Solid Solution Hardening Research Articles

Review — Research and Development of Titanium-Containing Biomedical High Entropy Alloys (BioHEAs) Utilizing Rapid Solidification via Laser-Powder Bed Fusion

High entropy alloys (HEAs) have been developed as a new class of structural materials that consist of multicomponent elements with an approximately equiatomic ratio for increasing the mixing entropy to stabilize the solid solution phase. HEA for biomedical applications (BioHEA) was first developed in Japan; HEA comprising nonbiotoxic elements was specifically designed, demonstrating excellent mechanical properties and biocompatibility. However, elemental segregation, often observed in BioHEAs, hinders the inherent functions derived from high entropy effects and solid solution hardening. In this review article, elemental homogenization and functionalization of BioHEAs utilized by ultra-rapid cooling via laser-powder bed fusion and the characteristics of these BioHEAs, especially focusing on their excellent properties for biomedical applications, are introduced.

Development of Ternary Ti-Ag-Cu Alloys with Excellent Mechanical Properties and Antibiofilm Activity.

Titanium-20 mass% Silver (Ti-20%Ag) alloy can suppress biofilm formation on the surface. Unlike bactericidal agents, it does not kill bacteria; therefore, the healthy oral microflora remains undisturbed. To utilize the unique functions of this alloy and enable its use in the fabrication of dental prostheses that require relatively high strength, we added copper (Cu) as an alloying element to improve strength. This study aimed to develop ternary Ti-Ag-Cu alloys with excellent mechanical properties and antibiofilm activity. As a result of investigating the mechanical properties of several experimental alloys, the tensile strength, yield strength, and hardness of Ti-20%Ag-1%Cu and Ti-20%Ag-2%Cu alloys were improved by the solid-solution strengthening or hardening of the αTi phase. In addition, these alloys had the same ability to suppress biofilm formation as the Ti-20Ag alloy. Thus, Ti-20%Ag-1-2%Cu alloys can be used for fabrication of narrow-diameter dental implants and prostheses subjected to extremely high force, and these prostheses are useful in preventing post-treatment oral diseases.

Comparative evaluation of the yield strength of ferrite-pearlite steels by structure parameters

The influence of different hardening mechanisms on the yield strength of carbon and low-alloy steels is studied. It is established that for Ст.5пс hot-rolled steel, the greatest influence on the yield strength is exerted by solid-solution and grain-boundary hardening, and for 16Г2АФ low-alloyed steel, in addition to these types of hardening, it is also dispersion type. It is shown that thermomechanical treatment of Ст.5пс steel increases dislocation hardening as a result of a decrease in the increase in the density of dislocations and their preservation during accelerated cooling of hot-worked austenite in rolled products. Keywords: hardening, yield strength, thermomechanical treatment, accelerated cooling, phase components, grain size. aman-kanaev2012@yandex.ru, remshev@mail.ru, mash-kalugin@yande.ru, aliya-981@mail.ru

Improvement in tensile strength of extruded Mg–5Bi alloy through addition of Sn and its underlying strengthening mechanisms

Through an investigation of the microstructure and mechanical properties of extruded Mg–5Bi– x Sn (BT5 x, x = 0, 2, 4, and 6 wt%) alloys, this study demonstrates that the addition of Sn to an Mg–5Bi binary alloy significantly improves the tensile strength of the extruded alloy. All the extruded alloys exhibit a typical basal fiber texture and a partially dynamically recrystallized (DRXed) microstructure consisting of fine DRXed grains and coarse unDRXed grains. As the Sn content increases from 0 wt% to 6 wt%, the average size of the DRXed grains decreases from 4.2 to 2.8 μm owing to the increase in the amount of precipitates via their grain-boundary pinning effect. The extruded B5 and BT52 alloys contain numerous Mg 3 Bi 2 precipitates, but their size and number density are smaller and higher, respectively, in the latter alloy. Numerous Mg 2 Sn precipitates as well as Mg 3 Bi 2 precipitates are present in the extruded BT54 and BT56 alloys, and the number density of the Mg 2 Sn precipitates is higher in the latter alloy because of its higher Sn content. The addition of 2 wt% Sn to the B5 alloy significantly improves the yield strength (YS) and ultimate tensile strength (UTS) of the extruded alloy—by 76 and 57 MPa, respectively. This drastic improvement is the combined outcome of enhanced grain-boundary hardening, precipitation hardening, and solid-solution hardening effects induced by the refined DRXed grains, numerous precipitates, and Sn solute atoms, respectively. The further addition of 2 wt% or 4 wt% Sn to the BT52 alloy leads to moderate increments in the YS and UTS of the extruded alloy. Specifically, each addition of 2 wt% Sn increases the YS and UTS by ~26 and ~20 MPa, respectively, which is attributed mainly to the additional precipitation hardening effect induced by the Mg 2 Sn precipitates.

