier;R. Gilles
硬化相析出过程在新型镍基高温合金的开发中起着重要的作用。在目前的工作中，我们采用了一种功能强大的互补表征技术组合来表征新型VDM®合金780中的原位γ'沉淀。在整个热处理过程中，原位飞行时间（TOF）中子衍射（ND）可以清楚地确定γ'相及其质量分数和与基体的失配度，而原位小角中子散射（SANS）可以提供精确的析出相尺寸分析。原子探针层析成像（APT）和扫描电子显微镜（SEM）提供了详细的微观结构表征和化学成分的阶段，必要的适当的中子散射数据评估。这一贡献揭示了更详细的信息的成核，生长和奥斯特瓦尔德熟化过程开始从早期沉淀阶段在散装样品中使用的互补微观结构的调查方法。在720 °C下析出物的成核和生长动力学取决于加热速率和样品预热历史中获得的尺寸分布。随后在620 °C下的热处理步骤（通常用于Ni基超合金中）不会导致类似的渐进沉淀或生长。在预期的工作温度（750 °C）下，SANS对完全沉淀硬化的样品进行了γ'相的基体扩散控制的Ostwald熟化过程的实时监测，结果表明，γ'相的粗化动力学比其他报道的镍基高温合金慢。
The hardening phase precipitation process plays an important role in the development of new Ni-base superalloys. In the present work, we apply a powerful combination of complementary characterization techniques to characterizein-situthe γ’ precipitation in the new VDM® Alloy 780. During the whole heat treatment process,in-situtime-of-flight (TOF) neutron diffraction (ND) unambiguously identified the γ’ phase as well as its weight fraction and the misfit with the matrix whilein-situsmall-angle neutron scattering (SANS) provided precise precipitates’ size analysis. Atom probe tomography (APT) and scanning electron microscopy (SEM) provided detailed microstructural characterization and chemical composition of the phases necessary for a proper neutron scattering data evaluation. This contribution reveals more detailed information on the nucleation, growth, and Ostwald ripening processes starting from the early precipitation stage in bulk samples using the complementary microstructure investigation methods. The nucleation and growth kinetics of precipitates at 720 °C depend on heating rates and the size distribution obtained in the pre-heating history of the sample. A subsequent heat treatment step at 620 °C, typically used in Ni-base superalloys, does not lead to similar progressive precipitation or growth. The expected matrix-diffusion-controlled Ostwald ripening process of the γ’ precipitates wasin-situmonitored by SANS on a full precipitation hardened sample at expected operating temperatures (750 °C) showing slower coarsening kinetics than other reported Ni-based superalloys.
影响因子：
9.4
作者：
Karge, L.;Gilles, R.;Petry, W.
通讯作者：
Petry, W.
影响因子：
9.4
作者：
Lawitzki, R.;Hassan, S.;Schmitz, G.
通讯作者：
Schmitz, G.