Microstructures and high temperature oxidation behaviors of AlMo0.5NbTa0.5TiZr high entropy alloys coated by silicon pack cementation

Hwang, Cheol Hong; Shinde, K.P.; Oh, Jinkeun; Lee, S.; Chung, Choong‐Heui; Park, J.S.

doi:10.1016/j.corsci.2023.111203

Cited by 12 publications

(3 citation statements)

References 35 publications

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“…[ 26 , 27 ] Coating with stable oxide formers (e.g., Al, Si, and Cr) is often used to improve the oxidation resistance of alloys: for example, Saad et al. coated Hf 0.5 Nb 0.5 Ta 0.5 Ti 1.5 Zr with an aluminide layer, which prevented the pesting behavior (disintegration into powders) when exposed to air at 800 °C for 5 h. [ 28 ] To our knowledge, silicide coatings have not been studied for equiatomic HfNbTaTiZr, but they have been used to coat MoNbTaW, [ 29 ] MoNbTaVW, [ 30 ] and AlMo 0.5 NbTa 0.5 TiZr [ 31 ] ; they have the advantage of forming a dense SiO 2 ‐rich scale during oxidation, which can flow and heal cracks at elevated temperatures. [ 30 ]…”

Section: Introductionmentioning

confidence: 99%

Ink‐Extrusion 3D Printing and Silicide Coating of HfNbTaTiZr Refractory High‐Entropy Alloy for Extreme Temperature Applications

Zhang,

Hsu,

Dunand

2024

Advanced Science

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An oxygen‐resistant refractory high‐entropy alloy is synthesized in microlattice or bulk form by 3D ink‐extrusion printing, interdiffusion, and silicide coating. Additive manufacturing of equiatomic HfNbTaTiZr is implemented by extruding inks containing hydride powders, de‐binding under H2, and sintering under vacuum. The sequential decomposition of hydride powders (HfH2+NbH+TaH0.5+TiH2+ZrH2) is followed by in situ X‐ray diffraction. Upon sintering at 1400 °C for 18 h, a nearly fully densified, equiatomic HfNbTaTiZr alloy is synthesized; on slow cooling, both α‐HCP and β‐BCC phases are formed, but on quenching, a metastable single β‐BCC phase is obtained. Printed and sintered HfNbTaTiZr alloys with ≈1 wt.% O shows excellent mechanical properties at high temperatures. Oxidation resistance is achieved by silicide coating via pack cementation. A small‐size lattice‐core sandwich is fabricated and tested with high‐temperature flames to demonstrate the versatility of this sequential approach (printing, sintering, and siliconizing) for high‐temperature, high‐stress applications of refractory high‐entropy alloys.

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Section: Introductionmentioning

confidence: 99%

Ink‐Extrusion 3D Printing and Silicide Coating of HfNbTaTiZr Refractory High‐Entropy Alloy for Extreme Temperature Applications

Zhang,

Hsu,

Dunand

2024

Advanced Science

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“…Nanoscale non-active surface coatings can be an effective barrier to physically isolate the metal matrix from its surrounding media, thereby improving the surface properties of metals [6]. Therefore, extensive research has been focused on developing the surface coating technologies, including vapor deposition, spray coating, and plasma electrolytic oxidation, to introduce coating materials on metal surfaces [12][13][14][15][16]. Besides, the effectiveness of corrosion/oxidation protection of surface coatings is found to be related to their chemical composition, thickness, and adhesion strength with metal matrix [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

“…Bulk metal surfaces generally exhibit {001} orientation and are accompanied by complex low surface energy facets (surface islands or steps) after heat treatment, due to the synergetic effect of ω and . γ (Figure 1a) [12][13][14][15]. Since ω is an intrinsic parameter that is determined by the biaxial modulus, tailoring .…”

Section: Introductionmentioning

confidence: 99%

Reorientation Mechanisms of Graphene Coated Copper {001} Surfaces

Song

Yao

et al. 2023

Metals

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Engineering the surface orientation of face-centered cubic (fcc) metals to the close-packed {111} plane can significantly enhance their oxidation resistance. However, owing to the synergetic effect of surface energy density (γ˙) and strain energy density (ω), such close-packed surface orientation can currently only be achieved by atomic-level thin film epitaxy or monocrystallization of polycrystalline metals. In this study, we characterized the microstructures of pure copper (Cu) foil and two types of graphene-coated Cu (Gr/Cu) foils and observed a 12~14 nm thick reconstructed surface layer with the {111} orientation in the high-temperature deposited Gr/{001} Cu surface. Combining the statistical results with thermodynamic analysis, we proposed a surface melting-solidification mechanism for the reconstruction of the Cu surface from {001} orientation to {111} orientation. This process is dominated by Gr/Cu interfacial energy and is particularly promoted by high-temperature surface melting. We also validated such a mechanism by examining Cu surfaces coated by h-BN (hexagonal boron nitride) and amorphous carbon. Our findings suggest a possible strategy to enhance the surface properties of fcc metals via engineering surface crystallography.

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Improving oxygen resistance of hydrogen storage alloys with graphite or nickel coating

Xu,

Cheng,

Zhao

et al. 2024

International Journal of Hydrogen Energy

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Microstructures and high temperature oxidation behaviors of AlMo0.5NbTa0.5TiZr high entropy alloys coated by silicon pack cementation

Cited by 12 publications

References 35 publications

Ink‐Extrusion 3D Printing and Silicide Coating of HfNbTaTiZr Refractory High‐Entropy Alloy for Extreme Temperature Applications

Ink‐Extrusion 3D Printing and Silicide Coating of HfNbTaTiZr Refractory High‐Entropy Alloy for Extreme Temperature Applications

Reorientation Mechanisms of Graphene Coated Copper {001} Surfaces

Improving oxygen resistance of hydrogen storage alloys with graphite or nickel coating

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