Texture control during laser deposition of nickel-based superalloy

Dinda, G.P.; Dasgupta, A. K.; Mazumder, Jyoti

doi:10.1016/j.scriptamat.2012.06.014

Cited by 377 publications

(130 citation statements)

References 15 publications

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“…These grains are observed to grow across the layers of the deposited scans, which may be due to the epitaxial growth that took place in the preferred growth direction. A high thermal gradient at the liquid/solid interface at low solidification velocity is recognized [21,42] as the necessary conditions for the observed epitaxial growth and these conditions have been likely achieved during the wire-arc deposition of 718Plus in this work. Moreover, it is well established that FCC crystals have the fastest growth during solidification in the <100> direction.…”

Section: Microstructure Of Multi-layer Depositionmentioning

confidence: 75%

Microstructural Analyses of ATI 718Plus® Produced by Wire-ARC Additive Manufacturing Process

Asala

Khan

Andersson

et al. 2017

Metall Mater Trans A

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A detailed microstructural study of ATI 718Plus superalloy produced by the wire-arc additive manufacturing (WAAM) process was performed through the use of scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron probe micro-analysis (EPMA), and electron backscatter diffraction (EBSD). Extensive formation of eutectic solidification microconstituents including Laves and MC-type carbide phases, induced by micro-segregation, are observed in the build of the alloy in the as-deposited condition. Notwithstanding the significant segregation of niobium (Nb), which has been reported to promote the formation of the d-phase in ATI 718Plus, only g-phase particles are observed in the deposit. Excessive precipitation of g-phase particles is found to be linked to Laves phase particles that are partially dissolved in the deposit after post-deposition heat treatment (PDHT). The EBSD analysis shows a high textured build in the h100i directions with only a few misoriented grains at the substrate-deposit boundary and the top of the deposit. Investigation on the hardness of the build of the alloy, in the as-deposited condition, showed a softened zone about 2 mm wide at the deposited metal heat affected zone (DMHAZ), which has not been previously reported and potentially damaging to the mechanical properties. An extensive analysis with the use of both microstructural characterization tools and theoretical calculations shows that the DMHAZ has the lowest volume fraction of strengthening precipitates (c¢ and c¢¢) in terms of their number density, which therefore induces the observed softness. Delayed re-precipitation kinetics and the extent of the precipitation of c¢ and c¢¢ in the DMHAZ which is related to the diffusion of segregated solute elements from the interdendritic regions are attributed to this phenomenon. The microstructural analyses discussed in this work are vital to adequate understanding of properties of ATI 718Plus produced by the additive manufacturing process technique.

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Section: Microstructure Of Multi-layer Depositionmentioning

confidence: 75%

Microstructural Analyses of ATI 718Plus® Produced by Wire-ARC Additive Manufacturing Process

Asala

Khan

Andersson

et al. 2017

Metall Mater Trans A

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“…The formation of the final 3D texture is dependent on the laser scanning directions, and therefore, it could be predicted and controlled if the manufacturing strategy is known. Experimentally, the possibility to control microstructure through adjustments of the scanning strategy and process parameters has been presented for DED Ni-base alloys [34,50] and LPBF Ni- [51,52], and Al-alloys [48]. In the present investigation, to visualize microstructure and texture in the LPBF 316 L steel, the specimen was cross-sectioned so that the surface of interest was coplanar to the X 1 and Y 1 directions.…”

Section: Solidification Texturementioning

confidence: 99%

Microstructure, Solidification Texture, and Thermal Stability of 316 L Stainless Steel Manufactured by Laser Powder Bed Fusion

Krakhmalev

Fredriksson

Svensson

et al. 2018

Metals

144

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This article overviews the scientific results of the microstructural features observed in 316 L stainless steel manufactured by the laser powder bed fusion (LPBF) method obtained by the authors, and discusses the results with respect to the recently published literature. Microscopic features of the LPBF microstructure, i.e., epitaxial nucleation, cellular structure, microsegregation, porosity, competitive colony growth, and solidification texture, were experimentally studied by scanning and transmission electron microscopy, diffraction methods, and atom probe tomography. The influence of laser power and laser scanning speed on the microstructure was discussed in the perspective of governing the microstructure by controlling the process parameters. It was shown that the three-dimensional (3D) zig-zag solidification texture observed in the LPBF 316 L was related to the laser scanning strategy. The thermal stability of the microstructure was investigated under isothermal annealing conditions. It was shown that the cells formed at solidification started to disappear at about 800 • C, and that this process leads to a substantial decrease in hardness. Colony boundaries, nevertheless, were quite stable, and no significant grain growth was observed after heat treatment at 1050 • C. The observed experimental results are discussed with respect to the fundamental knowledge of the solidification processes, and compared with the existing literature data.

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“…[4,[12][13][14]. Many studies of high temperature oxidation in MCrAlY coatings with HVOF, APS, VPS or EB-PVD processes have been published [5,[11][12][13][14]; however, there have been few studies of the high-temperature behavior of NiCrAlY and NiCoCrAlY coatings obtained using laser techniques [15][16][17][18][19][20], and the laser cladding can be an novel alternative to thermal spray process, improving the integrity of the thermal barrier coatings. In this work, the high temperature behavior of MCrAlY laser cladding coatings (NiCoCrAlY and CoNiCrAlY) were investigated using the isothermal oxidation test in static air at 1100 °C for up to 200 h. The possible formation of oxides on the surface and a cross section of the oxidized sample were evaluated by XRD, FESEM and EDS after cutting by FIB.…”

Section: Introductionmentioning

confidence: 99%

High temperature oxidation behavior of laser cladding MCrAlY coatings on austenitic stainless steel

Pereira

Zambrano

Tobar

et al. 2015

Surface and Coatings Technology

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Texture control during laser deposition of nickel-based superalloy

Cited by 377 publications

References 15 publications

Microstructural Analyses of ATI 718Plus® Produced by Wire-ARC Additive Manufacturing Process

Microstructural Analyses of ATI 718Plus® Produced by Wire-ARC Additive Manufacturing Process

Microstructure, Solidification Texture, and Thermal Stability of 316 L Stainless Steel Manufactured by Laser Powder Bed Fusion

High temperature oxidation behavior of laser cladding MCrAlY coatings on austenitic stainless steel

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