Sensitivity of Liquation Cracking to Deposition Parameters and Residual Stresses in Laser Deposited IN718 Alloy

Zhang, Yaocheng; Yang, Li; Chen, Tingyi; Pang, Song; Zhang, Weihui

doi:10.1007/s11665-017-2966-2

Cited by 12 publications

(2 citation statements)

References 39 publications

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“…Especially in superalloy welds [869][870][871][872][873][874][875] and dissimilar welds of superalloys with steels [876][877][878][879][880][881], Laves phases were consistently considered as highly detrimental to the mechanical properties. The effect of liquation cracking also plays an important role in the production of superalloys by additive manufacturing (AM) methods (e.g., [882,883]). Parts as well as coatings made of Ni-based superalloys (mostly IN718) are often produced by electron beam melting or laser AM, and a large number of investigations were performed to understand and control the formation and distribution of Laves phase during the AM process, see, for example, [884][885][886][887][888][889][890][891] to name but a few.…”

Section: Superalloysmentioning

confidence: 99%

Laves phases: a review of their functional and structural applications and an improved fundamental understanding of stability and properties

2020

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Laves phases with their comparably simple crystal structure are very common intermetallic phases and can be formed from element combinations all over the periodic table resulting in a huge number of known examples. Even though this type of phases is known for almost 100 years, and although a lot of information on stability, structure, and properties has accumulated especially during the last about 20 years, systematic evaluation and rationalization of this information in particular as a function of the involved elements is often lacking. It is one of the two main goals of this review to summarize the knowledge for some selected respective topics with a certain focus on non-stoichiometric, i.e., non-ideal Laves phases. The second, central goal of the review is to give a systematic overview about the role of Laves phases in all kinds of materials for functional and structural applications. There is a surprisingly broad range of successful utilization of Laves phases in functional applications comprising Laves phases as hydrogen storage material (Hydraloy), as magneto-mechanical sensors and actuators (Terfenol), or for wear- and corrosion-resistant coatings in corrosive atmospheres and at high temperatures (Tribaloy), to name but a few. Regarding structural applications, there is a renewed interest in using Laves phases for creep-strengthening of high-temperature steels and new respective alloy design concepts were developed and successfully tested. Apart from steels, Laves phases also occur in various other kinds of structural materials sometimes effectively improving properties, but often also acting in a detrimental way.

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Section: Superalloysmentioning

confidence: 99%

Laves phases: a review of their functional and structural applications and an improved fundamental understanding of stability and properties

2020

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“…Bucsek [15] analyzed microstructure refinement of single-crystal nickel-titanium shape memory alloy during thermal cycle. R. Cortes, Gopinath Muvvala and Yaocheng Zhang [16][17][18] discussed effect of process parameters on microstructure development and liquation cracking susceptibility of Ni-based superalloy Inconel 718 during gas tungsten arc welding with ErNiFeCr-2 filler wire and laser cladding. Xiaoqing Wang, Jianjun Xu and M. Pakniat [19][20][21] analyzed effect of process parameters on microstructure development and heat-affected zone liquation cracking susceptibility of Ni-based superalloys Inconel 718, IN738LC and Hastelloy during selective laser melting and laser solid forming.…”

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of Microstructure Anomalies during Laser Welding Nickel-Based Single-Crystal Superalloy Part II: Favorable Dendrite Tip Undercooling

