Ultrafine Lamellar Structure Research Articles

Unveiling exotic multi-scale microstructure transformation and crack formation mechanisms in eutectic ceramic composite by laser powder bed fusion

Laser powder bed fusion (LPBF) represents an advanced and versatile technology. Exploiting its distinctive advantages for direct and rapid fabrication of complex-structured melt-grown oxide eutectic ceramic composite represents a pioneering yet challenging endeavor. In this work, LPBF is creatively employed to fabricate turbine blade-shaped, in-situ ternary eutectic ceramic composite. Through the integration of experimental procedures, Finite element method (FEM) simulations, and numerical analyses, an innovative design and manufacturing of oxide eutectic ceramic composites have been successfully established. Comprehensive FEM simulations, with detailed interface characteristic analysis, have revealed macro-scale cracks induced by intense maximum principal stress, and micro-cracks stemming from significant interfacial energy disparities among the three constituent phases. The applications of rapid solidification and nucleation theories have facilitated profound insights into the formation mechanisms of multi-scale exotic microstructures, including top-layer coarse dendrites, rosette-like spherical internally grown eutectic colony within layers, and columnar eutectic colonies with ultra-fine lamellar eutectic structures. Micro-mechanical property testing reveals enhanced performance in the inter-layer ultra-fine lamellar eutectic structure, which is attributed to a refined eutectic spacing of approximately 61 nm, coupled with distinct and robust bonding interfaces. These groundbreaking achievements, focusing on the processing-microstructure-property relationship in the fabrication of gas turbine blade-shaped solidified eutectic ceramic composite using LPBF, provide invaluable theoretical insights and data. This knowledge is crucial for the LPBF production of high-temperature structural materials, highlighting its significant potential applications in fields of aerospace and mechanical engineering.

Characterization of microstructural evolution pattern toward nano-scale in commercial-purity titanium by incremental sheet forming

In the present investigation, a commercial-purity titanium sheet was formed by a flexible sheet metal forming method, incremental sheet forming (ISF), to investigate its microstructure evolution. The deformation microstructures across the wall of formed parts were systematically examined by optical microscopy (OM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and high resolution TEM (HRTEM). Microstructural evolution from millimeter- to nano-scale was explored, with special attention paid to the refinement below 100 nm. A general pattern of structural evolution begins with the formation of uni- and multi-directional twins, which is accompanied by the initiation and development of ultrafine lamellar structure and final evolution of nano-lamellar structure and nano-equiaxed structure. A twinning-dominated process that was supplemented with dislocation slip-dominated one governed the microstructural evolution toward nano-regime. The strain-induced evolution of nano-lamellar and nano-equiaxed structures were discussed, of which the underlying refinement mechanism was analyzed. This technique was promising to offer an optional route for realizing the strengthening of metal parts via synthesizing nanostructures, showing potential scientific and technological importance in fabricating the high-strength metal formed productions for further meeting industrial applications.

Achieving ultrafine lamellar structure and exceptional electrochemical properties of Fe35Mn27Ni28Co5Cr5 high-entropy alloy through severe cold rolling process

This research provides an insight into the effect of ultrafine lamellar microstructures on the electrochemical behavior of Fe35Mn27Ni28Co5Cr5 high-entropy alloys (HEAs) in a 0.5 M H2SO4 solution. Following the severe cold rolling (SCR) process at a reduction rate of 90 %, the Fe35Mn27Ni28Co5Cr5 alloy exhibited a predominantly lamellar microstructure aligned along the rolling direction, leading to variations in grain size and subsequent differences in electrochemical behaviors. The potentiodynamic polarization (PDP) plots and electrochemical impedance spectroscopy (EIS) measurements confirmed that the influence of heavy cold rolling on corrosion resistance was mainly attributed to grain refinement and residual stress. The corrosion resistance of HEAs was ameliorated as a result of increased rolling deformation. The 90 % cold-rolled specimen showed excellent comprehensive corrosion resistance, for which the Ecorr and icorr values were found to be −0.278 V and 329 µA/cm2. Consequently, the development of ultrafine lamellar structures provides better conditions for forming passive films with higher protection behavior compared with their other counterparts. It could be due to the improved surface conditions for the development of oxide films resulting from higher homogeneity. The present work will provide new opportunities for tailoring the electrochemical characteristics of HEAs with strong commercial viability.

