Homogeneous Microstructure Research Articles

Study on bonding properties and constitutive model of steel bar and nano-SiO2 reinforced recycled aggregate concrete

Optimizing design and ensuring the structural safety of recycled aggregate concrete (RAC) structures requires a thorough understanding of the bond-slip mechanism between steel bars and RAC. Previous studies have demonstrated the significant enhancement of the microscopic properties of RAC and its bond with steel bars due to nano-SiO2. However, the structural bonding mechanism between the steel bar and nano-SiO2-enhanced RAC remains unclear. Therefore, this study investigates the influence of nano-SiO2 on the bond performance between RAC and steel bars, elucidating the enhancement mechanism through microscopic techniques. Additionally, various factors affecting the bond-slip performance of RAC specimens are analyzed, leading to establishing a multifactorial coupling formula considering thickness-to-diameter ratio, concrete strength, and relative anchorage length. Furthermore, slip index correction formulas and a constitutive model are developed, considering these factors. Acoustic emission (AE) technology monitors the bonding process, clarifying the evolution of AE digital signals and bond damage history. Employing the finite element method, a numerical model of bond-slip behavior is established, revealing specimens' changing bond strength and failure modes. Experimental results indicate that increasing nano-SiO2 content reduces structural porosity, leading to denser and more homogeneous microstructures, thereby enhancing RAC's mechanical properties and bonding performance. Moreover, AE techniques effectively monitor bond damage at different stages. Finally, a bond-slip constitutive model is proposed for steel bar and nano-SiO2 reinforced RAC, offering insights for numerical calculations and engineering designs.

Elucidating the effects of metal transfer modes and investigating the material properties in wire-arc additive manufacturing (WAAM)

AbstractStudies have shown the influence of WAAM process parameters on mechanical properties, bead formation, dimensional accuracy, and microstructure. However, metal transfer modes and their interactions with input variables have not been investigated thoroughly. Therefore, short/spray, pulse and double pulse modes were investigated in this study at different current levels. Bead-on-plate trials were conducted by depositing ER70S-6 wire to investigate bead morphology, dilution, microstructure, and hardness. The study was supported by a detailed statistical approach, including analysis of variance (ANOVA) and regression analysis. Similarly, the combined effects of hatch distance and current were studied on bead formation in multi-layer deposits. Moreover, a thin wall and a cubic structure were deposited to realize the WAAM capability for larger depositions. The microstructures of thin wall and cubic structure were analyzed using optical microscopy (OM) and scanning electron microscopy (SEM). The study concludes that metal transfer modes at various currents significantly influence bead geometry, microstructure and hardness. The microstructure of bead-on-plate trials show fine lamellar structure at low current in all modes. Higher current results in coarse grains with a polygonal and columnar morphology. The hardness shows a decreasing trend as the current increases. The combined effects of current and hatch distance alter bead morphology; however, an optimized combination yields smoother surfaces. The microstructure of thin wall showed a slight anisotropy along the building direction. The presence of small pores was witnessed from OM and SEM images. Similarly, the cubic structure showed a more homogeneous microstructure with much lower porosity. The hardness profile of the thin wall exhibited small fluctuations along the building direction, while that of the cubic structure was more uniform.

Sulfur/carbon cathode material chemistry and morphology optimisation for lithium-sulfur batteries.

Lithium-sulfur batteries (LSBs) are a promising alternative to lithium-ion batteries because sulfur is highly abundant and exhibits a high theoretical capacity (1675 mA h g-1). However, polysulfide shuttle and other challenges have made it difficult for LSBs to be commercialised. Here, a sulfur/carbon (S/C) composite was synthesised and cathodes were fabricated via scalable melt diffusion and slurry casting methods. Carbon nanoparticles (C65) were used as both sulfur host and electrical additive. Various carbon ratios between the melt-diffusion step and cathode slurry formulation step were investigated. An increased amount of C65 in melt-diffusion led to increased structural heterogeneity in the cathodes, more prominent cracks, and a lower mechanical strength. The best performance was exhibited by a cathode where 10.5 wt% C65 (TC10.5) was melt-diffused and 24.5 wt% C65 was externally added to the slurry. An initial discharge capacity of ∼1500 mA h g-1 at 0.05C and 800 mA h g-1 at 0.1C was obtained with a capacity retention of ∼50% after 100 cycles. The improved electrochemical performance is rationalised as an increased number of C-S bonds in the composite material, optimum surface area, pore size and pore volume, and more homogeneous cathode microstructure in the TC10.5 cathode.