Hardening mechanisms in stainless steel/aluminum bronze composite fabricated using electron beam additive manufacturing

The authors investigated the features of structural-phase state of a composite based on stainless austenitic steel with addition of 25 % (vol.) aluminum bronze. The composite was obtained by electron beam additive technology with simultaneous feeding of two wires. The paper considers analysis of the structural-phase state and mechanical characteristics. The contributions of various mechanisms to the composite hardening were evaluated. It was established that a multiphase structure is formed in the steel – 25 % bronze composite, which consists of 43.9 % austenite, 32.0 % ferrite and 24.2 % bronze. Dispersion-hardened copper particles are isolated in austenite grains, volume fraction of which counts 47 %. Dispersion-hardened NiAl particles with a volume fraction of 20 % are isolated in ferrite grains. Transmission electron microscopy data indicate a coherent conjugation of arrays of dispersion-hardened particles with the matrix. Such a composite structure provides an increase in the tensile strength by an average of 50 % compared to austenitic steel obtained by electron beam additive technology without the addition of aluminum bronze. It was found that the contributions of various hardening mechanisms to yield strength of austenite, ferrite and bronze amounted to 959.3, 972.7 and 408.7 MPa, respectively. Bronze grains do not make a significant contribution to increase in yield strength of the composite, except for its increase due to dislocation hardening. The main contributions to increase in the composite yield strength are made by austenite grains due to grain-boundary, dispersion and dislocation hardening and by ferrite grains due to grain-boundary, solid-solution and dislocation hardening.

Effective combination of solid solution strengthening and precipitation hardening in NiCrFeWTiAl multi-principal element alloys

Face-centered-cubic (FCC) Multi-principal element alloys (MPEAs) have attracted intensive scientific research interest due to their excellent fracture toughness and ductility. Still, the strengths of single-phase MPEAs are unsatisfactory. Although great progress has been made by utilizing multiple strengthening mechanisms, it remains challenging to take advantage of large-atom solutes and nano-precipitates simultaneously because solutes always partition into the precipitates. In the present work, we successfully achieved an effective combination of solid solution strengthening and precipitation hardening in the NiCrFeWTiAl multi-principal element alloys. Our experimental results showed that W is partitioned into the FCC matrix, while Ti and Al tend to exist in the L12 phase. This controlled elemental partitioning leads to a good combination of solid solution strengthening and precipitation hardening effects and results in good tensile properties at temperatures from 25 ℃ to 760 ℃. The strengthening mechanisms were revealed based on the quantified microstructure analysis. The solid solution hardening of all the solute atoms contributes ∼140 MPa in total, but W mainly contributes to solid solution hardening, and L12 precipitates enhance the yield strength by ∼330 MPa through ordering strengthening.

Solid solution softening and hardening in binary BCC alloys

Solute-dislocation interaction energies are calculated using Density Functional Theory and the 2-D lattice Greens function approach for Al, Ti, Cr, Fe, Zr, Nb, Mo, Ru, Hf, Ta, W, Re solutes in BCC Nb, Ta, Mo, and W. The predictions are then used in an extension of the Rao-Suzuki model to analyze the experimentally observed solid solution strengthening and softening in Nb-X, Fe-X, Ta-X, Mo-X and W-X crystals, X= Mo, W, Ta, Si or Re. DFT predictions for the solute dislocation interaction energies for Fe-Si, taken from the literature are also analyzed. The original Rao-Suzuki model considers kink migration controlled mobility of screw dislocations in body-centered cubic (BCC) structures and is valid for high solute concentrations (>5 at%) as well as above a critical temperature. Here, we extend the Rao-Suzuki model to include kink-pair nucleation statistics in the presence of solutes which is expected to be the rate limiting process at low temperatures (<0.2Tmelt). Such an extension should be valid up to low concentration of solutes as well as fairly low temperatures. The key parameters required for the model are solute – ½[111] screw dislocation interaction energies in pure Nb, Ta, Mo or W. These parameters were derived in this paper using first principles calculations. Using the calculated interaction energies, the model satisfactorily reproduces experimentally observed solution strengthening data in Nb-Mo, Nb-W, Nb-Re crystals at temperatures from 77 to 600K, for solute concentrations in the range 8.5 to 19 at% for Mo, 6 to 15 at.% for W and 5 to 9 at.% for Re. Similar agreement is found for strengthening/softening data for Ta-W, Ta-Re, Ta-Nb, Fe-Si, Mo-Re and W-Re crystals in the temperature range 77 – 600K. We also explore sensitivity of these predictions to the variation in the solute-dislocation energies. In Ta-W, a 10% variation (±0.015 eV) produces a modest change in solution hardening, which is within experimental error. The refined Rao-Suzuki model can be used in designing high strength, multi-component BCC alloys for high temperature applications.

