期刊
ACTA MATERIALIA
卷 209, 期 -, 页码 -出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.actamat.2021.116777
关键词
Directed Energy Deposition Additive; Manufacturing; Synchrotron X-ray diffraction; Synchrotron X-ray imaging; Laser Additive Manufacturing; IN718
资金
- MAPP: EPSRC Future Manufacturing Hub in Manufacture using Advanced Powder Processes [EP/P006566/1]
- Royal Academy of Engineering Chair in Emerging Technology [CiET1819/10]
- Rolls-Royce plc. via the Horizon 2020 Clean Sky 2 WP5.8.1 programme
- Office of Naval Research (ONR) [N6290919-1-2109]
The study revealed the governing mechanistic behaviour and microstructural evolution during Directed Energy Deposition Additive Manufacturing (DED-AM) using unique imaging and diffraction techniques, enhancing the understanding of solidification process and stress development in the alloy.
The governing mechanistic behaviour of Directed Energy Deposition Additive Manufacturing (DED-AM) is revealed by a combined in situ and operando synchrotron X-ray imaging and diffraction study of a nickel base superalloy, IN718. Using a unique DED-AM process replicator, real-space imaging enables quantification of the melt-pool boundary and flow dynamics during solidification. This imaging knowledge was also used to inform precise diffraction measurements of temporally resolved microstructural phases during transformation and stress development with a spatial resolution of 100 ?m. The diffraction quantified thermal gradient enabled a dendritic solidification microstructure to be predicted and coupled to the stress state. The fast cooling rate entirely suppressed the formation of secondary phases or recrystallisation in the solid-state. Upon solidification, the stresses rapidly increase to the yield strength during cooling. This insight, combined with the large solidification range of IN718 suggests that the accumulated plasticity exhausts the ductility of the alloy, causing liquation cracking. This study has revealed the mechanisms that govern the formation of highly non-equilibrium microstructures during DED-AM. ? 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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