Homogenization Heat Treatment and Tribological Properties of In Situ Alloyed NiTiCu by Laser Powder‐Bed Fusion

In situ alloying by additive manufacturing (AM) of premixed powders has been recognized as a promising low‐cost method for creating complex parts for biomedical implants, in which homogenization heat treatment is a critical concern in this technology. Also, as promising implant materials, their tribological properties under dry and lubrication conditions are significantly concerned with evaluating the functionalities of 3D printing. This work preliminarily addresses these two concerns with the laser powder‐bed fusion (LPBF) 3D‐printed nickel titanium copper (NiTiCu) alloy using three homogenization heat treatments and ball‐on‐disc wear tests under dry and NaCl‐lubricated conditions. It is found that to achieve sufficiently good microstructural homogeneity with low porosity, a temperature of 800 °C and a duration of 5 h is needed. Despite the promising outcome, analysis of the results revealed that all heat treatments led to the formation of a secondary phase identified as Ti2(Ni,Cu), which induced two‐step phase transformations. Thus, further studies on the optimization of the postprocessing techniques are required. The heat‐treated alloy resulting in the most favorable properties is selected for tribological testing. AM and the addition of Cu are observed to enhance the wear resistance of the alloy under lubrication conditions.

Microstructural characterization of interfaces between cold sprayed copper and electrodeposited copper corrosion barrier coatings for used nuclear fuel containers

Copper coatings on steel, manufactured by a novel combination of two different manufacturing technologies, electrodeposition and cold spraying, are employed as a corrosion barrier in the current design of used fuel containers (UFCs) for the long-term storage of Canada's used nuclear fuel. This study examines such copper coatings on a prototype container section, with a particular focus on the interface region where copper materials fabricated by the two processes converge. Distinct microstructures for the electrodeposited and cold sprayed copper layers were observed. An unexpected recrystallized layer on top of electrodeposited copper was identified for the first time. Local annealing at 350 °C and 600 °C for one hour resulted in more homogeneous microstructures and Vickers hardness profiles among the copper layers, which is favorable for this application by reducing processing related heterogeneity in the interface region. More homogenized structures with high fractions of special grain boundaries in this region are expected to provide enhanced mechanical and corrosion properties.

A new severe plastic deformation technique of combined extrusion and torsion to prepare bulk ultrafine grained copper

Reducing grain size is a well-established method for strengthening metals. In this study, a novel severe plastic deformation technique—combined extrusion and torsion (CET) with composite strain—was developed to fabricate bulk ultrafine grained metals. A single pass of CET treatment (with a rotation velocity of 1 r/s and extrusion speed of 3 mm/s) refined coarse-grained copper from 54 μm to 450 nm at room temperature, resulting a significant increase in hardness from 0.55 GPa to 1.3 GPa. The CET technique addresses the limitations of conventional extrusion-processed copper (without torsion), which suffers from gradient microstructure and hardness distribution. It provides enhanced strain accumulation under the same extrusion ratio conditions. The more homogeneous microstructures and properties of CET-processed copper rods are attributed to the reduced strain gradient due to torsion. Additionally, targeted finite element analysis indicated that the CET technology requires 37 % less extrusion load and offers at least 30 % more strain compared to conventional extrusion methods. Compared with other severe plastic deformation methods, such as equal channel angular pressing and high-pressure torsion, which involve simpler deformation processes, the CET technique shows considerable promise for large-scale manufacturing of ultrafine-grained metals.

Study on dynamic recrystallization and precipitation behavior of hot compressed Al-20Zn-0.5Mg-0.5Sc alloy

