Plasma Rotating Electrode Process Research Articles

Microstructure and mechanical properties of Fe–30Mn–9Al–C–3Ni low-density steel manufactured by selective laser melting

Low-density Fe–Mn–Al–C steels are widely used in the automotive and aerospace industries as advanced lightweight materials. In this study, highly spherical Fe–30Mn–9Al–C–3Ni powder with a narrow particle-size distribution, low oxygen content, and good flowability was prepared using the plasma rotating electrode process (PREP). Furthermore, Fe–30Mn–9Al–C–3Ni low-density alloy steel was manufactured for the first time using the selective laser melting (SLM) molding technique. Laser power was found to significantly impact the microstructure and mechanical properties of SLM-printed Fe–30Mn–9Al–C–3Ni alloys. The Fe–30Mn–9Al–C–3Ni alloy prepared at a laser power of 110 W (denoted as P-110) exhibited the best mechanical properties, including a yield strength of 887.1 MPa, tensile strength of 1076.8 MPa, elongation of 40.80%, and a maximum hardness value of 294 HV. This study highlights the potential of SLM molding for fabricating low-density Fe–Mn–Al–C steels with complex geometrical shapes and outstanding comprehensive mechanical properties.

Microstructure and Mechanical Properties of the Powder Metallurgy Nb-16Si-24Ti-2Al-2Cr Alloy.

The Nb-16Si-24Ti-2Al-2Cr alloy was prepared by plasma rotating electrode process (PREP) technology and the hot-pressing (HP) method, and the effects of sintering temperature on the microstructure, mechanical properties and fracture behavior were investigated. The HP alloys sintered at temperatures below 1400 °C are composed of Nbss (Nb solid solution), Nb3Si and Nb5Si3 phases. When the sintering temperature reaches 1450 °C, the Nb3Si phase is completely decomposed into Nbss and Nb5Si3 phases. Meanwhile, the microstructure coarsens significantly. Compared with the cast alloy, the HP alloy shows better mechanical properties. The fracture toughness of the alloy sintered at 1400 °C reaches 20.2 MPa·m1/2, which exceeds the application threshold. The main reason for the highest fracture toughness is attributed to the decomposition of large-sized brittle Nb3Si phase and the formation of a fine microstructure, which greatly increases the number of phase interfaces and improves the chance of crack deflection. In addition, the reduction in the size and content of silicides also reduces their plastic constraints on the ductile Nbss phase.

Prospective life cycle assessment of titanium powder atomization

The environmental sustainability of titanium powders production mainly depends by atomization that is the most diffused technology in this field, ensuring the environmental advantages of high mass flow rate, energetical efficiency and reduced waste which have greatly encouraged its diffusion on an industrial scale. However, few quantitative assessment studies have been proposed on atomization sustainability and none of them consider the many technological evolutions of atomization that the industries are working on. This study proposes a prospective life cycle assessment (LCA), of the ex-ante type, of future new Electrode Induction Gas Atomization (EIGA) and Plasma Rotating Electrode Process (PREP) that will produce Ti6Al4V powders in 2035. This time point, referring to a medium-term view is considered to ensure the relevance and the reliability of technology forecasts based on quantitative estimates. Both the systems have been modelled through data retrieved from patents to assess their future impacts. The prospective LCA shows that in the future EIGA the average impact, in each indicator, will be 50% lower for electrical consumption and 98% lower for argon consumption compared to future PREP. The future EIGA and future PREP are more sustainable than the mature EIGA (of the crucible and crucible-free type) and mature PREP (of the traditional and supreme-speed plasma type) currently on the market. The average impact reductions, respectively passing from future to mature EIGA and PREP, are 65% and 23% for electricity consumption and 11% and 28% for argon consumption. The variabilities in technological solutions, scalability and future scenarios about electricity and argon production scale all the impacts without reverse the ranking. At a structural level, the most sustainable solutions are the optimization of the geometries of the titanium bar in the future EIGA and the optimization of the disposition of the plasma gun in the future PREP. This study shows which technological advancement increase the sustainability of EIGA and PREP atomization process in the future and to what extent in the two cases.

