Tuning microstructure and mechanical properties of open porous TiNb and TiFe alloys by optimization of dealloying parameters

Okulov, Ilya; Okulov, Artem; Волегов, А. С.; Markmann, Jürgen

doi:10.1016/j.scriptamat.2018.05.029

Cited by 52 publications

(37 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although there are some disparities between the current study and the literature due to different materials and experimental conditions, the role of outstanding stability of the 3DNP HEA is considered more important when assessing its physical properties in view of coarsening. Compared with general pure metals or binary alloys, 3DNP HEA shows a much slower coarsening rate and loss of desired 3DNP structure, thus, the porous structure of 3DNP HEA remains in the nanoscale regime after the same heat treatment. Consequently, the outstanding yield strength of ligaments in 3DNP HEA remains close to the theoretical strength ( G /2π) after the subjection to elevated temperature.…”

mentioning

confidence: 99%

Beating Thermal Coarsening in Nanoporous Materials via High‐Entropy Design

et al. 2019

View full text Add to dashboard Cite

produced by dealloying have outstanding physical properties due to their unique structure with open porous networks, [3][4][5] the undesirable coarsening phenomenon leads to degradation of physical properties over time, even at room temperature. [6][7][8] The originally proposed idea behind high-entropy alloy (HEA) with multiprinciple elements is maximizing the configuration entropy to stabilize a solid-solution alloy without undesired ordered intermetallics. [9][10][11] Many studies have suggested that HEAs uniquely possesses combined desirable properties such as a high strength and ductility paired with high fracture toughness, [12][13][14] fatigue resistance, [15] and creep resistance. [16] HEAs also show promising properties in harsh environments resisting corrosion, [17][18][19] and irradiation [20] attacks. Atomic size differences between constituting elements in HEA increase the activation energy for grain growth, and sluggish diffusion kinetics has considered as the main reason for the exceptional high strength and structural stability of HEAs at high temperatures. [21,22] The rationale behind it, the multiprinciple elements cause larger fluctuations in lattice potential energy (LPE), providing many low-LPE sites that hinder atomic diffusion. [23] Grain growth and ligament coarsening rely on the same physical background of surface diffusion. In that context, the high-entropy design in nanoporous materials has a potential for achieving an exceptional stability against the coarsening.Controlling the feature sizes of 3D bicontinuous nanoporous (3DNP) materials is essential for their advanced applications in catalysis, sensing, energy systems, etc., requiring high specific surface area. However, the intrinsic coarsening of nanoporous materials naturally reduces their surface energy leading to the deterioration of physical properties over time, even at ambient temperatures. A novel 3DNP material beating the universal relationship of thermal coarsening is reported via high-entropy alloy (HEA) design. In newly developed TiVNbMoTa 3DNP HEAs, the nanoporous structure is constructed by very fine nanoscale ligaments of a solid-solution phase due to enhanced phase stability by maximizing the configuration entropy and suppressed surface diffusion. The smallest size of 3DNP HEA synthesized at 873 K is about 10 nm, which is one order of magnitude smaller than that of conventional porous materials. More importantly, the yield strength of ligament in 3DNP HEA approaches its theoretical strength of G/2π of the corresponding HEA alloy even after thermal exposure. This finding signifies the key benefit of high-entropy design in nanoporous materials-exceptional stability of size-related physical properties. This high-entropy strategy should thus open new opportunities for developing ultrastable nanomaterials against its environment.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.

show abstract

mentioning

confidence: 99%

Beating Thermal Coarsening in Nanoporous Materials via High‐Entropy Design

et al. 2019

View full text Add to dashboard Cite

show abstract

“…However, if there were Ti-Al powders employed in the starting mixing as Ti-Al(2), the location of the phases rich in Al was not appreciated (Figure 2e). Although, in the bibliography has been reported the formation of new phases due to the liquid metal dealloying reaction [33,34], in this specimen fabricated at this temperature, it seems that no intermetallics were in situ formed, having the aluminium in solid solution with the titanium matrix. These observations were verified by the XRD analysis.…”

