High-temperature and low-stress creep anisotropy of single-crystal superalloys
High-temperature and low-stress creep anisotropy of single-crystal superalloys
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DOI：
10.1016/j.actamat.2013.01.052
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发表时间：
2013-05
期刊：
影响因子：
9.4
通讯作者：
L. Jácome;P. Nörtershäuser;J. Heyer;A. Lahni;J. Frenzel;A. Dlouhý;C. Somsen;G. Eggeler
中科院分区：
文献类型：
--
作者：
L. Jácome;P. Nörtershäuser;J. Heyer;A. Lahni;J. Frenzel;A. Dlouhý;C. Somsen;G. Eggeler
研究了单晶镍基高温合金LEK 94的高温低应力蠕变（1293K，160MPa），比较了微型蠕变试样在[001]和[110]方向的拉伸蠕变行为。在蠕变的早期阶段，[001]方向载荷表现出更高的最小蠕变速率，因为更多的微观晶体滑移系统被激活，γ/γ'界面处的位错网络更好地适应晶格失配，并且γ通道更宽。在蠕变速率达到最小值后，蠕变速率随着[110]拉伸载荷的应变而增加得更加强烈。这可能与[110]拉伸蠕变期间漂流的性质有关，这导致γ通道的拓扑结构更加开放。与[100]拉伸蠕变相比，这也可能与更频繁的γ′切削事件有关。
The high-temperature and low-stress creep (1293K, 160MPa) of the single-crystal Ni-based superalloy LEK 94 is investigated, comparing the tensile creep behavior of miniature creep specimens in [001] and [110] directions. In the early stages of creep, the [001]-direction loading shows higher minimum creep rates, because a greater number of microscopic crystallographic slip systems are activated, the dislocation networks at γ/γ′ interfaces accommodate lattice misfit better, and γ channels are wider. After the creep rate minimum, creep rates increase more strongly as a function of strain for [110] tensile loading. This may be related to the nature of rafting during [110] tensile creep, which results in a more open topology of the γ channels. It may also be related to more frequent γ′ cutting events compared with [100] tensile creep.