Uncovering heterogeneity of local lattice distortion in TiZrHfNbTa refractory high entropy alloy by SR-XRD and EXAFS

Local lattice distortion is usually hypothesized to be severe in TiZrHfNbTa refractory high entropy alloy (RHEA). However, few works have made to quantitatively evaluate element specified distortion and its effect on mechanical behavior of this alloy. In this work, we herein provide a quantitative assessment of element specified local lattice distortion in both the as-prepared and tested TiZrHfNbTa RHEA using a combination of X-ray diffraction and extended X-ray absorption fine structure spectrum (EXAFS). The results show a more significant local lattice distortion (5.2 ± 0.3%) around Zr-center than that (4.0 ± 0.4%) around Nb-center in the as-prepared TiZrHfNbTa RHEA, and the distortion magnitude become more prominent after tensile test. Splitting features are observed in the Fourier transformed EXAFS spectra due to heterogeneous atom motions during deformation. The underlying mechanisms of this element-specified local distortion and its influence on solid solution hardening and ductility degradation are discussed as well.

Hardening Mechanisms in Stainless Steel/Aluminum Bronze Composite Fabricated Using Electron Beam Additive Manufacturing

The authors investigated the features of structural-phase state of a composite based on stainless austenitic steel with addition of 25% (vol.) aluminum bronze. The composite was obtained by electron beam additive technology with simultaneous feeding of two wires. The paper considers analysis of the structural-phase state and mechanical characteristics. The contributions of various mechanisms to the composite hardening were evaluated. It was established that a multiphase structure is formed in the steel–25% bronze composite, which consists of 43.9% austenite, 32.0% ferrite and 24.2% bronze. Dispersion-hardened copper particles with 47 vol % content precipitated inside the austenite grains while only 20 vol % of the dispersion-hardening NiAl particles precipitated in the ferrite grains. Transmission electron microscopy data indicate a coherent conjugation between crystalline lattices of these dispersion hardening particles and matrix. Such a composite structure provides 50%, on average, improvement of the tensile strength compared to that of austenitic steel obtained by electron beam additive technology without the addition of aluminum bronze. It was found that the contributions of various hardening mechanisms to yield strength of austenite, ferrite and bronze amounted to 959.3, 972.7 and 408.7 MPa, respectively. Bronze grains do not make a significant contribution to increase of the yield strength of the composite, except for its increase due to dislocation hardening. The main contributions to the increase of the composite yield strength are made by austenite grains due to grain-boundary, dispersion and dislocation hardening, and by ferrite grains due to grain-boundary, solid-solution and dislocation hardening.

Entropy engineering enhances the thermoelectric performance and microhardness of (GeTe)1−x(AgSb0.5Bi0.5Te2)x

