Controlling process instability for defect lean metal additive manufacturing

Qu, Minglei; Guo, Qilin; Escano, Luis I.; Nabaa, Ali; Hojjatzadeh, S. Mohammad H.; Young, Zachary A.; Chen, Lianyi

doi:10.1038/s41467-022-28649-2

Cited by 101 publications

(37 citation statements)

References 37 publications

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“…Therefore, the spattering needs to be solved during the in situ alloying process because it can lead to the deterioration of tensile performance by causing fusion defects. [ 43 ] The effective methods to eliminate the spattering include adjusting the parameter of shielding gas flow for removing the spatter from the printing zone and applying nanoparticle control on the instability of melting pool to eliminate large spatters, [ 44,45 ] which will be investigated in the future.…”

Section: Resultsmentioning

confidence: 99%

In situ Alloyed Medium Entropy Alloy Fabricated by Laser Powder Bed Fusion: Microstructure and Cryogenic Performance

Jia

et al. 2022

Adv Eng Mater

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An investigation is conducted into the feasibility to produce in situ alloyed medium entropy alloy containing four principal elements by laser powder bed fusion of the blended elemental powders. The effect of scan strategy, layer thickness, and laser power on in situ alloying is examined. It is revealed that the melting of Cr particles could be enhanced by increasing the remelting times of each building layer through the re‐scan strategy or reducing the powder layer thickness and by increasing the melting pool depth via large laser power. Besides, the combination of elemental uniformity and the low porosity in the printed alloy can be achieved. The accuracy of the nominal composition in the as‐printed sample could be ensured by the large remelting times combined with middle laser power, while an excessively large laser power could cause the loss of Cr element. Based on the high repetitive remelting process, the mechanism of pores elimination during in situ alloying is discussed. After the optimization, the as‐printed Fe60Co15Ni15Cr10 alloy fabricates with the re‐scan strategy or high laser power shows a tensile strength of ≈1140 MPa and an elongation of ≈0.39 under cryogenic loading. The as‐printed alloy overcomes the strength–ductility trade‐off at cryogenic temperature through the transformation‐induced plasticity.

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Section: Resultsmentioning

confidence: 99%

In situ Alloyed Medium Entropy Alloy Fabricated by Laser Powder Bed Fusion: Microstructure and Cryogenic Performance

Jia

et al. 2022

Adv Eng Mater

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“…Also wet coating of Al7075 (Vieth et al, 2020) and AlSi10Mg (Wang and Shi, 2020) with TiC nanoparticles by means of ultrasonication and wet ball milling was shown to be a feasible functionalization approach, although this process route has the drawback to demand for an additional drying step and potential contamination or oxidation of the alloy. Also for parts manufactured from Al6061/TiC composite powder prepared by planetary ball milling, a reduction of cracks was observed (Qu et al, 2022). Moreover, the authors observed improved PBF-LB/M processability characterized by a more stable process and the elimination of large spatters, which may lead to defective parts, for the composite powder system.…”

Section: Aluminum Alloy Feedstock Powdersmentioning

confidence: 92%

Dry powder coating in additive manufacturing

Schmidt

Peukert

2022

Front. Chem. Eng.

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Dry powder coating is used in many industries to tailor the bulk solid characteristics of cohesive powders. Within this paper, the state of the art of dry coating of feedstock materials for powder based additive manufacturing (AM) processes will be reviewed. The focus is on feedstock materials for powder bed fusion AM processes, such as powder bed fusion of polymers with a laser beam and powder bed fusion of metals with lasers or an electron beam. Powders of several microns to several ten microns in size are used and the feedstock’s bulk solid properties, especially the flowability and packing density are of immanent importance in different process steps in particular for powder dosing and spreading of powder layers onto the building area. All these properties can be tuned by dry particle coating. Moreover, possibilities to improve AM processability and to manipulate the resulting microstructure (c.f. grain refinement, dispersion strengthening) by adhering nanoparticles on the powders will be discussed. The effect of dry coating on the obtained powder properties along the whole AM process chain and the resulting part properties is assessed. Moreover, appropriate characterization methods for bulk solid properties of dry-coated AM powders are critically discussed.

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“…Currently, state-ofthe-art experimental characterization of the melting process uses high-speed imaging to capture the melting process and its dynamic interaction with the powder bed, such as powder spattering and denudation induced by the vapor plume [43] . Importantly, the use of in-situ operando X-ray synchrotrons has revealed many crucial information, such as the keyhole dynamics, its instability and pore formation [69] , and effects of nanoparticle additions [159] . Moreover, the combination of Schlieren imaging and in-situ x-ray operando imaging provides a simultaneous observation of the AM process and reveals the interaction between the vapor plume and melting process [70] .…”

Section: Mechanistic Modellingmentioning

confidence: 99%

Process parameter optimization of metal additive manufacturing: a review and outlook

Chia¹,

Wu²,

Wang³

et al. 2022

J Mater Inf

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The selection of appropriate process parameters is crucial in metal additive manufacturing (AM) as it directly influences the defect formation and microstructure of the printed part. Over the past decade, research efforts have been devoted to identifying "optimal" processing regimes for different materials to achieve defect-free manufacturing, which mostly involve costly trial-and-error experiments and computationally expensive mechanistic simulations. Hence, it is apropos to critically review the methods used to achieve the optimal process parameters in AM. This work seeks to provide a structured analysis of current methodologies and discuss systematic approaches toward general optimization work in AM and the process parameter optimization of new AM alloys. A brief review of process-induced defects due to process parameter selection is given and the current methods for identifying "optimal processing windows" are summarized. Research works are analyzed under a standard optimization framework, including the design of experiments and characterization, modelling and optimization algorithms. The research gaps that preclude multi-objective optimization in AM are identified and future directions toward optimization work in AM are discussed. With growing capabilities in AM, we should reconsider what the definition of the "optimal processing region".

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Controlling process instability for defect lean metal additive manufacturing

Cited by 101 publications

References 37 publications

In situ Alloyed Medium Entropy Alloy Fabricated by Laser Powder Bed Fusion: Microstructure and Cryogenic Performance

In situ Alloyed Medium Entropy Alloy Fabricated by Laser Powder Bed Fusion: Microstructure and Cryogenic Performance

Dry powder coating in additive manufacturing

Process parameter optimization of metal additive manufacturing: a review and outlook

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