Microstructure and mechanical properties of Co31.5Cr7Fe30Ni31.5 high-entropy alloy powder produced by plasma rotating electrode process and its applications in additive manufacturing

Microstructure and mechanical properties of feedstock powders critically determine the quality of additive manufacturing (AM). The present study employs a plasma rotating electrode process (PREP) to produce non-equiatomic Co31.5Cr7Fe30Ni31.5 high-entropy alloy (HEA) powders and examines variations of their microstructure and mechanical properties with powder particle size in the range of 20–106 μm. It finds that the powders possess smooth surfaces, good sphericity, and equiaxed polycrystal grains under PREP electrode rod arc speed of 32000 r/min and main arc current of 760 A. A stable FCC structure is maintained regardless of the powder particle size. Moreover, the nano-hardness of the powders generally decreases with the increase of powder particle size except for that of 50–75 μm, which is positively correlated with the change of the grain size. The finest grain size is present for powders with particle sizes of 50–75 μm, which possess the highest average nano-hardness and reduced elastic modulus. Bulk alloys fabricated by cold spray (CS) and laser cladding (LC) AM maintain the FCC structure. The CSAM bulk alloy shows early brittle fracture due to the presence of pores and prior particle boundaries resulting from insufficient plastic deformation of the powder particles. The LCAM bulk alloy presents good tensile properties with the ultimate tensile strength (UTS) and elongation to failure being 481.2 MPa and 35.9%, respectively, which can be attributed to the good cohesion and grain characteristics. The present study shall provide the field of AM with useful information in the applications of non-equiatomic PREP HEA powders.

Effect of Preparation Process on the Microstructure and Characteristics of TiAl Pre-Alloyed Powder Fabricated by Plasma Rotating Electrode Process

TiAl pre-alloyed powder is the foundation for additive manufacturing of TiAl alloys. In this work, TiAl pre-alloyed powder was prepared using a plasma rotating electrode process (PREP). The effects of electrode rotating speeds and current intensity on the microstructure and characteristics of TiAl pre-alloyed powder have been investigated in detail. The results show that the electrode rotating speeds mainly affected the average particle size of the powder (D50). As the electrode rotating speed increased, the D50 of the powder decreased. The current intensity mainly affected the particle size distribution of the powder. As the current intensity increased, the particle size distribution of the powder became narrower, which was concentrated at 45~105 μm. In addition, the current intensity had a significant effect on the sphericity degree of the powder with the particle size > 105 μm, but it had little effect on that <105 μm powder. TiAl pre-alloyed powder with a particle size > 45 μm demonstrated a dendritic + cellular structure, and the <45 μm powder had a microcrystalline structure. The powder was mainly composed of the α2 phase and γ phase. There were two kinds of phase structure inside the powder, namely the α2 + γ lamellar microstructure (particle size < 45 µm) and the α2 + γ network microstructure (particle size > 45 µm). The phase structure of the powder was related to the solidification path and cooling rate of molten droplets in the PREP. The average thickness of the α2 + γ lamellar was about 200 nm, in which the lamellar γ phases were arranged in an orderly manner in the α2 phase matrix with a thickness of about 20 nm. The network phase structure was corrugated, and the morphology of the γ phase was not obvious.

Powder Synthesis and Characterization of Al0.5CoCrFeNi High-Entropy Alloy for Additive Manufacturing Prepared by the Plasma Rotating Electrode Process.

The Al0.5CoCrFeNi high-entropy alloy powder was produced by using a plasma rotating electrode process. The morphology, microstructure, and physical properties of the powder were characterized. The powder exhibited a smooth surface and a narrow particle size distribution with a single peak. The relationships between particle size and secondary dendrite arm space as well as cooling rate were evaluated as follows: λ = 0.0105d + 0.062 and vc = 4.34 × 10-5d-2 + 2.62 × 10-2d-3/2, respectively. The Al0.5CoCrFeNi powder mainly consisted of fcc + bcc phases. As the powder particle size decreased, the microstructure of the powder changed from dendritic to columnar or equiaxed, along with a decrease in the fcc content and an increase in the bcc content. The tap density (4.76 g cm-3), flowability (15.01 s × 50 g-1), oxygen content (<300 ppm), and sphericity (>94%) of the powder indicated suitability for additive manufacturing.

High-Quality Spherical Silver Alloy Powder for Laser Powder Bed Fusion Using Plasma Rotating Electrode Process.