As an endogenous material genetic property, entropy is an emerging fingerprint factor in the material genome. By designing multicomponent thermoelectric materials with high configuration entropy, the lattice thermal conductivity can be significantly reduced via severe lattice distortion, and the Seebeck coefficient can be improved by enhancing the crystal symmetry. However, high entropy also causes the deterioration of carrier mobility, restraining the improvement of the dimensionless figure of merit zT. Herein, we design the (GeTe)1−x(AgSb0.5Bi0.5Te2)x, aka TABGS alloys, via replacing half of the Sb by Bi in the well-known (GeTe)1−x-(AgSbTe2)x, aka TAGS alloys, to attest the efficacy of entropy engineering. In view of the low carrier mean free path of TAGS alloys approaching to the Mott-Ioffe-Regel limit, further Bi substitution and increased configuration entropy cannot impair the carrier mobility any longer. In addition, the suppressed rhombohedral-cubic phase transition via high configuration entropy and the reduced carrier concentration contribute to the substantially improved Seebeck coefficient. Furthermore, the elicited multiscale microstructures and the decreased sound velocity upon AgSb0.5Bi0.5Te2 alloying effectively restrain the lattice thermal conductivity. As a result, (GeTe)0.80(AgSb0.5Bi0.5Te2)0.20 achieves a high zT of 1.60 at 723 K and an average zTave of 1.23 from 300 to 773 K. Meantime, its room-temperature Vickers hardness reaches 2.21 GPa due to solid solution hardening. These results highlight the efficacy of entropy engineering in enhancing the thermoelectric performance, especially for numerous materials with intrinsically low carrier mobility.

Direct comparison of C and N effect on hydrogen embrittlement of stable 17Cr-10Ni-6Mn austenitic stainless steel

The effects of C and N on hydrogen embrittlement (HE) were investigated in 17Cr-10Ni-6Mn based stable austenitic stainless steels containing 0.2 wt% of either C or N. C and N increased tensile strength by solid solution hardening and high-density dislocation accumulation. C was more effective on further strengthening by active TWIP effect than N. The lattice expansion by C and N decreased hydrogen diffusivity and depth of hydrogen-affected zone, which increased the HE resistance. The HE resistance was further enhanced by C than N due to lower hydrogen diffusivity and crack severity and active cross slip by C.

Influence of delta ferrite on the impact toughness of a PH 13-8 Mo maraging steel

Due to the fact that maraging steels are widely utilized as structural parts for the aerospace industry, high and consistent impact toughness is crucial to ensure reliability under extreme mechanical loads. The toughness of maraging steels is heavily influenced by the martensitic structure and reverted austenite. Another microstructural constituent is residual delta ferrite that originates from non-equilibrium solidification. This work focuses on the effect of delta ferrite on the impact toughness of a PH 13-8 Mo maraging steel, while keeping other toughness-influencing factors as constant as possible. Three-step heat treatments were applied to samples for adjusting different phase fractions of delta ferrite. Charpy impact testing revealed that the impact toughness decreases with an increasing phase fraction of delta ferrite. However, no significant influence on the lower energy shelf, i.e. the impact energies below the ductile-to-brittle transition temperature range, was found. In addition, no decrease in hardness at room temperature was measured when delta ferrite is present in the microstructure. Particle analysis by APT measurements revealed that delta ferrite contains Ni- and Al-rich precipitates. It is assumed that those precipitates in combination with effective solid solution hardening by Cr, Mo and Al significantly contribute to the hardness of delta ferrite, which is in the range of martensite. Furthermore, EDS analysis showed a depletion in Ni in delta ferrite, presumably resulting in a lower cleavage fracture resistance compared to martensite, and, therefore, causing embrittlement. Moreover, the interface between delta ferrite and martensite possibly plays an additional role for crack initiation due to amplified local stresses.

Development of Ti-Mo-Fe alloys combining different plastic deformation mechanisms for improved strength-ductility trade-off and high work hardening rate

Titanium-based biomaterials are the gold standard for orthopedic implants; however, they are not generally suitable for the manufacture of intravascular stents. Their low strength-ductility trade-off and low work hardening rate are their main limitations. However, Ni-free alloys are desirable for such application in order to avoid allergic reactions caused by the high Ni-content materials currently applied. Therefore, in this study, three alloys of the Ti-Mo-Fe system (Ti-8Mo-2Fe, Ti-9Mo-1Fe and Ti-10.5Mo-1Fe) were designed to present high strength-ductility compromise and high work hardening rate. Their microstructures, mechanical properties and plastic deformation mechanism were investigated. Athermal ω precipitates were observed in the β matrix of all solution-treated alloys. In the solution-treated β matrix of the Ti-9Mo-1Fe alloy, additional nanometer-sized α" particles were detected by transmission electron microscopy (TEM). Although the combined TWIP/TRIP effects were expected by the design method on the Ti-8Mo-2Fe and Ti-9Mo-1Fe alloys, no TRIP effect was actually observed. In fact, stress-induced martensitic (SIM) transformation occurred mainly at the {332}<113> twins/matrix interfaces for all the strained microstructures and acted as a localized stress-relaxation mechanism, delaying the fracture. Based on the electron backscatter diffraction (EBSD) analyses, in the Ti-8Mo-2Fe and Ti-10.5Mo-1Fe alloys, the formation of a dense network of {332}<113> twins was responsible for their high and steady work hardening rates (1370 and 1120 MPa) and large uniform elongations (22% and 34%). The absence of SIM α" as the primary mechanism of plastic deformation and solid solution hardening of Fe resulted in their high strengths (yield strength of 772 and 523 MPa). In Ti-9Mo-1Fe, the formation of mechanical twinning was hindered, resulting in limited strain-hardening capability and low uniform elongation (6%). The nanometer-sized α" particles in its β matrix along with the athermal ω precipitates are thought to impair the mechanical twinning and the ductility of this alloy.

