Selective laser melting of dense and crack-free AlCoCrFeNi2.1 eutectic high entropy alloy: Synergizing strength and ductility

He, Lijuan; Wu, Shiwei; Dong, Anping; Tang, Haibin; Du, Dafan; Zhu, Guoliang; Sun, Baode; Yan, Wentao

doi:10.1016/j.jmst.2021.11.049

Cited by 62 publications

(9 citation statements)

References 63 publications

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“…However, the L-PBF manufactured Ni 30 Co 30 Cr 10 Fe 10 Al 18 W 1 Mo 1 (at. %) EHEA showed serious softening above 650 °C, as illustrated by Yang et al [68] . Heat treatment may be needed to further improve the high-temperature mechanical properties of as-printed EHEAs by optimizing the microstructure and phase constitution.…”

Section: Am Of Eheasmentioning

confidence: 80%

“…Precipitation-strengthened HEAs were therefore designed to break the strength-ductility trade-off of single-phase HEAs. Designing [20,[59][60][61][62][63][64][65] ; eutectic HEAs [68][69][70][71][72][73][74] ; HEAs strengthened by ceramics [75][76][77][78][79][80][81][82][83] ; HEAs strengthened by L1 . FCC: face-centered-cubic; HEAs: high-entropy alloys.…”

Section: Key Issues For Hea Design and Ammentioning

confidence: 99%

“…AM processes, including PBF and DED, have shown many significant advantages in fabricating HEA components compared to traditional processing methods, such as casting, wrought and welding. Until now, many kinds of HEAs have been manufactured by AM methods, including single-phase HEAs (FCC or BCC) [20,[59][60][61][62][63][64][65][66][67] , EHEAs (FCC + BCC) [68][69][70][71][72][73][74] and precipitation-strengthened HEAs [75][76][77][78][79][80][81][82][83][84][85][86][87][88][89] . Figure 3 summarizes the tensile yield strength against the uniform elongation of as-printed HEAs at room temperature.…”

Section: Am Of Heasmentioning

confidence: 99%

“…As-printed FCC HEAs show large ductility but low strength [20,[59][60][61][62][63][64][65] . In addition, for EHEAs manufactured by L-PBF, their tensile properties vary over a wide range, which may be caused by the relative proportions between the FCC and BCC phases and different microstructural features [68][69][70][71][72][73][74] . Another approach to strengthening the soft FCC matrix is to introduce second hardening phases, such as incoherent ceramic particles (carbides [75][76][77][78][79][80] , nitrides [81,82] , oxides [83] , and so on), and coherent L1 2 [84][85][86][87][88][89] .…”

Section: Am Of Heasmentioning

confidence: 99%

“…As a result, to achieve a good balance between the strength and ductility of HEAs, many researchers are now working on AM-EHEAs containing both FCC and BCC phases. The processibility, microstructure and mechanical properties of EHEAs fabricated through AM methods have been widely studied [68,69,74,91] . Guo et al illustrated that as-printed AlCoCrFeNi 2.1 HEAs exhibited a completely eutectic structure consisting of ultrafine FCC and ordered B2 phases [74] .…”

Section: Am Of Eheasmentioning

confidence: 99%

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New trends in additive manufacturing of high-entropy alloys and alloy design by machine learning: from single-phase to multiphase systems

Zhou¹,

Zhang²,

Wang³

et al. 2022

J Mater Inf

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Alloys with excellent properties are always in significant demand for meeting the severe conditions of industrial applications. However, the design strategies of traditional alloys based on a single principal element have reached their limits in terms of property optimization. The concept of high-entropy alloys (HEAs) provides a new design strategy based on multicomponent elements, which may overcome the bottleneck problems that exist in traditional alloys. To further maximize the capability of HEAs, a novel additive manufacturing (AM) technique has been utilized to produce HEA components with the desired structures and properties. This review considers a new trend in the AM of HEAs, i.e., from the AM of single-phase HEAs to multiphase HEAs. Although most as-printed single-phase HEAs show superior tensile properties to as-cast ones, their strength is still not satisfactory, especially at elevated temperatures. Thus, multiphase HEAs are developed by introducing hard second phases, such as L12, BCC, carbides, oxides, nitrides, and so on. These phases can be introduced to the matrix using in situ alloying during AM or the subsequent heat treatment. Dislocation strengthening is considered as the main reason for improving the tensile properties of as-printed single-phase HEAs. In contrast, multiple strengthening and toughening mechanisms occur in as-printed multiphase HEAs, which can synergistically enhance their mechanical properties. Furthermore, machine learning provides an effective method to design new alloys with the desired properties and predict the optimal AM parameters for the designed alloys without tedious experiments. The synergistic combination of machine learning and AM will significantly speed up scientific advances and promote industrial applications.