The plasma rotating electrode process (PREP) is an ideal method for the preparation of metal powders such as nickel-based, titanium-based, and iron-based alloys due to its low material loss and good degree of sphericity. However, the preparation of silver alloy powder by PREP remains challenging. The low hardness of the mould casting silver alloy leads to the bending of the electrode rod when subjected to high-speed rotation during PREP. The mould casting silver electrode rod can only be used in low-speed rotation, which has a negative effect on particle refinement. This study employed continuous casting (CC) to improve the surface hardness of S800 Ag (30.30% higher than mould casting), which enables a high rotation speed of up to 37,000 revolutions per minute, and silver alloy powder with an average sphericity of 0.98 (5.56% higher than gas atomisation) and a sphericity ratio of 97.67% (36.28% higher than gas atomisation) has been successfully prepared. The dense S800 Ag was successfully fabricated by laser powder bed fusion (LPBF), which proved the feasibility of preparing high-quality powder by the "CC + PREP" method. The samples fabricated by LPBF have a Vickers hardness of up to 271.20 HV (3.66 times that of mould casting), leading to a notable enhancement in the strength of S800 Ag. In comparison to GA, the S800 Ag powder prepared by "CC + PREP" exhibits greater sphericity, a higher sphericity ratio and less satellite powder, which lays the foundation for dense LPBF S800 Ag fabrication.

Effects of carbon addition on the microstructure and mechanical property of in-situ reinforced TiAl matrix composite powders produced by plasma rotating electrode process

To investigate effects of carbon addition on microstructural characteristics of rapidly solidified TiAl alloys, Ti–43Al–6Nb-xC (x = 0,0.5,1.0 at.%) powders are produced by plasma rotating electrode process (PREP). Due to the greater viscosity of composite melts with carbides than those without carbides, the average sizes of carbon containing TiAl powders are much larger than theoretical average diameters. In addition, phase compositions of carbon-free TiAl powders usually consist of α phase and β phase, while α phase is predominant in carbon containing TiAl powders due to α-phase stabilizer. β→α phase transformation during the rapid solidification and Burgers relationships {110}β||(0001)α and <111>β||(11–20)α are illustrated in TiAl powders. Three types of microscopic structures are unfolded in TiAl composite powders: smooth structures, dendrite structures and equiaxed structures, which stem from various cooling rates. With carbon contents rising to 1.0 at.%, the average grain size in TiAl powders with the particle size range of 100∼150 μm is refined from 24.31 ± 0.38 μm to 11.32 ± 0.36 μm, moreover, the distribution ranges of particle sizes vary dramatically. Additionally, the micro-hardness of TiAl powders gradually upgrades as carbon contents ascend. The maximum micro-hardness of TiAl composite powders with 1.0 at.% carbon addition touches at 758.7 ± 15.4HV. Solid solution strengthening, refinement strengthening and second-phase strengthening are main sources for the ascent of micro-hardness.

Evolution Behavior of Rapidly Solidified Microstructure of a Ti-48Al-3Nb-1.5Ta Alloy Powder during Hot Isostatic Pressing

In this study, Ti-48Al-3Nb-1.5Ta powders were manufactured from cast bars by the supreme-speed plasma rotating electrode process (SS-PREP) and used to prepare hot isostatically pressed (HIPed) material at 1050–1260 °C with 150 MPa for 4 h. The phase, microstructure and mechanical performance were analyzed by XRD, SEM, electrical universal material testing machine and other methods. The results revealed that the phase constitution changed from γ phase to α2 phase and then to γ phase with the material changing from as-cast to powders and then to as-HIPed. Compared with the as-cast material, the grain size and element segregation were significantly reduced for both powders and as-HIPed. When the hot isostatic pressing (HIP) temperature was low, the genetic characteristics of the powder microstructure were evident. With the HIP temperature increasing, the homogeneity of the composition and microstructure increased, and the prior particle boundaries (PPBs) gradually disappeared. The elastic moduli of powder and as-HIPed were superior to those of as-cast, which increased with the HIP temperature increasing. The hardness of as-HIPed was lower than that of the powder. The compressive strength, compressive strain, bending strength, and tensile strength of as-HIPed were higher than those of as-cast. With an increase in the HIP temperature, the compressive strength decreased gradually, and the compressive strain first decreased and then increased.