The way to improve strength and ductility of heavily carbon-alloyed high-entropy Fe20Mn20Cr20Ni20Co15C5 alloy

In this work we propose a new approach to improve strength and ductility of the heavily carbon-alloyed high entropy Fe20Mn20Cr20Ni20Co15C5 alloy, which is characterized by extremely low plasticity in cast state (δ = 5%, σUTS = 633 MPa). Novel thermal treatment regime, combining 5-h homogenization at T = 1200 °C with intermediate thermal cycling down to the room temperature, provides the 4-times increase in ductility and high values of strength characteristics (δ = 19%, σUTS = 905 MPa) due to the partial dissolution and smoothing of the carbides. Such complex processing regime provides better strength/ductility combination than those for the individual effects of a solid-solution treatment (dissolution of precipitates and solid-solution hardening of the austenite) or a thermal cycling treatment (refinement of carbide inclusions).

Significant hardness improvement of a low-density Al-Si-Mg-Li-Fe alloy through laser-aging surface treatment

High hardness and low density are desirable merits of materials for wearproof structural applications. This paper develops an Al-10Si-2Mg-0.5Li-0.2Fe alloy that is 3.3% lighter than pure Al, and employs laser-aging surface treatment to improve its hardness. After the treatment, second phase particles from tens of micrometers are transformed to an average size smaller than 15 nm. Hardness of the alloy reaches 194 HV, entering the highest level of Al alloys lighter than pure Al. Meanwhile, corrosion resistance of the alloy in 3.5% NaCl aqueous solution is enhanced by about 34%, due to alleviated micro-galvanic corrosion. Equations are established for evaluating contributions from grain refinement hardening, solid solution hardening and precipitation hardening effects. Accordingly, they are calculated to account for 4.4%, 50% and 45.6%, respectively. This inspires high hardness Al alloy design through taking full advantage of oversaturation and nano-scale precipitation.

Crystallographic texture of tape substrates for HTSC from Cu-40%Ni alloy with additives of refractory elements

The texture of deformation and primary recrystallization in copper-nickel alloys with the addition of a small amount of refractory elements such as Nb, Mo, Ta and W was studied. Based on the X-ray analysis of the deformation texture using the orientation distribution function, it was shown that the volume fraction of the C and S components in alloys is greater than the double volume fraction of the unfavorable component B. In accordance with this criterion, after primary recrystallization in all the studied alloys, a sharp cubic texture {100}< 001 > was obtained with a volume fraction in the± 10° region of more than 95%. Alloying with refractory elements significantly increases the strength of the base copper-nickel alloy by the mechanism of solid-solution hardening. The evaluation of the mechanical characteristics showed that the increase in the yield stress in the studied alloys is from 25% to 45% with relative to Cu-40% Ni alloy.

Solid solution hardening effects on structure evolution and mechanical properties of nanostructured binary and high entropy alloys after high pressure torsion

Two different alloy series (Cu-X, Ni-X) have been selected to investigate the effects of solutes on the saturation grain size, the thermal stability and mechanical properties after high pressure torsion. The results of the Cu-X series indicate that the saturation grain size does not correlate with the stacking fault energy but shows good agreement with solid solution hardening according to the Labusch model. This correlation does not only hold for binaries, but also for chemically complex high entropy alloys (Ni-X) in the form of (CrMnFeCo)xNi1-x, where the Varvenne model is used to describe solid solution hardening. The alloy series exhibit a grain size in the range of 50 – 425 nm after high pressure torsion and the solutes increase the strength as well as the thermal stability of the alloys after annealing. The nanostructured alloys exhibit an enhanced strain rate sensitivity exponent, as determined from nanoindentation strain rate jump and constant contact pressure creep testing, whereas an enhanced rate sensitivity is found at low strain rates. The relatively lower rate sensitivity of the alloys as well as their higher thermal stability indicate, that defect storage and annihilation is strongly influenced by a complex interaction of solutes, dislocations and grain boundaries.