Experimental and numerical investigation of the yield point phenomenon and strain partitioning behavior in a dual-phase steel with lamellar structure

Severe rolling techniques show potential for enhancing the strength and ductility of metallic materials, but the resulting microstructural anisotropy affects the mechanical behavior. The study investigated the anisotropic yield point phenomenon (YPP) and strain partitioning behavior in a dual-phase steel with ultrafine lamellar structure, fabricated through severe cold- and warm-rolling procedures. Experimental results show that tensile specimens aligned parallel to the rolling direction exhibit YPP and higher ductility, while those oriented normal to the rolling direction show continuous yielding behavior and decreased ductility. Using Digital Image Correlation techniques, we studied the evolution of the strain distribution on the surface of the gauge segment, revealing that the strain within the Lüders band was almost constant during the Lüders band propagation. Strain-induced martensitic transformation (SIMT) was observed within the Lüders band and the volume fraction of martensite keeps almost constant during the Lüders band propagation. Numerically, we integrated the mechanisms of SIMT and YPP into a dislocation density-based J2 plasticity constitutive framework. Simulated tensile tests indicate a smaller Lüders strain resulted from the initial higher strain hardening rate. Additionally, SIMT suppresses local instability and therefore promotes the stable propagation of Lüders bands. Simulations verify that the lamellar orientation and SIMT significantly affect the strain hardening rate and void growth. Our findings provided a new perspective on the intrinsic mechanism of the anisotropic YPP and ductility in lamellar dual-phase steels.

Low-dislocation-density ultrafine lamellar structure buffering triples ductility in Cu-8wt.%Sn alloy treated by rotary swaging and appropriate annealing

Breaking the strength-ductility trade-off in metal materials has always been a prominent topic in materials science. Here, we proposed a novel strategy of combining rotary swaging (RS) with appropriate annealing to construct an ultrafine lamellar structure with low dislocation density in Cu-8wt.% Sn alloy. This unique anisotropic structure achieves triple ductility without compromising strength compared with the traditional cold rolling process. Results show that the lamellar structure composed of alternating ultrafine-grained α-Cu and brittle Sn-rich phases can be significantly refined by RS, which can weaken stress concentration and thus reduce microcrack nucleation during tensile deformation. The lamellar ultrafine-grained α-Cu with low dislocation density has excellent strain hardening ability, which can effectively mediate deformation, and resist crack propagation and coalescence, thereby enhancing the ductility of materials. As a deformation method with industrial application capability, RS can construct a novel lamellar structure to overcome the strength-ductility dilemma, which deserves attention in materials science.

Enhancing the strength and conductivity of commercialized Cu-Cr-Zr plate through simple high strain cold rolling and aging

Plastic deformation usually improves the strength of Cu alloys by introducing high density dislocations and refined grains, but inevitably reducing electrical conductivity and ductility. Here we demonstrate that three exclusive properties, i.e., strength, conductivity, and ductility can be simultaneously enhanced in commercialized Cu-Cr-Zr plates through the well-controlled thermomechanical treatment. Very high strain cold rolling with a thickness reduction of 98% is applied, resulting in the formation of ultra-fine lamellar structures with an average size of 146 nm, which contributes to high tensile strength of 643 MPa. However, the elongation and electrical properties are poor. The subsequent aging treatment at a low temperature of 400 °C for 5 h introduces high density coherent Cr precipitates in those lamellar structures, while keeping the lamellar thickness almost unchanged. The aged Cu-Cr-Zr alloy exhibit high strength of 592 MPa, high conductivity of 86.8% IACS, and adequate elongation of 15.5%. This work proposes a strategy of overcoming the strength-ductility and strength-conductivity trade-off relationships in industrial Cu products through the balanced manipulation of grain morphology and grain interior precipitation.