Achieving high hardness and wear resistance in phase transition reinforced DC53 die steel by laser additive manufacturing

Additive manufacturing (AM) becomes a potential way to prepare molds, since it provides an effective option to produce parts with complex geometries in fewer steps. Among the mold steel materials, DC53 is considered as a superior steel grade by die and mold making industries due to its high hardness and wear resistance. However, the fabrication of spherical DC53 powder and its AM processing feasibility has not yet been reported. In the present work, spherical DC53 powder and its AMed parts were prepared by plasma rotating electrode process (PREP) and laser-directed energy deposition (LDED), respectively. The feasibility of DC53 powder for LDED preparation and the mechanical properties of laser directed energy deposited (LDEDed) parts were investigated. It is found that the spherical DC53 powder prepared by PREP is well suited for LDED. The kinetic effects during PREP change the phase composition of DC53 powder (transformation from pearlite to austenite). Compared to commercially available DC53 (cast DC53 after heat treatment), the LDEDed part exhibits comparable relative density. Normally, the main phase in commercially available DC53 is pearlite. Since the LDED process is still a rapid prototyping process, the main phase in LDED parts is the same as that in the powder, which is γ-Fe. Interestingly, the phase transformation induced by kinetic effects could increase the hardness and wear resistance of DC53 effectively (the hardness has increased by 28.2 % and the wear rate has reduced by 47 %.), which is of great significance for the fast and efficient preparation of high performance molds.

Solidification Behavior and Microstructures Characteristics of Ti-48Al-3Nb-1.5Ta Powder Produced by Supreme-Speed Plasma Rotating Electrode Process

Solidification Behavior and Microstructures Characteristics of Ti-48Al-3Nb-1.5Ta Powder Produced by Supreme-Speed Plasma Rotating Electrode Process

First principles study of Ti-Zr-Ta alloy phase stability and elastic properties

The effects of Ta and Zr content on the stability, elastic properties and electronic structure of Ti-Zr-Ta alloy phase were studied by first principles calculation method based on density functional theory. Moreover, Ti-Zr-Ta alloy was fabricated by spark plasma sintering (SPS) using spherical Ti powder,Ta powder, and Ti-Zr-Ta alloy powder produced by the plasma rotation electrode process (PREP). Afterward, the effects of sintering temperature, Zr and Ta content on the microstructure and mechanical properties of the alloy samples were investigated. The results showed that sintering temperature, Ta and Zr content were the key factors which affected the densification. When the sintering temperature was raised, the relative density and mechanical properties of Ti-Zr-Ta alloy were significantly increased. The first- principles calculation also indicated that Ti-1Zr-Ta possesses the lowest Young’s modulus and the best ductility, showing great potential of biomedical applications which agrees with the results of experimental results of alloy preparation.

Effect of Powder Characteristics on Relative Density and Porosity Formation During Electron Beam Selective Melting of Al2024 Aluminum Alloy

Abstract Defects, such as pores and cracks, can be found in parts fabricated by powder-bed additive manufacturing techniques. The origin of certain defects, such as some voids, can be linked to initial powder quality, which makes it an important factor in the process. Powders used in additive manufacturing processes are produced by different methods such as gas atomization (GA), plasma atomization (PA), and plasma rotating electrode process (PREP); each gives different powder quality. In this study, two different Al2024 powders, produced by electrode induction GA and PREP techniques, were used to investigate the effect of powder characteristics on defect formation during electron beam melting process (EBM). Powders were first characterized by using Hall flowmeter funnel and scanning electron microscope (SEM); then, the EBM process was carried out, and finally, samples were examined by density measurement using Archimedes method, SEM analysis, and tensile test. PREP powder showed higher levels of sphericity and surface smoothness without attached satellites. Consequently, a higher apparent density and decreased flowing time were achieved in PREP powder. Moreover, gas-induced internal pores were observed in GA particles. The results also revealed the average relative density of 96.7% and 99.4% for the parts built by GA and PREP powders, respectively. SEM micrographs confirmed the results of density measurement of the fabricated parts and showed higher degrees of both spherical and irregular-shaped pores in samples built by GA powder. Additionally, they showed deprived mechanical properties due to the higher porosity contents which can form stress-concentrated areas.

Preparation and Microstructure of High-Activity Spherical TaNbTiZr Refractory High-Entropy Alloy Powders.

