Laves phase control of Inconel 718 alloy using quasi-continuous-wave laser additive manufacturing
Laves phase control of Inconel 718 alloy using quasi-continuous-wave laser additive manufacturing
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使用准连续波激光增材制造对 Inconel 718 合金进行 Laves 相位控制
DOI：
10.1016/j.matdes.2017.03.004
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发表时间：
2017-05-15
影响因子：
8.4
通讯作者：
Song, Lijun
中科院分区：
文献类型：
--
作者：
Xiao, Hui;Li, Simeng;Song, Lijun
已知Nb偏析和Laves相的形成对Inconel718的机械性能不利。然而，抑制Nb偏析和Laves相形成的有效措施仍然缺乏。在这项工作中，使用准连续波(QCW)激光添加制造(LAM)来控制Nb的偏析和Laves相的形成。研究了熔池的热行为、制备样品的组织演变和对时效处理的力学响应。与连续波(CW)LAM相比，QCW-LAM的冷却速度提高了一个数量级，熔池凝固时间缩短，枝晶组织细小，Nb偏析减少，Nb偏析减少，Laves相颗粒细小且分散。此外，由于Nb偏析减少，获得了细小的离散Laves相和细化的枝晶组织，QCW样品对时效处理表现出良好的响应，具有更高的硬度和更理想的拉伸性能。时效后的Inconel718合金的抗拉强度(约1404.1 Mpa)、屈服强度(约1120.6 Mpa)和塑性(约12.4%)均高于变形Inconel718合金的ASTM值。(C)2017爱思唯尔有限公司。保留所有权利。
Nb segregation and Laves phase formation are known to be detrimental to mechanical properties of Inconel 718. However, effective efforts to suppress Nb segregation and Laves phase formation are still lacking. In this work, a quasi-continuous-wave (QCW) laser additive manufacturing (LAM) is used to control Nb segregation and Laves phase formation. Thermal behaviors of the molten pool, microstructural evolution and mechanical response of the fabricated samples to aging treatment were investigated. Compared to continuous wave (CW) LAM, QCW-LAM results in a refined and equiaxed dendrite microstructure, a reduced Nb segregation, and attended fine and discrete Laves phase particles, due to an improved cooling rate with one order of magnitude and a decreased solidification time of the molten pool. In addition, the QCW sample shows a good response to aging treatment with a higher hardness and more desired tensile properties due to the reduced Nb segregation, the obtained fine discrete Laves phase and the refined dendrite microstructure. The tensile strength (similar to 1404.1 MPa), the yield strength (similar to 1120.6 MPa) and the ductility (similar to 12.4 pct) of the aged QCW sample are higher than the ASTM limits of the wrought Inconel 718 alloy. (C) 2017 Elsevier Ltd. All rights reserved.