Determination of the high temperature elastic properties and diffraction elastic constants of Ni-base superalloys
Determination of the high temperature elastic properties and diffraction elastic constants of Ni-base superalloys
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DOI：
10.1016/j.matdes.2015.09.152
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发表时间：
2016-01
影响因子：
8.4
通讯作者：
P. Aba-perea;T. Pirling;P. Withers;J. Kelleher;S. Kabra;M. Preuss
中科院分区：
文献类型：
--
作者：
P. Aba-perea;T. Pirling;P. Withers;J. Kelleher;S. Kabra;M. Preuss
两种镍基高温合金 Inconel 718（淬火和时效）和 Udimet 720LI（时效）的衍射弹性常数和相特定弹性常数已通过使用飞行时间中子衍射的原位加载确定为温度的函数。实验在室温至 750 °C 之间进行，以支持未来时效处理期间的原位残余应力分析。对于 Udimet 720LI，Rietveld 对衍射数据的分析揭示了 γ 和 γ' 的弹性常数非常相似，这表明可以使用简化的单相模型来分析衍射数据。正如人们所预料的那样，Inconel 718 的杨氏模量随着温度的升高而下降，从室温下的 220 GPa 降至 700 °C 下的 140 GPa，曲线在 500 °C 左右出现拐点。在研究的温度范围内，Udimet 720 的刚度大约为 15–20 GPa，并且各个峰值以类似的方式下降。此外，在所有情况下，(311)、(220)、(200)和(111)反射的衍射弹性常数(DEC)根据晶体各向异性因子线性变化，正如对于所有温度所预期的那样，各向异性程度随着温度的升高而增加。
The diffraction elastic constants and phase specific elastic constants of two Ni-base Superalloys, Inconel 718 (as-quenched and aged) and Udimet 720LI (aged) have been determined as a function of temperature by means of in-situ loading using time-of-flight neutron diffraction. Experiments were carried out between room temperature and 750 °C in order to support future in-situ residual stress analyses during ageing treatments. In the case of Udimet 720LI, Rietveld analysis of the diffraction data revealed very similar elastic constants for γ and γ′ suggesting a simplified single-phase model can be used for the analysis of the diffraction data. As one would expect, the Young's moduli fall with increasing temperature for Inconel 718 from 220 GPa at room temperature to 140 GPa at 700 °C with a knee in the curve at around 500 °C. The Udimet 720 is around 15–20 GPa stiffer over the temperature range studied and the individual peaks fall in a similar manner. In addition in all cases the diffraction elastic constants (DECs) of the (311), (220), (200) and (111) reflections varied linearly according to the crystallographic anisotropy factor as expected for all temperatures with the degree of anisotropy increasing with increasing temperature.