Dynamic thermomechanical response and constitutive modeling of eutectic high-entropy alloy

Since the eutectic high-entropy alloys (EHEAs) have been expected to be candidates for superalloys at the beginning of their invention, getting insights into their high-temperature mechanical performance under impact loadings is of particular significance for exploring their application potential in extreme service environments with high temperature and high strain rate. Meanwhile, additive manufacturing methods have been found to be very suitable for preparing EHEAs in the past two or three years. Therefore, this work, as the first attempt, carries out a comparative study on the microstructural and dynamic thermomechanical performances of the Ni32Co30Cr10Fe10Al18 (Ni32Al18) EHEA manufactured by the laser metal deposition (LMD) and arc melting. The uniaxial compressive responses are tested over a strain rate range of 0.001/s∼7000/s and a temperature range of 77 K∼1123 K. The difference in microstructures and plastic flow behaviors between the LMD and the arc melted samples are revealed. The results show that the LMD samples feature a combination of the primary FCC phases and the typical lamellar eutectic structures, while the arc melted samples possess only ultrafine lamellar eutectic structures. The LMD samples exhibit lower strength and higher ductility than the arc melted ones. The high strength in the arc melted samples is attributed to the high athermal resistance of the dense lamellar structures (composed of ultrafine FCC and B2 phases) to mobile dislocations, while the primary FCC phases lead to high ductility and strain hardening ability in the LMD samples. The anisotropy in flow stress of the LMD sample is found at each strain rate and attributed to the different phase boundary densities generated by the LMD route in different directions. Then, a viscoplastic constitutive model considering the microstructural features is developed, which can reflect the size effect of grains and phases on flow stress, as well as the influence of the phase content on the rate-temperature coupling effect. This model is demonstrated to successfully predict the dynamic plastic flow behavior of both the LMD and arc melted Ni32Al18 EHEA over a wide range of temperature. Furthermore, the Ni32Al18 EHEA is found to have superior high-temperature dynamic specific yield strength compared to several existing typical superalloys.

Strain gradient induced grain refinement far below the size limit in a low carbon hypoeutectoid steel (0.19 wt% C) via pipe inner surface grinding treatment

A low carbon hypoeutectoid steel (0.19 wt% C) with proeutectoid ferrite and pearlite dual-components was subjected to surface plastic deformation via pipe inner surface grinding (PISG) at room temperature. The deformation microstructures for each component were systematically characterized along depth, and the patterns of structural evolution toward nanometer regime as well as the governing parameters were addressed. Proeutectoid ferrite grains were refined down to 17 nm, and the pattern covering a length scale of 4–5 orders of magnitude from micron- to nanometer-scale follows: formation of cellular dislocation structure (CDS), elongated dislocation structure (EDS), ultrafine lamellar structure (UFL) and finally the nanolaminated structure (NL). The pearlite experiences the deformation and refinement, and finally the transforming the ultrafine pearlite (UFP) into nanolaminated pearlite (NLP) with the ferrite lamellae as thin as 20 nm. Refinement for both UFL (UFP) and NL (NLP) can be realized via forming novel extended boundaries within ferrite lamellae. A critical lattice curvature of ∼2.8° is required for forming such extended boundary, corresponding to a minimum strain gradient of 0.25 μm−1 for a 100 nm-thick lamella. Refinement below size limit (expressed by lamellar thickness dT in nm) is correlated with the strain gradient (χ, in μm−1) by: dT=12.5χ. Refinement contributions from strain gradient caused by PISG processing and material heterogeneity were discussed.

Ultrafine lamellar structure AM60B magnesium alloy sheet prepared by high strain rate rolling

The rolled sheet was successfully prepared for the as-cast AM60B magnesium alloy by using the high strain rate rolling (HSRR) in the temperature range of 310 °C – 370 °C. An ultrafine lamellar structure consisting of small angle grain boundaries was developed in the HSRRed sheet by the detwinning of high-density twins. The ultrafine lamellar structure was characterized by means of the high-resolution transmission electron microscopy technique, and the effect of temperature on the detwinning was analyzed. Furthermore, the morphological difference of the ultrafine lamellar structure and its effect on the mechanical properties of the rolled sheet were investigated. The results show that the dislocation motion, cross twinning, dynamic recovery and dynamic recrystallization have multiple interactions with the detwinning behavior in different modes. And the degree of detwinning and the post-rolling microstructure are greatly affected by the interaction. Dynamic precipitation of the second phase is induced by the HSRR process at 370 °C. Nano particles precipitate along twin grain boundaries and form the ‘precipitation band’. However, the detwinning is not affected by the ‘precipitation band’. In addition, it is also revealed from the results that a uniform and fine fully-lamellar structure is developed as the HSRR process is conducted at a medium temperature of 340 °C. Meanwhile, the alloy rolled at 340 °C has relatively optimal mechanical properties, and the strength and ductility are well balanced.

