Powder Metallurgy and Metal Ceramics最新文献

{"title":"Effect of Structural Refinement on the Mechanical Properties of Fe–28 Al Intermetallic Alloy Produced by Direct Powder Forging IV. Analysis of the Structural Sensitivity of Low-Temperature Strengthening, Heat Resistance, and Creep Resistance","authors":"O. I. Tolochyn,&nbsp;O. V. Tolochyna,&nbsp;G. A. Bagliuk,&nbsp;M. I. Danylenko,&nbsp;I. Yu. Okun,&nbsp;Ya. I. Yevych,&nbsp;Yu. M. Podrezov","doi":"10.1007/s11106-026-00545-0","DOIUrl":"10.1007/s11106-026-00545-0","url":null,"abstract":"<p>The influence of structural refinement in iron aluminide on low-temperature strengthening, heat resistance, and creep resistance in the temperature range 650–750°C was studied. The phase and structural states in which the studied materials demonstrated the best combination of properties were determined. At room temperature, the greatest contribution to low-temperature strengthening was provided by grain size reduction. Compression test results showed that the highest strengthening was exhibited by the samples forged from ground powders. The alloy reinforced with 0.3 at.% CrB₂ demonstrated the highest yield stress at room temperature (1176 MPa) resulting from the formation of the finest structure. Dynamic recrystallization under optimal thermokinetic conditions promoted ultrafine grains (1–2 μm) and fine boride particles (~100 nm). The temperature dependences of yield stress showed abnormal values for all samples. Over the entire test temperature range, the greatest strengthening was exhibited by the samples produced by triple deformation. Significant softening was observed above 600°C. The alloys reinforced with boride particles softened most slowly. At 700°C, the yield stress remained at the level of ~450 MPa. With an increase in temperature to 750°C, the alloy containing 1.5 at.% CrB₂ had higher yield stress than the alloy with 0.3 at.% CrB₂ (207 MPa and 120 MPa, respectively). Over the temperature range 650–750°C, structural refinement favorably influenced creep resistance. At 700°C, under a load of 120 MPa, the best creep resistance was demonstrated by the two-component Fe–28 Al alloy produced by forging from ground powders under dynamic recrystallization conditions and by the alloy reinforced with 1.5 at.% CrB₂. In both cases, the creep rate was <i>ε′</i> ~ 3.3 · 10^–7 sec^–1. A comparative analysis of the creep resistance of Fe–28 Al matrix composites with 0.3 and 1.5 at.% CrB₂ at 700 and 750°C under loads of 90 and 120 MPa showed that, under all selected deformation conditions, the alloy with the higher boride content exhibited better creep resistance, since fine incoherent particles provided the main contribution to high-temperature strengthening.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 9-10","pages":"525 - 534"},"PeriodicalIF":0.8,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148695481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure and Properties of γ-TiAl Alloys Doped with Niobium, Molybdenum, Chromium, and Boron","authors":"A.A. Bondar,&nbsp;O.O. Bilous,&nbsp;Yu.M. Podrezov,&nbsp;S.O. Firstov,&nbsp;N.I. Tsyganenko,&nbsp;V.M. Voblikov,&nbsp;O.M. Myslyvchenko,&nbsp;V.I. Danylenko","doi":"10.1007/s11106-026-00544-1","DOIUrl":"10.1007/s11106-026-00544-1","url":null,"abstract":"<p>Alloys based on γ-TiAl with 44 and 47 at.% Al, doped with 4 at.% Nb, 1 at.% Mo, 0.5 at.% Cr, and 0.1 at.% B, were melted in an arc furnace from pure materials. Their structure, phase transformation temperature, and deformation mechanism were studied using the results of tensile tests at elevated temperatures. Optimal Al/Ti ratios were determined and effective heat treatment parameters were established to ensure high mechanical properties. Scanning electron microscopy found that grains in the as-cast and annealed alloys with 44 at.% Al consisted of α₂ + γ lamellar colonies. The grain boundaries contained the β₀ phase and γ globules, which disappeared during annealing to transform into γ lamellae. The as-cast and annealed alloy samples with 47 at.% Al consisted of α₂ + γ lamellar colonies and the β₀ phase at the grain boundaries. X-ray diffraction revealed that the alloys with 47 at.% Al had 30–40% more γ phase than those with 44 at.