Investigation of dissolution behavior of laves phase in inconel 718 fabricated by laser directed energy deposition
Investigation of dissolution behavior of laves phase in inconel 718 fabricated by laser directed energy deposition
复制标题
DOI：
10.1016/j.addma.2020.101055
复制
发表时间：
2020-03-01
影响因子：
11
通讯作者：
Tan, Hua
中科院分区：
文献类型：
--
作者：
Sui, Shang;Chen, Jing;Tan, Hua
Inconel 718的机械性能与Laves相的形态和尺寸密切相关，必须对Laves相的形态和尺寸进行定量控制，才能将Laves相的影响从有害变为有益。在本研究中，采用后热处理来调节激光定向能沉积Inconel718中Laves相的形态和尺寸，并研究了固溶热处理过程中Laves相的溶解行为。结果表明，在溶解过程中，Laves相的尖角和尖槽优先溶解，使Laves相的形态由长条状转变为颗粒状。用Johnson-Mehl-Avrami-Kolmogorov和Singh-Flemings模型研究了Laves相的溶解动力学。溶解初期既受Nb的远程扩散控制，又受界面反应控制。然而，随着Nb偏析程度的降低，界面反应成为主导。
The mechanical properties of Inconel 718 are closely related to the morphology and size of the Laves phase, which must be quantitatively controlled to change the effect of the Laves phase from deleterious to beneficial. In this study, post-heat treatment was used to regulate the morphology and size of the Laves phase in Inconel 718 fabricated using laser directed energy deposition, and the dissolution behavior of the Laves phase during solution heat treatment was investigated. The results indicated that the sharp corners and grooves of the Laves phase preferentially dissolved, causing the morphology of the Laves phase to change from a long-striped to granular shape during dissolution. The dissolution kinetics of the Laves phase were also investigated using the Johnson-Mehl-Avrami-Kolmogorov and Singh-Flemings models. The initial stage of dissolution was controlled by both the long-range diffusion of Nb and the interfacial reaction. However, with decreasing degree of Nb segregation, the interfacial reaction became dominant.