Section: Microstructural Study and Xrd Analysismentioning

confidence: 67%

“…dealloying reaction [33,34], in this specimen fabricated at this temperature, it seems that no intermetallics were in situ formed, having the aluminium in solid solution with the titanium matrix. These observations were verified by the XRD analysis.…”

Section: Microstructural Study and Xrd Analysismentioning

confidence: 73%

Reaction Layer Analysis of In Situ Reinforced Titanium Composites: Influence of the Starting Material Composition on the Mechanical Properties

Montealegre-Meléndez

Arévalo

Beltrán

et al. 2020

Metals

View full text Add to dashboard Cite

This study aims at the analysis of the reaction layer between titanium matrices and reinforcements: B 4 C particles and/or intermetallic Ti x Al y . Likewise, the importance of these reactions was observed; this was particularly noteworthy as regard coherence with the obtained results and the parameters tested. Accordingly, five starting material compositions were studied under identical processing parameters via inductive hot pressing at 1100 • C for 5 min in vacuum conditions. The results revealed how the intermetallics limited the formation of secondary phases (TiC and TiB) created from the B and C source. In this respect, the percentages of TiB and TiC slightly varied when the intermetallic was included in the matrix as prealloyed particles. On the contrary, if the intermetallics appeared in situ by the addition of Ti-Al powder in the starting blend, their content was lesser. The mechanical properties values and the tribology behaviour might deviate, depending on the percentage of the secondary phases formed and its distribution in the matrix.

show abstract

“…Therefore, it is necessary to reduce the grain sizes of metastable β titanium alloys and restrict their growth. In order to overcome the drawback, lots of studies about beta-titanium alloys reinforced by intermetallic particles (or eutectic structures) were carried out [5][6][7][8][9][10][11][12]. The Ni and Co elements were partially segregated to the interdendritic region to form TiNi and TiCo intermetallic phases, resulting in fine interdendritic precipitates or eutectic structures to obtain high strength [5][6][7]13].…”

Section: Introductionmentioning

confidence: 99%

Grain Refinement of Ti-15Mo-3Al-2.7Nb-0.2Si Alloy with the Rotation of TiB Whiskers by Powder Metallurgy and Canned Hot Extrusion

Hou

Gao

Cui

et al. 2020

Metals

View full text Add to dashboard Cite

In situ synthesized TiB whiskers (TiBw) reinforced Ti-15Mo-3Al-2.7Nb-0.2Si alloys were successfully manufactured by pre-sintering and canned hot extrusion via adding TiB2 powders. During pre-sintering, most TiB2 were reacted with Ti atoms to produce TiB. During extrusion, the continuous dynamic recrystallization (CDRX) of β grains was promoted with the rotation of TiBw, and CDRXed grains were strongly inhibited by TiBw with hindering dislocation motion. Eventually, the grain sizes of composites decreased obviously. Furthermore, the stress transmitted from the matrix to TiBw for strengthening in a tensile test, besides grain refinement. Meanwhile, the fractured TiBw and microcracks around them contributed to fracturing.

show abstract

Tuning microstructure and mechanical properties of open porous TiNb and TiFe alloys by optimization of dealloying parameters

Cited by 52 publications

References 32 publications

Beating Thermal Coarsening in Nanoporous Materials via High‐Entropy Design

Beating Thermal Coarsening in Nanoporous Materials via High‐Entropy Design

Reaction Layer Analysis of In Situ Reinforced Titanium Composites: Influence of the Starting Material Composition on the Mechanical Properties

Grain Refinement of Ti-15Mo-3Al-2.7Nb-0.2Si Alloy with the Rotation of TiB Whiskers by Powder Metallurgy and Canned Hot Extrusion

Contact Info

Product

Resources

About