期刊
MATERIALS & DESIGN
卷 196, 期 -, 页码 -出版社
ELSEVIER SCI LTD
DOI: 10.1016/j.matdes.2020.109117
关键词
Co-Cr-Mo; Selective laser melting; Computation fluid dynamics; Columnar to Equiaxed transition; Unconstrained and constrained solidification
资金
- Digital Manufacturing and Design Innovation Institute (DMDII)
- GE Global Research [084869]
- GE Global Research researchers
Processing parameters during laser based additive manufacturing affect the fluid flow, heat transfer and solidification characteristics in the melt pool, leading to microstructural variants of texture, grain size, and morphology. A finite volume based Computational Fluid Dynamics (CFD) model coupled with solidification physics has been developed to predict melting, flow, solidification, and resulting microstructural characteristics during such processes. The variation of texture, grain size and columnar/equiaxed morphology of the grains with laser power and speed has been verified against experiments. The difference in cooling curves and evolution of temperature gradients and cooling rates during solidification leading to a difference in each microstructural variant has been identified. Lower laser power and higher scan rates lead to unconstrained solidification with small variation of solidification times across the melt pool depth leading to finer grain structure with lower grain boundary (GB) misorientations. On the other hand, higher power and lower scan rates lead to constrained solidification, with huge variations in solidification times, coarser grains and highly misoriented grain boundaries. The desirable microstructure has been found to be predominantly fine grained based on mechanical strength measured using nanoindentation tests. Hunt's criterion-based processing maps for understanding the morphological variants has been prepared for systematic design of microstructure during the process. (c) 2020 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据