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Section: Am Of Eheasmentioning

confidence: 80%

Section: Key Issues For Hea Design and Ammentioning

confidence: 99%

Section: Am Of Heasmentioning

confidence: 99%

Section: Am Of Heasmentioning

confidence: 99%

Section: Am Of Eheasmentioning

confidence: 99%

See 3 more Smart Citations

New trends in additive manufacturing of high-entropy alloys and alloy design by machine learning: from single-phase to multiphase systems

Zhou¹,

Zhang²,

Wang³

et al. 2022

J Mater Inf

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Strong‐Yet‐Ductile Eutectic Alloys Employing Cocoon‐Like Nanometer‐Sized Dislocation Cells

Shi,

Li,

Jiang

et al. 2024

Advanced Materials

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Eutectic alloys (EAs) with superior fluidity are known to be the easiest to cast into high‐quality ingots, making them the alloys of choice for making large‐sized structural parts. However, conventional EAs (CEAs) have never reached strength–ductility combinations on par with the best in other alloy categories. Via thermomechanical processing of cast Ni‐32.88wt%Fe‐9.53wt%Al CEAs, a cocoon‐like nano‐meshed (as fine as 26 nm) network of dislocations (CNN‐D) is produced via recovery annealing, through the rearrangement of cold‐work‐accumulated dislocations anchored by dense pre‐existing nanoprecipitates. In lieu of traditional plasticity mechanisms, such as TWIP and TRIP, the CNN‐D is particularly effective in eutectic lamellae with alternating phases, as it instigates nanometer‐spaced planar slip bands that not only dynamically refine the microstructure but also transmit from the FCC (face‐centered‐cubic) layers into the otherwise brittle B2 layers. These additional mechanisms for strengthening and strain hardening sustain stable tensile flow, resulting in a striking elevation of both strength and ductility to outrank not only all previous CEAs, but also the state of the art—additively manufactured eutectic high‐entropy alloys. The CNN‐D thus adds a novel microstructural strategy for performance enhancement, especially for compositionally complex alloys that increasingly make use of nanoprecipitates or local chemical order.

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Exploration of a new AlCoCrNiNb high-entropy alloy: in situ alloying of a CoCrMo, M247, and Nb powder mixture via laser powder bed fusion

Tsai,

Cheng,

et al. 2024

Prog Addit Manuf

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High-entropy alloys (HEAs) have compelling advantages, such as high strength and corrosion resistance, but they remain underexplored owing to the limited availability of certain prealloyed and elemental powders. In this study, an AlCoCrNiNb HEA was fabricated in situ via laser powder bed fusion (LPBF) using a powder mixture of commercial CoCrMo, Mar M247, and Nb elemental powders. The powder mixture was blended for 24 h using a horizontal blending machine, to obtain similar chemical compositions in the middle and top layers of the blended powder. However, local Nb aggregation was observed in the bottom layer owing to the particle-size effect. X-ray diffraction and chemical composition analyses revealed that the in situ alloyed AlCoCrNiNb HEA specimen obtained via LPBF was a homogeneous solid solution with a face-centered cubic structure. HEA exhibits a fine-grained morphology, and its maximum microhardness is approximately 970 HV. These characteristics are typical of rapid solidification and sluggish diffusion. These results underscore the effectiveness of using commercial prealloyed and elemental powders for fabricating AlCoCrNiNb HEAs through LPBF-based in situ alloying, thus advancing the development of HEAs. Thermodynamic calculations were performed to support these outcomes.

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Selective laser melting of dense and crack-free AlCoCrFeNi2.1 eutectic high entropy alloy: Synergizing strength and ductility

Cited by 62 publications

References 63 publications

New trends in additive manufacturing of high-entropy alloys and alloy design by machine learning: from single-phase to multiphase systems

New trends in additive manufacturing of high-entropy alloys and alloy design by machine learning: from single-phase to multiphase systems

Strong‐Yet‐Ductile Eutectic Alloys Employing Cocoon‐Like Nanometer‐Sized Dislocation Cells

Exploration of a new AlCoCrNiNb high-entropy alloy: in situ alloying of a CoCrMo, M247, and Nb powder mixture via laser powder bed fusion

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