% Al. The cubic β₀ phase content differed little. The alloys with higher aluminum content were shown to be more ductile at all test temperatures. They exhibited higher elastic modulus and fracture toughness but significantly lower yield stress. The fracture stress was comparable, weakly depended on temperature, and ranged from 1100 to 1300 MPa. For both groups of alloys, strength parameters remained quite high throughout the test temperature range (20–750°C). At room temperature, the hardening rate of the alloys with 44 at.% Al was three times that of the alloys with 47 at.% Al. In the brittle–ductile transition region, these alloys showed increased sensitivity of ultimate strain to strain rate. For the Ti_47.5Al₄₇Nb₄Cr_0.5Mo₁ alloy tested at 650°C, a decrease in the strain rate by only one order of magnitude led to an almost threefold increase in ductility. The distinctive behavior of the studied intermetallics is attributed to the pronounced strain-rate sensitivity of relaxation processes, determining the mechanism of dislocation motion over the temperature range of brittle–ductile transition.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 7-8","pages":"510 - 523"},"PeriodicalIF":0.6,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147865731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure and Mechanical Properties of Aluminum Nitride Composites with Diamond Powder and Carbon Black Additives","authors":"T. B. Serbeniuk,&nbsp;T. O. Prikhna,&nbsp;V. B. Sverdun,&nbsp;V. E. Moshchil,&nbsp;M. V. Karpets,&nbsp;H. D. Ilnytska,&nbsp;A. A. Marchenko,&nbsp;L. O. Polikarpova,&nbsp;V. V. Bilorusets,&nbsp;S. P. Starik","doi":"10.1007/s11106-026-00537-0","DOIUrl":"10.1007/s11106-026-00537-0","url":null,"abstract":"<p>The structurization and mechanical properties of AlN-based composite ceramics were studied. Composite samples were prepared from powder mixtures containing 3% diamond powder of various grain sizes and 5% carbon black by hot pressing at 1900–1920°C under a pressure of 12–13 MPa. X-ray diffraction revealed the main phases in the composites, such as AlN, Al₃(O, N)₄ and graphitic carbon, while scanning electron microscopy was employed to determine their grain sizes and distribution within the structure. Analysis of all composites showed a uniform distribution of graphite inclusions with an average size of 0.2–5 μm over the entire sample surface, with smaller inclusions corresponding to finer diamond powder in the starting mixture. Hardness measurements with a Vickers indenter were performed at a load of 49 N, and fracture toughness was calculated from the measured lengths of radial cracks emanating from the indentation corners. At comparable densities (3.23–3.24 g/cm³), the highest hardness (<i>HV</i> = 11.79 ± 0.38 GPa) and fracture toughness (<i>K</i>_1c = 7.01 ± 0.04 MPa∙m^0.5) were shown by materials with an average graphite grain size of approximately 1 μm, corresponding to the composites prepared with 1/0 μm diamond grains in the starting powder mixture. It was established that an increase in the grain size of the starting diamond powder and, accordingly, an increase in the grain size of the graphite phase in the composite resulted in decreased mechanical properties. Additionally, since the material containing 5% carbon black had lower density (3.19 g/cm³) compared to other composites, it exhibited the lowest mechanical properties: <i>HV</i> = 7.6 ± 0.31 GPa and <i>K</i>_1c = 4.28 ± 0.34 MPa∙m^0.5.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 7-8","pages":"446 - 454"},"PeriodicalIF":0.6,"publicationDate":"2026-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147865572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Structural Refinement on the Mechanical Properties of Fe–28 Al Intermetallic Alloy Produced by Direct Powder Forging III. Development of High-temperature Consolidation Route for Fe–28 Al Iron Aluminide for Dynamic Recrystallization Conditions","authors":"O.I. Tolochyn,&nbsp;O.V. Tolochyna,&nbsp;G.A. Bagliuk,&nbsp;S.F. Kyryliuk,&nbsp;M.I. Danylenko,&nbsp;I.Yu. Okun,&nbsp;Yu.M. Podrezov","doi":"10.1007/s11106-026-00533-4","DOIUrl":"10.1007/s11106-026-00533-4","url":null,"abstract":"<p>A high-temperature consolidation route based on direct powder forging under dynamic recrystallization conditions was developed. An original die design was proposed to enable plastic deformation in a closed die cavity through controlled displacement of a flash layer. Using the DEFORM 2D/3D software package, the optimal conditions for the dynamic recrystallization mechanism were identified as three deformation steps at a temperature of 1150–1200°C. After each forging step, the cross-sectional density, strain intensity, and distribution of