High-activity spherical TaNbTiZr refractory high-entropy alloy (REHA) powders were successfully prepared by electrode induction melting gas atomization (EIGA) and plasma rotating electrode process (PREP) methods. Both the EIGAed and PREPed TaNbTiZr RHEA powders have a single-phase body-centered cubic (BCC) structure and low oxygen content. Compared with the EIGAed powders, the PREPed powders exhibit higher sphericity and smoother surface, but larger particle size. The average particle sizes of the EIGAed and PREPed powders are 51.8 and 65.9 μm, respectively. In addition, both the coarse EIGAed and PREPed powders have dendritic structure, and the dendrite size of the EIGAed powders is larger than that of the PREPed powders. Theoretical calculation indicates that the cooling rate of the PREPed powders is one order of magnitude higher than that of the EIGAed powders during the solidification process, and the dendritic structure has more time to grow during EIGA, which is the main reason for the coarser dendrite size of the EIGAed powders.

Development of macro-defect-free PBF-EB-processed Ti–6Al–4V alloys with superior plasticity using PREP-synthesized powder and machine learning-assisted process optimization

The elimination of internal macro-defects is a key issue in Ti–6Al–4V alloys fabricated via powder bed fusion using electron beams (PBF-EB), wherein internal macro-defects mainly originate from the virgin powder and inappropriate printing parameters. This study compares different types powders by combining support vector machine techniques to determine the most suitable powder for PBF-EB and to predict the processing window for the printing parameters without internal macro-defects. The results show that powders fabricated via plasma rotating electrode process have the best sphericity, flowability, and minimal porosity and are most suitable for printing. Surface roughness criterion was also applied to determine the quality of the even surfaces, and support vector machine was used to construct processing maps capable of predicting a wide range of four-dimensional printing parameters to obtain macro-defect-free samples, offering the possibility of subsequent development of Ti–6Al–4V alloys with excellent properties. The macro-defect-free samples exhibited good elongation, with the best overall mechanical properties being the ultimate tensile strength and elongation of 934.7 MPa and 24.3%, respectively. The elongation of the three macro-defect-free samples was much higher than that previously reported for additively manufactured Ti–6Al–4V alloys. The high elongation of the samples in this work is mainly attributed to the elimination of internal macro-defects.

Effect of radio-frequency plasma spheroidization on the microstructure and mechanical properties of 10Cr ferritic oxide dispersion-strengthened steel

Reducing the porosity of irregularly shaped mechanically alloyed oxide dispersion-strengthened (ODS) steel powders is critical for their application at cryogenic temperatures. Although the plasma rotating electrode process has been widely used as a suitable method for producing spherical powders, its high cost and low powder yield impede its application. Thus, we investigated the feasibility of applying plasma spheroidization on ODS steel particles, to reduce their porosity, by investigating the influence of radio-frequency plasma spheroidization on the microstructure and mechanical properties of 10-Cr ODS steel. The ODS steel powder was ball-milled and then spheroidized prior to consolidation. The prepared samples were analyzed using X-ray diffraction, electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM) as well as subjected to tensile and impact tests. The EBSD analysis revealed that the grains in the plasma-spheroidized sample were coarser than those in the non-spheroidized sample, and thus, the room- and cryogenic-temperature Charpy impact strengths of the latter were superior to those of the former sample. TEM analysis showed that the average particle size of plasma-spheroidized ODS steel was slightly higher than that of the non-plasma-spheroidized ODS steel. Furthermore, the room-temperature yield strength of the non-spheroidized ODS was higher than that of the spheroidized ODS because of the finer grains of the former. In the future, plasma spheroidization can be combined with other techniques to obtain completely dense ODS steel with increased upper shelf energies for various advanced and military applications.

Modification of magneto-caloric effect in spherical La-Fe-Co-Si compounds particles by hydrogen permeation

The spherical La-Fe-Co-Si compound particles with giant magneto-caloric properties prepared by plasma rotating electrode process (PREP) and hydrogen permeation were obtained and their mechanism was investigated in this paper. Compared with the alloys prepared by the traditional melting and casting methods, the spherical particles prepared by the PREP have a uniform and refined structure and benefit to form the NaZn 13 -type phase with giant magneto-caloric effect (MCE). The magnetic properties of spherical particles with three different sizes show that the particles with size between 450 µm and 600 µm had the best magneto-caloric properties, the isothermal magnetic entropy change can reach 12.67 J·kg −1 ·K −1 , corresponding to the applied magnetic field changes of 0 −1.5 T. Hydrogen permeation can increase the Curie temperature ( T c ) of spherical particles, which can be ascribed to the magneto-volume effect caused by change in cell volume. When the hydrogen permeation pressure is 100 Pa, the T c increases from 218 K to 224 K, and the structure of the spherical particles remains stable at this time. The spherical La-Fe-Co-Si compound particles with giant MCE and excellent heat exchange ability are promising materials for commercial applications of magnetic refrigeration technology. • The spherical LaFe 11.3 Co 0.2 Si 1.5 alloy prepared by the plasma rotating electrode process has a uniform and fine structure. • The spherical particles can completely form NaZn 13 -type phase after heat treatment at 1373K for 120h. • Adjusting the appropriate hydrogen permeation pressure can keep the structure stable and increase the Curie temperature.

