A Discrete Dendrite Dynamics Model for Epitaxial Columnar Grain Growth in Metal Additive Manufacturing with Application to Inconel
A Discrete Dendrite Dynamics Model for Epitaxial Columnar Grain Growth in Metal Additive Manufacturing with Application to Inconel
复制标题
DOI：
10.1016/j.addma.2020.101611
复制
发表时间：
2020-12-01
影响因子：
11
通讯作者：
To, Albert C.
中科院分区：
文献类型：
--
作者：
Paul, Santanu;Liu, Jian;To, Albert C.
外延柱状晶粒生长是具有立方晶胞晶格结构（面心立方（FCC）或体心立方（BCC））的金属部件（例如铬镍铁合金）的增材制造（AM）中普遍的微观结构特征。这些柱状晶粒是由基体或凝固金属中的部分熔融晶粒演变而来的。本文提出了一个有效的模型来模拟外延柱状枝晶的竞争生长。所提出的模型跟踪的动态变化的枝晶从离散点沿着固/液界面的准稳态熔池（MP）。这些动态变化包括生长树突的会聚和发散。该模型被扩展到预测大型3D零件的微观结构，并通过比较激光粉末床熔融（L-PBF）和电弧增材制造（WAAM）工艺的模拟结果进行实验验证。预测了L-PBF法生产的Inconel 718和WAAM法生产的Inconel 740 H的微观组织和极图。该模型预测比较以及与观察到的微观结构和极图的L-PBF和WAAM过程的结果。
Epitaxial columnar grain growth is a prevalent microstructural feature in the additive manufacturing (AM) of metal components such as Inconel, with cubic unit cell crystal lattice structure (face centered cubic (FCC) or body centered cubic (BCC)). These columnar grains evolve from the partly molten grains in the substrate or the solidified metal. This work proposes an efficient model to simulate the competitive growth of epitaxial columnar dendritic grains. The proposed model tracks the dynamic changes in the dendrites emanating from discrete points along the solid/liquid interface of a quasi-steady melt pool (MP). These dynamic changes include convergence and divergence of growing dendrites. The model is extended to predict the microstructure of large 3D parts and experimentally validated by comparing the simulation results for laser powder bed fusion (L-PBF) and wire-arc additive manufacturing (WAAM) processes. The microstructure and pole figures are predicted for Inconel 718 samples produced by L-PBF and Inconel 740H samples produced by WAAM processes. The model predictions compare well with the observed microstructure and pole figures results for both the L-PBF and WAAM processes.