Gao

2022

KEM

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Two important thermometallurgical factors, i.e. aluminum redistribution and dendrite tip undercooling, are numerically analyzed to better understand growth kinetics of microstructure development with favorable and unfavorable crystallographic orientations in three dimensions during advancement of Ni-Cr-Al ternary single-crystal melt-pool solidification interface to optimize microstructure stability within gamma γ phase. Inappropriate growth crystallography dominates profiles of aluminum redistribution and undercooling of dendrite tip in the crack-susceptible region, simultaneously. For beneficial (001)/[100] growth crystallography, the profiles of solid aluminum concentration and undercooling ahead of dendrite tip are clearly symmetrical throughout solidification interface. For detrimental (001)/[110] growth crystallography, the profiles of solid aluminum concentration and undercooling ahead of dendrite tip are quite asymmetrical within two sides of weld, and this asymmetrical phenomenon is of particular interest. The same energy of heat input is accessible to each half of molten pool, however, the difference of dendrite growth driving forces between right side and left side of weld pool kinetically exacerbates microstructure development. The complexity of (001)/[110] welding configuration is consistently attributable to larger overall solid aluminum concentration and undercooling of dendrite tip in [100] dendrite region than that of [010] dendrite region. In the two welding configurations, the size and shape of [001] dendrite growth region modifies growth kinetics of dendrite tip to extend columnar morphology of epitaxial growth for crack-resistant microstructure development with smaller solid aluminum concentration and narrower dendrite tip undercooling by either decrease of laser power or further increase of welding speed, while [100] dendrite growth region preferentially aids columnar/equiaxed transition (CET) with severe aluminum redistribution and wider dendrite tip undercoolig. The smaller heat input is imposed, the smaller solid aluminum concentration and narrower dendrite tip undercooling are crystallographically induced that is capable of elimination of metallurgical contributing factors for microstructure anomalies and vice versa. Optimum (001)/[100] growth crystallography and low heat input with decrease of laser power and increase of welding speed minimize columnar/equiaxed transition and stray grain formation, improve resistance to solidification cracking and ameliorate weld integrity, while (001)/[110] growth crystallography and high heat input with increase of laser power and decrease of welding speed significantly contribute to weldability exacerbation and microstructure degradation. The crystallography-dependent mechanism of efficient microstructure anomalies reduction, which is attributed to decreasing aluminum enrichment and undercooling ahead of dendrite tip, is therefore proposed. Consequently, comparison between calculation results and experiment results is plausible and acceptable. The usefulness application of this numerical analysis improves predictive capability and enables attractive microstructure control of single-crystal superalloys with similar materials properties.

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Influence of process parameter variation on the microstructure of thin walls made of Inconel 718 deposited via laser-based directed energy deposition with blown powder

et al. 2023

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In laser-based directed energy deposition (L-DED) of Inconel 718 the microstructure of the fabricated components strongly depends on the applied process parameters and the resulting solidification conditions. Numerous studies have shown that the process parameters deposition speed and laser power have a major influences on microstructural properties, such as dendrite morphology and segregation behavior. This study investigates how changes in these process parameters affect the microstructure and hardness when the line mass, and thus the resulting layer height, are kept constant. This enables the microstructural comparison of geometrically similar specimens that were manufactured with the same number of layers but severely different process parameters. This approach yields the benefit of almost identical geometrical boundary conditions, such as the layer-specific build-height and heat conducting cross section, for all specimens. For microstructural analysis scanning electron microscopy and energy dispersive X-ray spectroscopy were applied and the results evaluated in a quantitative manner. The microstructural features primary dendritic arm spacing, fraction and morphology of precipitated Laves phase as well as the spatially resolved chemical composition were measured along the build-up direction. The occurring cooling rates were calculated based on the primary dendritic arm spacing using semi-empirical models. Three different models used by others researchers were applied and evaluated with respect to their applicability for L-DED. Finally, microhardness measurements were performed for a baseline evaluation of the influence on the materials’ mechanical properties.

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Sensitivity of Liquation Cracking to Deposition Parameters and Residual Stresses in Laser Deposited IN718 Alloy

Cited by 12 publications

References 39 publications

Laves phases: a review of their functional and structural applications and an improved fundamental understanding of stability and properties

Laves phases: a review of their functional and structural applications and an improved fundamental understanding of stability and properties

Numerical Analysis of Microstructure Anomalies during Laser Welding Nickel-Based Single-Crystal Superalloy Part II: Favorable Dendrite Tip Undercooling

Influence of process parameter variation on the microstructure of thin walls made of Inconel 718 deposited via laser-based directed energy deposition with blown powder

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