radial strains were calculated. Under the optimal process conditions for dynamic recrystallization, iron aluminide samples produced from powders with different initial morphologies were forged. For unground iron and aluminum powders, recrystallization resulted in clean grain boundaries, locally decorated with fine particles. Fracture proceeded via a transcrystalline mechanism. The bending strength reached 1220 MPa. For ground iron and aluminum powders subjected to deformation processing, anisotropic grains with an average transverse size of ~2 μm were observed. No continuous segregation layers were present at the grain boundaries, and a large number of fine particles (&lt;0.3 μm) were found. In this structural state, the bending strength increased to σ_b = 1835 MPa. For composites with a presynthesized Fe₃Al matrix reinforced with boride particles, triple forging at 1150°C produced a superfine structure. The grain size was estimated at 2–3 μm, and the average boride particle size was 50–100 nm. In the samples doped with 0.6 vol.% chromium boride, the room-temperature strength reached 2029 MPa with nearly 3% ductility and a fracture toughness of 48.6 MPa · m^1/2, which was higher than in all the above cases.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 7-8","pages":"397 - 415"},"PeriodicalIF":0.6,"publicationDate":"2026-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147865732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of Sucrose in the Charge for Reaction Sintering of SiC-Based Ceramics","authors":"O. V. Neshpor,&nbsp;Fang Ningxiang,&nbsp;Wang Yucong,&nbsp;Chen Piaopiao,&nbsp;Ye. Yu. Chighankov","doi":"10.1007/s11106-026-00535-2","DOIUrl":"10.1007/s11106-026-00535-2","url":null,"abstract":"<p>Sucrose (sugar) is proposed as a replacement for conventional phenol formaldehyde resins in charges for the production of reaction-sintered silicon carbide. The main disadvantage of phenol formaldehyde resins is their high toxicity. In addition, the storage life of such resins is limited and requires refrigerated conditions. The shelf life of charges prepared with phenol formaldehyde resins is only several days. The shelf life of charges containing sucrose extends up to two months (at an ambient temperature of 25–30°C). Thus, the use of sugar syrup as a plasticizer significantly improves the environmental conditions of production, reduces harmful releases into the environment, extends the shelf life of the charges, and lowers production costs. The starting charge (dry) contained approximately 19 wt.% primary carbon (carbon black) and 81 wt.% silicon carbide. A plasticizer (60% sugar syrup) was introduced in the charge in an amount of 15 wt.%, which added approximately 2 wt.% secondary carbon to the final composition of the compacts. As a result, the compacts contained 79 wt.% silicon carbide and 21 wt.% carbon. The optimal compaction pressure was 8 MPa. The coke (secondary carbon) that formed after pyrolysis of sucrose exhibited 25% greater porosity than the coke produced by pyrolysis of phenol formaldehyde resins. This facilitated the transport of silicon vapors inside the compacts during reaction sintering, allowing the production of sintered articles with a specific density of 3.08–3.10 g/cm³. The hardness of the plates produced in this way increased from 23 to 25 GPa. X-ray examination and chemical analysis of the samples were performed, and their microstructure and mechanical properties were studied. These results were used to establish the optimal mean particle size for the starting silicon carbide powder and the required sucrose addition for producing dense ceramic composites with high mechanical properties.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 7-8","pages":"424 - 429"},"PeriodicalIF":0.6,"publicationDate":"2026-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147865733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase Equilibria in the Hf2Ni7–Ni–TiNi3 Region of the Hf–Ni–Ti System","authors":"V.F. Kravchuk,&nbsp;A.M. Storchak,&nbsp;N.S. Novichenko,&nbsp;M.V. Bulanova","doi":"10.1007/s11106-026-00541-4","DOIUrl":"10.1007/s11106-026-00541-4","url":null,"abstract":"<p>Phase equilibria in the nickel-rich corner of the Hf–Ni–Ti system were studied using physicochemical analysis methods, including differential thermal analysis, scanning electron microscopy, electron probe microanalysis, and X-ray diffraction. The liquidus and solidus projections, isothermal sections at 1000 and 700°C, and a vertical section along the 87.5 at.