The dynamic recrystallization (DRX) behavior of the Al-20Zn-0.5Mg-0.5Sc alloy was investigated under specific conditions using a Gleeble-3500 thermal simulator. The resultant grain size, recrystallization degree and precipitated phases were studied. The results indicate that the sensitivity of DRX grain size is highly affected by temperature, feebly influenced by strain and intermediately affected by strain rate. The DRX grains are grown by an average of 3.49 μm with increasing temperature. The DRX behavior is sensitive to temperature, strain and strain rate, resulting in changes in average grain size, percentage of HAGBs and degree of recrystallization under different parameters. At 400 ℃ / 40 % / 0.1 s−1, the average grain size is refined to 12.90 μm, and the corresponding HAGBs and recrystallization degree are approximately 46.2 % and 34.3 %, respectively. The Al3Sc, Zn and η (MgZn2) phases are precipitated in the hot-compressed alloy. The Al3Sc phase promotes the precipitation of the Zn and η phases. The size, amount and morphology of Al3Sc, Zn and η phases at different parameters have an important influence on the movement of dislocations and nucleation of grains, which leads to changes in DRX grain size and the degree of recrystallization. The fine precipitated phase particles Al3Sc and η inhibit the growth of recrystallized grain by pinning grain boundaries and exerting a blocking force on dislocations. Dynamic precipitation is the dominant mechanism for the changes in DRX grain size and degree of recrystallization. To achieve the refined grains and homogeneous microstructures, the optimum parameters are recommended as 400 ℃, 0.1 s−1 and 50 %.

Unraveling the effects of strain‒induced precipitation on continuous cooling ferrite transformation in titanium‒molybdenum microalloyed steel

Strain‒induced precipitation is a characteristic physical‒metallurgical phenomenon during hot‒rolling in microalloyed steel production that strongly affects the overallthermomechanical control process. In this study, the strain‒induced precipitation behavior in titanium‒molybdenum microalloyed steel was comprehensively investigated, and its complex effects on the austenite/ferrite transformation during continuous cooling were analyzed for the first time, based on stress relaxation and multi‒aspect characterization methods. The stress relaxation results revealed that the fastest strain‒induced precipitation occurred at 900 °C. The precipitates were identified as FCC structured (Ti, Mo)C particles with a coherent or semi‒coherent cubic‒cubic orientation relationship to the austenite matrix. The strain‒induced precipitation proved to increase the ferrite transformation temperature and proportion, significantly refine and homogenize the transformed grains. The intermittent quenching at 0.5 C/s further revealed that the (Ti, Mo)C particles with cubic‒cubic orientation relationship to austenite matrix exerted a dual pinning effect: by pinning dislocations, these particles facilitated diffusion‒controlled ferrite nucleation and growth both at austenite grain boundaries and within grains; by pinning migrating phase interfaces, the particles inhibited the coarsening of ferrite grains. Coupled with compressive testing and strengthening contribution analysis, the strain‒induced precipitation was shown to weaken precipitation strengthening but enhance grain refinement strengthening, thereby providing a novel approach to achieving an optimal balance between microstructural homogeneity and mechanical properties.

Processing and characterization of Ultra High Temperature High‐Entropy (Ti0.2Zr0.2Hf0.2Mo0.2W0.2)B2-based Ceramics: Effect of W granulometry, graphite, and SiC addition

A highly dense and single phase (Ti0.2Zr0.2Hf0.2Mo0.2W0.2)B2 ceramic product is obtained in this work at 1950°C (20 min, 20 MPa) by Spark Plasma Sintering (SPS) from powders prepared by Self-propagating High-temperature Synthesis (SHS). The formation of the (W,Mo)B2 secondary phase is avoided using fine W precursors and adding 1 wt% graphite to the SHS powders before SPS. Kinetic limitations responsible for hindering the synthesis of the high entropy boride are correspondingly eliminated. The resulting 98.5 % dense sample exhibits a homogeneous microstructure, with Vickers hardness of 26.8 GPa. The introduction of 20 vol% SiC produces an increase of the KIC values from 2.32 to 5.11 MPa m1/2. Very relevant is that the volatilization of Mo- and W-oxides occurring during sample oxidation at high temperature, which leads to its rapid degradation with the formation of a very porous oxide scale, can be strongly inhibited by the silicate phases generated in the composite ceramic.

Development of Flexible and Partly Water-Soluble Binder Systems for Metal Fused Filament Fabrication (MF3) of Ti-6Al-4V Parts.

Metal Fused Filament Fabrication provides a simple and cost-efficient way to produce dense metal parts with a homogenous microstructure. However, current limitations include the use of hazardous and expensive organic solvents during debinding for flexible filaments the stiffness of filaments made from partly water-soluble binder systems. In this study, the influence of various additives on different partly water-soluble binder systems, with regard to the flexibility and properties of the final parts, was investigated. Furthermore, a method using dynamic mechanical analysis to quantify the flexibility of filaments was introduced and successfully applied. For the first time, it was possible to produce flexible, partly water-soluble filaments with 60 vol.% solid content, which allowed the 3D printing of complex small and large parts with a high level of detail. After sintering, density values of up to 98.9% of theoretical density were achieved, which is significantly higher than those obtained with existing binder systems.