Strain-dependence of deformation microstructures in ultra-low-C IF steel deformed to high strains by torsion at elevated temperatures

Single-phase bcc-ferrite in an interstitial free (IF) steel was deformed to different strains in a wide range from low to high strains ( ε = 1–7) by torsion under different Zener-Hollomon ( Z ) conditions. The specimens were rapidly quenched after the torsion to preserve microstructures formed under different deformation conditions. The results showed that during high-Z (low-temperature) deformation, grains were subdivided by geometrically necessary boundaries (GNBs) via the grain subdivision mechanism. Deformation to high strains ( ε > 5) led to the ultrafine lamellar structures (with grain sizes < 1 μm) mainly composed of GNBs having high misorientation angles. Decreasing Z with increasing temperature and/or decreasing strain rate accelerated thermally activated processes, such as dynamic recovery and boundary migration. Unlike the ultrafine lamella formed under the high- Z condition, a variety of microstructures having equiaxed morphologies with fine to coarse grain sizes (>1 μm) were realized with decreasing Z . The significance of the grain subdivision and the thermally activated phenomena on the formation of various microstructures under different deformation conditions is discussed.

Non-conventional transformation pathways and ultrafine lamellar structures in γ-TiAl alloys

The mechanical properties of two-phase γ-TiAl alloys depend strongly on the scale of their lamellar microstructures. In this study, we investigate the effect of alloy composition on lamellar thickness in Ti100-xAlx by simulating microstructural evolution during the α2′ → α2 + γ phase transformation using the phase field method. From both existing experimental data and our simulation results we find that the average thickness of γ lamellae first decreases and then increases with increasing Al content. Further analyses reveal that this unique composition-dependence of the lamellar thickness could be associated with non-conventional pseudospinodal decomposition and congruent structural transformation mechanisms that generate ultra-high densities of nuclei at the initial stage, which impacts the later growth processes. The interplay between the number density of nuclei and the number of coalescence events during growth results in the non-monotonic dependence of the lamellar thickness on the alloy composition. These findings may offer new insights on the design of ultrafine lamellar microstructures for γ-TiAl alloys.

An ultrahigh-strength steel produced by heavy warm rolling of the metastable austenite

An ultrahigh-strength steel with sufficient uniform elongation (UE) and high strain-hardening ability was fabricated by a combination method of heavy warm rolling (HWR) on the metastable austenite and subsequent quenching (Q). The WR-Qed steel shows an ultra-fine martensitic structure with an average effective grain size (EGS) of 0.57 μm, yield strength (YS) of 1911 MPa and ultimate tensile strength (UTS) of 2411 MPa. The tempering (T) effect on microstructure and properties of the steel was investigated. Compared with the heavily hot-rolled and tempered steel, the WR-QTed steels exhibited substantial enhancement in strength, ductility and strain-hardening ability. After tempering at 200 ℃ for 1 h, the WRed steel demonstrated an excellent strength-ductility combination with a YS of 1905 MPa, UTS of 2163 MPa and total elongation of 11.7%. Grain refinement and dislocation strengthening play major roles in enhancing strength. It is believed that the heavy warm deformation can effectively refine the metastable austenite grains and consequently result in the ultrafine-structured steel by martensitic transformation during the subsequent quenching. The excellent strength-ductility combinations of the WR-Qed steel are also closely associated with effect of ultrafine lamellar structures of martensite, nano-twins and high density low-angle grain boundaries.

Use of reactive nanostructured chemicals for refinement of Si eutectic in an aluminum casting alloy

Trisilanol phenyl polyhedral silsesquioxane (phenyl TSP) was added to a commercial aluminum alloy, AlSi10MnMg, to investigate its influence on microstructure, mechanical properties, and solidification behavior. Addition of phenyl TSP was successful in refining the morphology of the eutectic Si into an ultrafine lamellar structure. Furthermore, this refined as-cast morphology can be obtained even when the molten aluminum alloy was held for 96 h in a furnace set at around 1000 K. This no fading phenomenon is of a significant processing benefit to the current use of Sr for refining the eutectic morphology. The ductility of phenyl TSP-refined AlSi10MnMg alloy was consistent with Sr-modified alloy at room, 423 K, and 573 K elevated temperature while maintaining similar strength. Cooling curve analysis showed the Al–Si eutectic arrest temperatures during solidification were decreased with the phenyl TSP addition, suggesting phenyl TSP bonds with Al to slow down the Al segregation from Al–Si melt during the eutectic reaction, leading to the microstructural refinement of Al–Si eutectic.