Influence of Powder Characteristics on the Microstructure and Mechanical Behaviour of GH4099 Superalloy Fabricated by Electron Beam Melting

A Chinese superalloy, GH4099 (~20 vol.% γ′ phase), which can operate for long periods of time at temperatures of 1173–1273 K, was fabricated by electron beam melting (EBM). Argon gas atomized (GA) and plasma rotation electrode process (PREP) powders with similar composition and size distribution were used as raw materials for comparison. The microstructure and mechanical properties of both the as-EBMed and post-treated alloy samples were investigated. The results show that the different powder characteristics result in different build temperatures for GA and PREP samples, which are 1253 K and 1373 K, respectively. By increasing the building temperature, the EBM processing window shifts towards a higher scanning speed direction. Microstructure analysis reveals that both as-EBM samples show a similar grain width (measured to be ~200 μm), while the size of γ′ precipitated in the PREP sample (~90 nm) is larger than that of the GA sample (~130 nm) due to the higher build temperature. Fine spherical γ′ phase precipitates uniformly after heat treatment (HT). Furthermore, intergranular cracking was observed for the as-fabricated PREP sample as a result of local enrichment of Si at grain boundaries. The cracks were completely eliminated by hot isostatic pressing (HIP) and did not re-open during subsequent heat treatment (HT) of solution treatment and aging. The tensile strength of the PREP sample after HIP and HT is ~920 MPa in the building direction and ~850 MPa in the horizontal direction, comparable with that of the wrought alloy.

A comparative study on laser powder bed fusion of IN718 powders produced by gas atomization and plasma rotating electrode process

The effects of powder feedstocks prepared by different methods on the processibility of the powders and the performance of final components have largely been unexplored in metal additive manufacturing (MAM). In this paper, we conducted a comparative study on the laser powder bed fusion (LPBF) process of Inconel 718 (IN718) powders produced by gas atomization (GA) and plasma rotating electrode process (PREP), respectively. For the GA and PREP powders, the powder characteristics, such as chemical composition, particle size distribution (PSD), powder morphology and powder defects are initially characterized and compared. Parallel single-track experiments and cuboid components printing have also been designed and carried out in the LPBF process by using these two types of powders. Forming quality and mechanical properties of different components are systematically evaluated. The results show that the powder feedstocks do not significantly affect the mechanical properties under the optimized LPBF process parameters. However, the PREP powder, with smooth surface, higher sphericity, higher apparent density and better flowability, can obtain a larger processing window and more stable mechanical properties of the as-built parts than the GA powder.

Non-equilibrium solidification behavior associated with powder characteristics during electron beam additive manufacturing

For components built by powder bed fusion with electron beam (PBF-EB), the resulting microstructure arising from non-equilibrium solidification, microsegregation and the formation of interdendritic phases significantly affects the material properties. Notably, the powder characteristics influence the heat absorption and conduction, thereby altering the molten pool behavior and solidification parameters. However, the effect of the powder feedstock on solidification during PBF has not been widely investigated. In this study, a CoCrMo alloy was fabricated using powders prepared by gas-atomization (GA) and plasma rotating electrode process (PREP). Under the given operating conditions, samples built using the two powders were characterized and compared. By performing multi-scale numerical simulations, melting and solidification were visualized and analyzed to elucidate the mechanism through which the powder characteristics influence the non-equilibrium solidification behavior during PBF-EB. The study revealed that after appropriate size control, compared with the GA powder, the PREP powder had a smaller specific surface area and higher sphericity; thus, the generated powder layer exhibited higher heat absorption and dissipation rates. Therefore, a high solidification rate was facilitated, thereby suppressing microsegregation. These findings contribute to PBF knowledge related to feedstock, proving to be an essential reference for selecting and optimizing metallic powders applicable to additive manufacturing.