Novel Fe-rich hypo-eutectic high entropy alloy developed for laser powder bed fusion in the Al-Co-Cr-Fe-Ni-Zr system

A novel heat resistant Fe-rich hypo-eutectic high entropy alloy (HEA) was manufactured using laser powder bed fusion (LPBF). The prealloyed Al1/4Co2Cr2Fe6Ni3/2Zr powder was characterized and processed using different preheating temperatures (650°C, 700°C and 800°C). The as-built microstructure showed dissimilar morphologies throughout the melt pool, with eutectic grains of ultra fine lamella spacing (λ≈25 nm) inside the core regions, and coarser dendritic and globulitic growth patterns at the interlayer boundaries (ILBs). An annealing treatment at 1000°C for 6 h yielded a homogenous composite microstructure of a Fe-rich matrix with ∼40 % of fine dispersed Zr-rich intermetallic (IM) phases of submicron size. Synchrotron high energy x-ray diffraction (HEXRD) revealed M2Zr Laves (M = Co, Fe, Ni) as the main IM for the as-built condition and the additional growth of M23Zr6 upon annealing. Further HEXRD in-situ high temperature tests examined the lattice parameter evolution and coefficient of thermal expansion (CTE) up to 1100°C. The mechanical performance of the as-built and annealed condition was evaluated through hardness and compression testing at room temperature (RT). Additional compression testing from RT to 1000°C were conducted on the annealed condition to assess the high temperature strength and give comparison to other high temperature materials like Ni-based superalloys.

Toward the Production of Hydroxyapatite/Poly(Ether-Ether-Ketone) (PEEK) Biocomposites: Exploring the Physicochemical, Mechanical, Cytotoxic and Antimicrobial Properties.

The development of hydroxyapatite (HAp) and polyether ether ketone (PEEK) biocomposites has been extensively studied for bone repair applications due to the synergistic properties of the involved materials. In this study, we aimed to develop HAp/PEEK biocomposites using high-energy ball milling, with HAp concentrations (20%, 40%, and 60% w/v) in PEEK, to evaluate their physicochemical, mechanical, cytotoxicity, and antimicrobial properties for potential applications in Tissue Engineering (TE). The biocomposites were characterized by structure, morphology, apparent porosity, diametral compression strength, cytotoxicity, and antimicrobial activity. The study results demonstrated that the HAp/PEEK biocomposites were successfully synthesized. The C2 biocomposite, containing 40% HAp, stood out due to the optimal distribution of HAp particles in the PEEK matrix, resulting in higher compression strength (246 MPa) and a homogeneous microstructure. It exhibited antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, with no cytotoxicity observed. These properties make the C2 biocomposite promising for regenerative medicine applications, combining mechanical strength, bioactivity, and biocompatibility.

Prediction of Failure Due to Fatigue of Wire Arc Additive Manufacturing-Manufactured Product

Currently, the focus of production is shifting towards the use of innovative manufacturing techniques and away from traditional methods. Additive manufacturing technologies hold great promise for creating industrial products. The industry aims to enhance the reliability of individual components and structural elements, as well as the ability to accurately anticipate component failure, particularly due to fatigue. This paper explores the possibility of predicting component failure in parts produced using the WAAM (wire arc additive manufacturing) method by employing fractal dimension analysis. Additionally, the impact of manufacturing imperfections and various heat treatment processes on the fatigue resistance of 30CrMnSi steel has been investigated. Fatigue testing of samples and actual components fabricated via the WAAM process was conducted in this study. The destruction of the examined specimens and products was predicted by evaluating the fractal dimensions of micrographs acquired at different stages of fatigue testing. It has been established that technological defects are more dangerous in terms of fatigue failure than microstructural ones. The correctly selected mode of heat treatment for metal after electric arc welding allows for a more homogeneous microstructure with a near-complete absence of microstructural defects. A comparison of the fractal dimension method with other damage assessment methods shows that it has high accuracy in predicting part failure and is less labor-intensive than other methods.