High strength and ductility of electron beam melted β stabilized γ-TiAl alloy at 800°C

A nearly fully dense β stabilized γ-TiAl alloy was additively manufactured by electron beam melting. The as-fabricated specimen exhibited a fine structure consisting of α2/γ colonies (<5 μm), equiaxed γ (1 μm) and βo (<1 μm) grains. The unique microstructure rendered high strength (580 MPa) and high ductility (>50%) in the sample at 800 °C. Annealing and subsequent stabilization treatments resulted in α2/γ colonies (<50 μm) with an ultrafine (20–40 nm) lamellar structure, which gave rise to high strength (770 MPa) and good ductility (6%) levels superior to those of conventional counterparts and other γ-TiAl alloys at 800 °C.

Nucleation and epitaxial growth of highly textured Al2O3–ZrO2 nanoeutectic rapidly solidified from oxyacetylene flame remelting

The nucleation and epitaxial growth behavior of a novel Al2O3-ZrO2 nanoeutectic rapidly solidified from the oxyacetylene flame remelting have been investigated. The nanoeutectic ceramic consists mainly of highly textured cellular structure with an average interphase spacing of 136 nm. Especially, a singular transition mechanism associated with “one-step cellular refining” to “two-step cellular refining” is proposed in a variable region from a coarse irregular to an ultrafine lamellar structure, and the regional undercooling is estimated to be 0.57–2.86 K. The Al2O3 phase nucleates as the leading phase in the rapidly solidified structure according to a quantitative calculation of nucleation rate. The cellular eutectic exhibits with a tilted feature, where its cellular growth deviates from the heat flow direction to a preferred growth orientation.

Effect of cooling rate on microstructure evolution of Ti-45Al-8.5Nb-0.2W-0.2B-0.02Y alloy during multi-step heat treatment

Microstructure evolution of Ti-45Al-8.5Nb-0.2W-0.2B-0.02Y alloy (at.%) resulted from different cooling rates during the whole phase transformation process has been thoroughly investigated. The results show that the cooling rate during β → α transformation plays a crucial role in the modification of the crystallographic orientation relationship between the α grains and their parent β phase. The decrease of cooling rate can reduce the volume fraction of Burgers α grains and avoid the preferential distribution of lamellar interface traces. This could be attributed to the different nucleation and growth kinetics of α phase affected by the cooling rate. Moreover, the lamellar structure characteristics are closely related to the cooling rate during α → α2 + γ transformation and their responses to stabilization treatment shall vary accordingly. A fast cooling rate retains a high quantity of high temperature α/α2 phase. These α/α2 phase could decompose into ultrafine lamellar structure during subsequent stabilization treatment. While the average lamellar spacing of the slow cooled microstructure has a small increase by limited continuous growth of the pre-existing γ lamellae during stabilization treatment.

Thermal stability of retained austenite and mechanical properties of medium-Mn steel during tempering treatment

The thermal stability of retained austenite (RA) and the mechanical properties of the quenched and intercritical annealed 0.1C-5Mn steel with the starting ultrafine lamellar duplex structure of ferrite and retained austenite during tempering within the range from 200 to 500 °C were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM) and tensile testing. The results showed that there was a slight decrease in the RA volume fraction with increasing tempering temperature up to 400 °C. This caused a slight increase in the ultimate tensile strength (UTS) and a slight decrease in the total elongation (TE); thus, the product of UTS to TE (UTS×TE) as high as 31 GPa • % was obtained and remained nearly unchanged. However, a portion of the RA began to decompose when tempered at 500 °C and thus caused a ∼35% decrease of the RA fraction and a ∼16% decrease of the value of UTS×TE. It is concluded that the ultrafine lamellar duplex structure is rather stable and the excellent combination of strength and ductility could be retained with tempering temperature up to 400 °C. Thus, thermal processes such as galvanization are feasible for the tested steel provided that their temperatures are not higher than 400 °C.