% Ni isopleth were constructed. This revealed the features of phase transformations over a wide temperature range in the Hf₂Ni₇–Ni–TiNi₃ region. The results confirmed the presence of invariant four-phase L ⇄ (Ni) + HfNi₅ + TiNi₃ and L ⇄ HfNi₅ + TiNi₃ + Hf₂Ni₇ eutectic transformations in this region at 1215 and 1200°C, respectively. Differences between our liquidus projection and previously published versions based on thermodynamic modeling were discussed. Alternative nature of the equilibria was established at 1000 and 700°C as compared to the solidus projection. The nature of the equilibria was found to change between 1200 and 1000°C through the solid-state (Ni) + Hf₂Ni₇ ⇄ HfNi₅ + TiNi₃ transformation. The microstructure of samples from all primary crystallization regions was analyzed. The samples from the TiNi₃ primary crystallization region crystallized in a nonequilibrium way, contributing to the glass formation in eutectic melts. The research is novel in that it fills gaps in experimental data for the high-nickel composition range. This is an important step toward further predicting the glass-forming ability of multicomponent alloys and optimizing their chemical composition for practical applications.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 7-8","pages":"483 - 496"},"PeriodicalIF":0.6,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147865655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Silicon on the Corrosion of Ti–xSi Alloys in Seawater","authors":"V.M. Talash,&nbsp;M.M. Kuz’menko,&nbsp;Yu.B. Rudenko,&nbsp;V.A. Shvets,&nbsp;O.M. Shevchenko","doi":"10.1007/s11106-026-00542-3","DOIUrl":"10.1007/s11106-026-00542-3","url":null,"abstract":"<p>The effect of silicon content on the structure and corrosion resistance of Ti–xSi alloys in a 3 wt.% NaCl solution simulating seawater was examined. Arc melting in an argon atmosphere was employed to produce Ti–1.2Si, Ti–3.6Si, Ti–5.7Si, and Ti–2Si–3Al alloys. Silicon was partly retained in solid solution in the Ti–xSi alloys and, when its solubility limit was exceeded, formed an excess Ti₅Si₃ silicide phase. At silicon contents above 1.5–2.1 wt.% Si, the amount of the Ti₅Si₃ phase as a eutectic component increased substantially. Electrochemical studies were conducted by plotting potentiodynamic curves for anodic dissolution of the initial surfaces and cathodic reduction curves in forward and reverse scans and then anodic curves for the reduced surfaces. The Ti–xSi alloys showed adequate corrosion resistance. With increasing contents of silicon and the strengthening silicide phase, and with the associated transition from polycrystalline to eutectic structure, the anodic stability of the alloys improved. The addition of 3 wt.% aluminum to the Ti–2Si alloy enhanced corrosion resistance over the range from the open-circuit potential to the onset of anodic dissolution, after which the corrosion resistance of the Ti–2Si–3Al alloy became comparable to that of the other Ti–xSi alloys. Preliminary cathodic treatment of the Ti–xSi alloys demonstrated significant hysteresis between the forward and reverse cathodic curves, resulting from the removal of surface impurities by atomic cathodic hydrogen and involving substantial improvement in the anodic stability of the alloys. The relative content of the Ti₅Si₃ silicide phase on the Ti–xSi alloys and the oxide nanofilms formed in exposure to aggressive environments were found to have the decisive role in the increase of their corrosion resistance.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 7-8","pages":"497 - 503"},"PeriodicalIF":0.6,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147865652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effect of Distortion on the Mechanical Properties of High-Entropy Solid-Solution Alloys Determined by Instrumented Indentation","authors":"V.F. Horban","doi":"10.1007/s11106-026-00543-2","DOIUrl":"10.1007/s11106-026-00543-2","url":null,"abstract":"<p>A new class of materials, high-entropy alloys, has attracted attention of many researchers because of high mechanical properties. The distinctive features of these materials include: increased entropy, contributing to thermal stability; distortion, as one of the strengthening mechanisms; mixing enthalpy, influencing the interaction between atoms; and cluster structure within the grains, complicating the movement of dislocations and promoting increased strength. Experimental