MECHANICAL IMPROVEMENT OF HARDENING AND TEMPERING STEEL WITH THE ADDITION OF SiC AND TiCN NANOPARTICLES IN THE STEEL MELT

Novel processing technologies have allowed the reinforcement of several steel grades and alloys through the fine dispersion of different types of particles. However, the addition of ceramic particles in the steel melt causes agglomeration and coarsening phenomena. For this reason, little research has been carried out to add ceramic particles in steel in the traditional steelmaking process. Here we report a hardened and tempered steel grade that is reinforced for the first time through the addition of ceramic nanoparticles, such as TiCN and SiC, into the steel melt at laboratory scale. The results obtained from the tensile tests and hardness measurements reveal the mechanical behaviour of the steel grade is enhanced after the addition of the nanoparticles. KEYWORDS: Hardened and tempered steel; Nanoparticle; Laboratory scale casting; Microstructure; Grain refinement; Solid solution hardening; Mechanical properties

Structure and low-temperature micromechanical properties of as-cast and SPD-processed high-entropy Co25−xCr25Fe25Ni25Cx alloys

The effect of carbon additions on the structure and mechanical properties of high-entropy alloys Co25−xCr25Fe25Ni25Cx (x = 0, 1, 3, at. %) in two structural states, as-cast coarse-grained (CG) samples and nanocrystalline (NC) obtained by severe plastic deformation (SPD), was studied. The SPD was performed by high-pressure torsion at room temperature. The mechanical properties were investigated by microindentation in the temperature range of T = 77−300 K. It was found that in the as-cast state, all alloys had a dendritic microstructure and an inhomogeneous distribution of elements. At x = 0 and x = 1, the dendrites were enriched in iron and nickel, and the interdendrite regions were enriched in chromium. At x = 3, in the interdendrite regions, a eutectic consisting of a multicomponent matrix and fine eutectic dendrites of M7C3 carbide, where M is predominantly chromium, was formed. The main phase in alloys had an fcc lattice, while the solubility of carbon in it was about 1 at. %. SPD led to the effective refinement of the microstructure (the size of the coherent scattering regions was about 30−50 nm), to an increase in the dislocation density up to (1−1.5)⋅1015 m−2 and to an increase in the concentration of stacking faults. The microhardness of CG alloys at room temperature increased monotonically with increasing carbon concentration, while in NC alloys the maximum microhardness HV was achieved at 1 at. % of carbon. The reason for this anomalous behavior of the microhardness of NC alloys is an increase in the grain size and a decrease in the dislocation density in the alloy with x = 3 compared to the alloy with x = 1. As the temperature decreased from room temperature to the temperature of liquid nitrogen, the microhardness of CG and NC alloys increased by about 1.5−1.7 and 1.2−1.5 times, respectively, which indicates the thermally-activated nature of plastic deformation under the indenter. The results obtained indicate that the main role in the hardening of the CG alloys Co25−xCr25Fe25Ni25Cx is due to solid solution and dispersion hardening, while in NC alloys it is hardening due to a decrease in the grain size (according to the Hall-Petch relation) and an increase in the dislocation density (according to the Taylor relation).

Rapid alloy design from superior eutectic high-entropy alloys

The large amounts of data in eutectic high-entropy alloys (EHEAs) provide the opportunity for a rapid design of superior high-entropy alloys (HEAs). In this letter, we proposed a strategy to screen high-performance supersaturated HEAs based on the existing EHEAs with superior properties. The designed HEAs of supersaturated terminal solid solutions possess unique characteristics. On the one hand, the as-cast alloys exhibited primary single-phase dendrites/grains with maximum solid solution hardening and minor interdendritic/intergranular second phases as modifiers. On the other hand, the maximum saturation enabled the highest volume fraction of precipitates during aging. Taking advantage of these characteristics, high strength and ductility were achieved in the designed HEAs. These findings can accelerate the exploration of supersaturated HEAs with superior properties.