Bimodal titanium alloys with ultrafine lamellar eutectic structure fabricated by semi-solid sintering

We report on a novel approach to synthesize (Ti100-x-yFexCoy)82Nb12.2Al5.8 (at.%) bimodal alloys and provide fundamental insight into their underlying microstructural evolution and mechanical behavior. In our work, a bimodal microstructure is attained via selection of phases and composition in a eutectic reaction followed by semi-solid sintering. Specifically, if one selects an atomic ratio of Ti/Fe corresponding to the eutectic composition, the resultant (Ti63.5Fe26.5Co10)82Nb12.2Al5.8 alloy shows a bimodal microstructure of micron-sized fcc Ti2(Co, Fe) embedded in an ultrafine lamellar eutectic matrix containing ultrafine bcc β-Ti and bcc B2 superstructured Ti(Fe, Co) lamellae. This structure forms from the complete eutectic reaction between β-Ti and Ti(Fe, Co). The phase boundary of β-Ti and Ti(Fe, Co) lamellae consists of a coherent interface with the orientational relationships: (110)β-Ti//(110)Ti(Fe, Co), (200)β-Ti//(100)Ti(Fe, Co) and (11¯0)β-Ti//(11¯0)Ti(Fe,Co). Such bimodal alloy exhibits ultra-high compressive yield strength of 2050 MPa with a compressive plasticity of 19.7%, which exceed published values of equivalent materials. These unusual mechanical properties are attributed to a mechanism that involves blocking, branching and multiplication of β-Ti lamellae, dislocation interactions in Ti(Fe, Co) lamellae, and the stability of coherent interfaces. In addition, unusual phenomenon of introduced high-density dislocations in B2 superstructured Ti(Fe, Co) lamellae, other than β-Ti lamellae, can be rationalized based on the formation and decomposition of superlattice dislocations according to classic crystallographic strengthening theory.

Ultrafine-structured Ni-based bulk alloys with high strength and enhanced ductility

High-strength ultrafine eutectic-dendrite composites were produced from arc-melted ingots of a novel Ni-Hf alloy system. The composites are composed of micron-scale dendritic phases (Ni5Hf intermetallic phase or Ni solid solution) and an ultrafine lamellar eutectic matrix (Ni5Hf + fcc-Ni). The optimization of the Ni-Hf alloy composition is performed from the viewpoint of both high strength and ductility. The strongest Ni90Hf10 has an ultrafine lamellar eutectic structure and exhibits a high strength of 3.56GPa and a plastic deformation of 34% under compression. In particular, the material’s plasticity can be monotonically improved by reinforcing the ductile dendritic phases in the eutectic matrix. The high strength and ductility values can be achieved without using the injection mould casting or rapid solidification procedure. The microstructure–property relationship of these ultrafine-structured composites is also discussed here.

Designing ultrafine lamellar eutectic structure in bimodal titanium alloys by semi-solid sintering

We report on a novel approach to design typical ultrafine lamellar eutectic structure in bimodal alloys fabricated by semi-solid sintering (SSS) of a eutectic mixture. In our work, ultrafine lamellar eutectic structure was implemented by controlling the phase composition of eutectic reaction, and consequently by regulating the structure of eutectic reaction-induced liquid phase through varying component number. Microstructure analysis indicate that although all SSSed alloys have the same three phase constitutions of bcc β-Ti, bcc Ti(Fe, Co), and fcc Ti2(Co, Fe), the morphology and distribution of the eutectic structure transforms from limited length and minor quantity, to partial fine alternating bcc β-Ti and bcc Ti(Fe, Co) lamellae, and further to typical complete ultrafine alternating continuous lamellae in the SSSed ternary Ti-Fe-Co, quaternary Ti-Fe-Co-Nb, and quinary Ti-Fe-Co-Nb-Al alloys. Interestingly, the SSSed Ti-Fe-Co-Nb-Al alloy presents a novel bimodal microstructure of coarse fcc Ti2(Co, Fe) surrounded by an ultrafine lamellar eutectic matrix containing ultrafine bcc β-Ti and bcc Ti(Fe, Co) lamellae. This bimodal microstructure exhibits ultra-high yield strength of 2050 MPa with plasticity in compression of 19.7%, which exceed published values of equivalent materials. Our results provide a novel pathway for fabricating new-structure metallic alloys for high-performance structural applications.