Influence of friction stir processing (FSP) on arc directed energy deposited 316L stainless steel: a corrosion science study

Friction stir processing (FSP) was employed as a post-printing surface modification technique to enhance surface properties of arc-directed energy deposited 316L austenitic stainless-steel parts. Corrosion properties and passivity of stir zone and base metal were investigated in 3.5 wt.% NaCl solution. Results reveal a gradual improvement in corrosion protection ability of formed passive film on the alloy's surface over time. Specifically, FSPed region exhibited superior passive behavior and uniform corrosion resistance compared to base metal. This improvement was attributed to a more homogeneous microstructure of stir zone, which hindered micro-galvanic coupling effect. However, it was observed that FSP-treatment did not effectively impede the propagation of pitting corrosion.

Revealing the evolution of microstructure and mechanical properties with deposition energy and shielding gas to achieve phase-balanced directed energy deposition of 2205 duplex stainless steel

Directed energy deposition-arc (DED-arc) manufactured duplex stainless steel (DSS) has shown great potential for use in marine propellers. However, challenges remain in achieving phase-balanced DSS deposits through the DED-arc process. To overcome this, we conducted a study that involved regulating the deposition energy and shielding gas with the use of ER2205 wire. The results show that the austenite content in DSS deposits increases with the increase of deposition energy, and the content in the Ar+2%N2-protected deposits is significantly higher than that of Ar+2%CO2-protected deposits. Ultimately, DSS deposits with balanced phase content (austenite content of ∼48.4 %) are obtained at a line energy of 600 J/mm for DED-arc under Ar+2%N2 protection. Unlike the N loss in Ar+2%CO2-protected samples, more nitrogen elements are introduced into the DSS samples by Ar+2%N2 shielding gas. Ar+2%N2-protected samples contain more austenite and exhibit a more homogeneous microstructure, which results in the solid solution strengthening and a significant reduction in the anisotropy of the tensile properties. Furthermore, a more systematic evolution of the microstructure and tensile properties of DSS deposits under the influence of deposition energy and shielding gas is revealed. This study preliminarily obtains the relationship between the DED-arc parameters, microstructure, and tensile properties of DED-arc-fabricated DSS, which will provide an important reference for tailoring microstructure and properties in additive-manufactured DSS.

Effect of electric arc surfacing on the structure and properties of coatings

Surfacing, like welding, is associated with heating metals in a wide range of temperatures and subsequent cooling of heated zones at different rates. This leads to complex structural and phase changes that are crucial for operational properties of the “protected material – coating” joint. The structure and properties of the alloyage zone of these two materials depend on the degree of penetration, nature of the intermediate layers that arise, and carbon diffusion in the boundary areas. When surfacing on low-carbon steel, depending on the composition of the deposited metal, the structures with a predominant amount of martensite or austenite can be obtained in the alloyage zone, depending on carbon content. The structure and mechanical properties of the bimetallic joint between carbon steel and stainless steel were studied depending on the modes of electric arc surfacing (submerged arc surfacing in one pass, in argon for one and two passes). It was established that the structural and phase composition of the deposited metal is austenite, finely dispersed carbides and a needle component. The structure of the layer deposited in argon in one pass is more homogeneous and does not contain defects. The microhardness increases smoothly along the depth of the deposited layer. As a result of surfacing in argon in two passes, the joint has a homogeneous microstructure, but a large number of microdefects are formed in the layer, which can further lead to the formation of a crack near the alloyage boundary. In submerged surfacing, the heating rate and specific heat input are insufficient, therefore, the surfacing bath is poorly mixed, which leads to a suboptimal structure and the formation of thermal stresses at the alloyage boundary and to the formation of a coating that is heterogeneous in structure and microhardness.

