Investigation on Microsegregation of IN718 Alloy During Additive Manufacturing via Integrated Phase-Field and Finite-Element Modeling
Investigation on Microsegregation of IN718 Alloy During Additive Manufacturing via Integrated Phase-Field and Finite-Element Modeling
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DOI：
10.1007/s11665-018-3620-3
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发表时间：
2018-08
影响因子：
2.3
通讯作者：
X. Wang;P. Liu;Yi Ji;Y. Liu;M. H. Horstemeyer;L. Chen
中科院分区：
文献类型：
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作者：
X. Wang;P. Liu;Yi Ji;Y. Liu;M. H. Horstemeyer;L. Chen
在这项工作中，我们采用多尺度模型结合有限元法（FEM）和相场模型（PFM）来模拟增材制造IN718合金熔池中不同位置的凝固组织演变。具体而言，采用有限元法计算了宏观尺度下的熔池形状和相对热梯度。然后，将计算得到的热信息输入到PFM中进行微观模拟。最后，对不同部位的凝固组织形态和Laves相的形成进行了研究和比较。结果表明，温度梯度与优选晶向夹角较大的凝固部位在凝固过程中可在液体中形成较高的铌浓度，但形成连续长链Laves相颗粒的可能性较小。这一发现为了解IN718合金凝固过程中熔池内部的组织演变提供了依据。此外，研究结果表明，取向角较大的部位在凝固后具有较好的抗热裂性。
In this work, we apply a multi-scale model combining finite-element method (FEM) and phase-field model (PFM) to simulate the evolution of solidification microstructures at different locations within a molten pool of an additively manufactured IN718 alloy. Specifically, the FEM is used to calculate the shape of molten pool and the relative thermal gradientGat the macroscale. Then, the calculated thermal information is input into PFM for microstructure simulation. Finally, the morphology of solidification structures and formation of Laves phase at different sites are studied and compared. We found that the solidification site with a large angle between the temperature gradient and the preferred crystalline orientation could build up a high niobium (Nb) concentration in the liquid during solidification but has less possibility of forming continuous long chain morphology of Laves phase particles. This finding provides an understanding of the microstructure evolution inside the molten pool of IN718 alloy during solidification. Further, the finding indicates that the site with a large misorientation angle will have a good hot cracking resistance after solidification.