Evaluate the effect of melt pool convection on grain structure of IN625 in laser melting process using experimentally validated process-structure modeling

Xiong, Feiyu; Gan, Zhengtao; Chen, Jiawei; Lian, Yuan

doi:10.1016/j.jmatprotec.2022.117538

Cited by 40 publications

(6 citation statements)

References 22 publications

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“…This phenomenon can be explained through a closer look at the spatial imaging of the laser scan, as shown in Figure 6. The strength of heat flow is prioritized first through thickness and second laterally, with laterally being the perpendicular direction relative to the scan [51][52]. Another possible explanation for this phenomenon could be relating it to the high orthotropic properties of IN625, where these elastic properties in two or three planes could be perpendicular to each other.…”

Section: Thermal Profile Impact On Microstructural Evolutionmentioning

confidence: 99%

“…This observation is evidence of the importance in understanding the thermal history within laser processing and the value that modeling such as the presented numerical model can provide in understanding laser processing parameters and their impact on final properties. As demonstrated in previous work, solidification microstructure can be examined and customized by understanding heat flow effect on grain evolution through the use of coupling numerical modeling methods (such as the one presented in this research) with methods such as cellular automation method [52], an area of simulation investigation worth further exploration to better understand and predict the process-microstructure relationship.…”

Section: Thermal Profile Impact On Microstructural Evolutionmentioning

confidence: 99%

See 1 more Smart Citation

Thermal Profile Modeling and Microstructural Evolution in Laser Processing of Inconel 625 Plates

Lawson¹,

Ghayoor²,

Tabei³

et al. 2023

Preprint

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Thermal modeling is used in additive manufacturing laser processes to predict microstructural evolution of the materials under specified process conditions and parameters. The objective of this study was to develop, analyze and compare two predictive models: an analytical model and a numerical model for laser processing of materials of Inconel 625. These models were compared with experimental results for thermal profiling, and the effect of thermal profiles on microstructure of the experimental samples was explored. The three approaches; analytical modeling, numerical modeling, and experimental results were evaluated against thermal profile histories and correlated to microstructural evolution in laser processing. Maximum temperatures in the thermal profile of both models were shown in good agreement when compared to the experimental results. Cooling curves were also correlated with microstructure in terms of grain size, morphology, orientation, and texture evolution, with findings that match previously reported results. This research validates the proposed numerical model for examining optimal laser processing conditions for IN625 through both thermal history and microstructure comparison with experimental results using literature derived thermo-physical material properties.

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Section: Thermal Profile Impact On Microstructural Evolutionmentioning

confidence: 99%

Section: Thermal Profile Impact On Microstructural Evolutionmentioning

confidence: 99%

Thermal Profile Modeling and Microstructural Evolution in Laser Processing of Inconel 625 Plates

Lawson¹,

Ghayoor²,

Tabei³

et al. 2023

Preprint

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show abstract

“…The transport and distribution of solute elements at the microstructural “sub-grain” scale (10 -6 ~10 -7 m), including the solute partitioning between the cellular (dendritic) trunk and the intercellular (interdendritic) region, as well as the non-equilibrium nature of the solidification process, are not well understood by the previously reported model frameworks 26 , 27 . Besides, as uncovered by X-ray synchrotron radiation imaging experiments 28 , 29 and macro-scale simulations 30 , 31 , the melt flow during AM process can make significant impact on the solute transport and hence presumably alters the as-printed microstructure 32 – 34 . In the recent progress on the modelling of AM 26 , the factors including the effect of melt convection and solute partition on the solute distribution, and thus on the crystal growth, have always been neglected in the multi-grid method 35 , 36 and the microstructural simulation under characteristic thermal conditions 37 , 38 .…”

Section: Introductionmentioning

confidence: 99%

Solute trapping and non-equilibrium microstructure during rapid solidification of additive manufacturing

Ren,

Li,

Zhang

et al. 2023

Nat Commun

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Solute transport during rapid and repeated thermal cycle in additive manufacturing (AM) leading to non-equilibrium, non-uniform microstructure remains to be studied. Here, a fully-coupled fluid dynamics and microstructure modelling is developed to rationalise the dynamic solute transport process and elemental segregation in AM, and to gain better understanding of non-equilibrium nature of intercellular solute segregation and cellular structures at sub-grain scale during the melting-solidification of the laser powder bed fusion process. It reveals the solute transport induced by melt convection dilutes the partitioned solute at the solidification front and promotes solute trapping, and elucidates the mechanisms of the subsequent microstructural morphology transitions to ultra-fine cells and then to coarse cells. These suggest solute trapping effect could be made used for reducing crack susceptibility by accelerating the solidification process. The rapid solidification characteristics exhibit promising potential of additive manufacturing for hard-to-print superalloys and aid in alloy design for better printability.

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“…It is an unquestionable fact that convection has a significant effect on the morphology of solidified dendrites (Nabavizadeh et al (2020)). Convection can promote or hinder the growth of dendrites, and the microstructure of dendrites is completely different from that of pure diffusion (Geng et al (2020); Xiong et al (2022)). The research on the effect of convection on the evolution of solidification organization is relatively fast in China, but there is still scarce of foreign research in this area.…”

Section: Introductionmentioning

confidence: 99%

Application of phase field model coupled with convective effects in binary alloy directional solidification and roll casting processes

Zeng

Chen

et al. 2022

Front. Mater.

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Based on the Kim-Kim-Suzuki (KKS) phase field model coupled with the thermodynamic parameters, the transformation process from columnar dendrites to equiaxed crystals during directional solidification of aluminium alloy was simulated, and the effects of phase field parameters on the growth morphology and dendrite segregation were discussed. Furthermore, considering the effect of the microcosmic flow field, the convection influence gradient term is introduced into KKS formula near the solid-liquid interface, and the phase field model considering flow field was applied to the inherent convective environment of the actual roll casting process, also the multiple dendrites growth behavior of magnesium alloy under the action of microscopic convection was further explored. When coupling calculation of microscopic velocity field and pressure field, the staggered grid method was used to deal with the complex interface. The combined solution of Marker in Cell (MAC) algorithm and phase field discrete calculation was realized. In order to further describe the influence of convection on the solidification process, the roll casting experiments are used to verify the impact growth of multiple dendrites under convection. The results show that the dendrites undergo solute remelting and the dendrites melt into equiaxed crystals, showing the phenomenon of Columnar to Equiaxed Transition (CET).

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Evaluate the effect of melt pool convection on grain structure of IN625 in laser melting process using experimentally validated process-structure modeling

Cited by 40 publications

References 22 publications

Thermal Profile Modeling and Microstructural Evolution in Laser Processing of Inconel 625 Plates

Thermal Profile Modeling and Microstructural Evolution in Laser Processing of Inconel 625 Plates

Solute trapping and non-equilibrium microstructure during rapid solidification of additive manufacturing

Application of phase field model coupled with convective effects in binary alloy directional solidification and roll casting processes

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