Microstructural evolution and mechanical properties of maraging steel by additive manufacturing

Laser powder bed fusion (LPBF) is a revolutionary and innovative technology that provides advanced technical support for the forming of parts with high precision and complex structures. In this work, a new type of Fe-Ni-Mo-Ti-Al-Y cobalt-free maraging steel was successfully fabricated by LPBF. The additive manufacturing parameters and the microstructural evolution of cobalt-free maraging steel under different heat treatment parameters were systematically studied. The results show that the parts without cracks and close to complete density can be fabricated under a wide LPBF process window. The dislocation cell with 500 nm in the printing state makes the material have good plasticity. After post-heat treatment, the preferred orientation of LPBF maraging steel is reduced, but the typical characteristics of molten pool and cellular structure in maraging steel disappeared, which is the result of local composition and microstructure homogenization. The elongation of LPBF maraging steel in solution annealed state is higher than that in as-printed state, which is due to the reduction of dislocation density and grain coarsening. However, after direct aging, due to the formation of nano-sized Ni3(Ti, Mo) precipitates in the matrix, the mechanical properties of the material were effectively enhanced, and the tensile strength increases from ∼1.1 GPa in as-printed state to ∼1.6 GPa in aging state. In contrast, the corrosion resistance of as-printed maraging steel is higher and comparable to that of traditional cobalt-containing maraging steel. However, the corrosion resistance of LPBF maraging steel after being aged is reduced, which is due to the existence of precipitates and dislocations. This study provides a theoretical reference for the composition design and strengthening mechanism of LPBF cobalt-free maraging steel.

Thermal properties and microstructure of Al–Sn alloys

The Al–Sn alloys feature excellent wear and corrosion resistance, along with good mechanical properties. They are mostly used as bearing materials. However, the application of these alloys as phase change materials (PCMs) for thermal energy storage (TES) has recently been suggested. To assess the adequacy of these alloys in a given area, a detailed evaluation of their thermal properties is required. In the present study, Al–Sn alloys with 11.7, 22.4, 32.8, 41.1, and 53.4 at.% Sn were produced by melting of pure metals. The melt was continuously stirred to avoid segregation, after which casting was carried out in a stainless steel mold. The obtained ingots had a homogeneous microstructure without the appearance of cracks and pores. The thermal diffusivities of the solid Al–Sn alloys in the temperature interval 25–150 °C were measured using the light flash method. The densities at room temperature were measured by the Archimedes method, and the specific heat capacities at different temperatures were calculated using the calculation of phase diagrams (CALPHAD) method. Then the thermal conductivities for studied Al–Sn alloys were obtained by the specific conversion equation. The phase transition temperatures and related heat effects were studied using differential scanning calorimetry (DSC). Variations of thermal conductivity with composition and temperature were determined as well as variation of latent heat of fusion with alloy composition. Moreover, the microstructures and phase compositions of the alloys were examined using scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS). The present research results provide important information on the thermal properties and microstructure of the Al–Sn alloys for designing new PCM for thermal energy storage.

Correlation between zeta potential and electron paramagnetic resonance of thulium, europium co-doped yttria based suspensions

The formation of advanced ceramic components with homogeneous microstructure and functional characteristics demands a suitable control of particle dispersion. Thus, the characterization of particle stability as immersed in a liquid medium is important. The present paper reports an approach to evaluate the stability of europium, thulium co-doped yttria (YET) nanoparticles by a correlation between zeta potential and Electron Paramagnetic Resonance (EPR) techniques. Based on results, YET suspensions exhibited high stability apart from pH 10, while their isoelectric point presented a slight variation from pHIEP 8.5 to 9.2 according to thulium content 0 and 2 at.%, respectively. The peak-to-peak amplitude of EPR spectra of the YET suspensions increased as pH shifted toward alkaline condition, following zeta potential curves features. The present achievements are very useful parameters to form stable suspensions based on rare-earth oxides and to advance toward new materials for radiation dosimetry.

Role of combinative In and Sm additions in tailoring the discharge performance of extruded AZ31 alloys as anodes for seawater batteries

The discharge behaviors of AZ31 alloys, modified by the addition of In and Sm elements in conjunction with equal channel angular pressing (ECAP) processing, were systematically explored. The incorporation of In suppressed the formation of cathodic second phases. In contrast, Sm promoted the precipitation process and therefore led to higher microstructure uniformity following ECAP processing. The solid-solution In contributed to the activated dissolution of Mg matrix and the inhibited hydrogen evolution during discharge, while Sm was beneficial for the uniform dissolution and the alleviation of chunk effect. The results indicated that the 12-pass ECAP processed AZ31-In-Sm anode revealed the most enhanced discharge performance with a discharge voltage of 0.889 V and a utilization of 66.94% at 100 mA cm−2. This improvement can be primarily attributed to the combined effects of the decreased precipitations of cathodic phases by In addition and the enhanced microstructure homogeneity by Sm addition, collaborated with significant microstructure refinement.