The influence of Laves phases on the high-cycle fatigue behavior of laser additive manufactured Inconel 718
The influence of Laves phases on the high-cycle fatigue behavior of laser additive manufactured Inconel 718
复制标题
Laves相对激光增材制造的Inconel 718高周疲劳行为的影响
DOI：
10.1016/j.msea.2017.03.098
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发表时间：
2017-05-17
期刊：
影响因子：
6.4
通讯作者：
Huang, Weidong
中科院分区：
文献类型：
--
作者：
Sui, Shang;Chen, Jing;Huang, Weidong
本文对锻造Inconel 718和LAMed Inconel 718进行了高周疲劳试验（T=650 ℃，f=110 Hz，R=0.1，K-t=1）的对比研究。结果表明，Laves相对高周疲劳性能的影响取决于所施加的应力幅。在低应力幅下，大部分Laves相保持其原始形貌。疲劳裂纹在裂纹前停止或绕过裂纹，这意味着未断裂的Laves相在阻碍裂纹扩展方面起着重要作用。因此，LAMed Inconel 718的高周疲劳寿命上级锻造Inconel 718。然而，在高应力幅下，裂纹扩展区域中几乎所有的Laves相分裂成较小的碎片，其中部分与奥氏体基体分离。在界面处形成了微观孔洞或裂纹，为疲劳裂纹的扩展提供了通道。在这种情况下，Laves相是有害的，导致LAMed Inconel 718与锻造Inconel 718相比疲劳性能下降。
In this paper, a comparative study of high-cycle fatigue tests (T=650 degrees C,f=110 Hz, R=0.1, K-t=1) were carried out with wrought Inconel 718 and LAMed Inconel 718. The results show that the influences of the Laves phases on high-cycle fatigue properties are based on the applied stress amplitudes. At a low stress amplitude, most of the Laves phases held their original morphologies. The fatigue cracks stopped in front or detoured around them, which means that the unbroken Laves phases play an important role in hindering crack propagation. In this way, the high-cycle fatigue life of LAMed Inconel 718 was superior to that of wrought Inconel 718. However, at a high stress amplitude almost all of the Laves phases in the crack propagation region splintered into smaller fragments, parts of which separated from the austenite matrix. Microscopic holes or cracks were formed at the interface, which provided passages for the fatigue cracks to propagate. In this case, the Laves phases were harmful, leading to the degradation of fatigue performance in LAMed Inconel 718 compared with wrought Inconel 718.