data from instrumented indentation for a large group of high-entropy alloys based on bcc, fcc, and bcc + fcc phases were analyzed, and relationships between the hardness, effective elastic modulus, normalized hardness, elastic strain, elastic limit, distortion, and ratio of hardness to ultimate strength were established. In the studied alloys, the hardness ranged from 2.0 to 8.3 GPa, the elastic modulus from 81 to 233 GPa, and the distortion from 0.82 to 5.89%. The absence of a proportional dependence of hardness and elastic modulus on distortion in solid-solution high-entropy alloys was demonstrated. A proportional dependence of the normalized hardness, ranging from 0.052 to 0.018, and elastic strain on the distortion level for bcc, fcc, and bcc + fcc high-entropy alloys was determined. The elastic limit and yield stress, determined by different methods for bcc, fcc, and bcc + fcc high-entropy alloys, are in good agreement with each other.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 7-8","pages":"504 - 509"},"PeriodicalIF":0.6,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147865627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research Progress on Corrosion Protection of Cemented Carbides","authors":"Yumeng Ni,&nbsp;Zichao Hu,&nbsp;Dong Wang,&nbsp;Jiangxiong Gao,&nbsp;Caihe Fan","doi":"10.1007/s11106-026-00536-1","DOIUrl":"10.1007/s11106-026-00536-1","url":null,"abstract":"<p>Hard alloys are indispensable in modern manufacturing fields such as aerospace, metallurgy, and electronic communication due to their high hardness, excellent wear resistance, and red hardness. However, the cobalt binder in WC–Co alloys is prone to corrosion, leading to selective dissolution, depletion of the binder, and loosening of the hard phase, thereby limiting service life. This article reviews the latest progress in the corrosion protection of hard alloys. Firstly, the article traces the development of hard alloys and emphasizes key innovations: protective coatings, gradient structures, and nanocrystalline treatment. Secondly, the article summarizes the main types of corrosion, including galvanic corrosion, fatigue corrosion, high-temperature corrosion, and friction corrosion. It explains how each type of corrosion damages the microstructure (e.g., grain coarsening, binder loss) and the mechanical properties (e.g., hardness, strength). Thirdly, the article outlines three core mitigation strategies: (i) adding chromium or nickel as the binder; (ii) using surface coatings such as CrN or TiB₂; (iii) optimizing cleaning and treatment to reduce corrosion triggers. This review provides a concise and practical basis for designing hard alloys with high strength and long-lasting corrosion resistance.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 7-8","pages":"430 - 445"},"PeriodicalIF":0.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147865573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of Composite Powders to Produce Heavy Tungsten-Based Alloys by Radiation and Electron Beam Sintering","authors":"K. V. Polishchuk,&nbsp;A. V. Minitskyi","doi":"10.1007/s11106-026-00534-3","DOIUrl":"10.1007/s11106-026-00534-3","url":null,"abstract":"<p>The coating of tungsten powder agglomerates with nickel by chemical deposition from salt solutions was examined. The influence of nickel chloride solution concentration and deposition kinetics on the nickel content and coating thickness were studied. At a NiCl₂ concentration of 30 g/l, approximately 8% nickel was deposited on the tungsten powder agglomerates, while an increase in the NiCl₂ concentration to 60 g/l raised the deposited nickel content to 80%. Kinetic studies of the deposition process over 60–120 min showed that the nickel content reached 20–22% after 60 min. When the deposition time was extended to 90 min, the nickel content increased to 75–80%. The effect of tungsten powder agglomerate sizes on the nickel chemical deposition process was examined, and differences in the coating caused by varying specific surface areas of the agglomerates were established. Finer agglomerates with sizes of 20–25 μm, with larger specific surface areas, exhibited increased contact between the neighboring particles and reduced contact with the solution, which limited complete nickel coverage. Larger agglomerates, with significantly smaller specific surface areas, showed a nickel layer 5–7 μm thick. The influence of nickel coating on the morphology of tungsten particles was studied; the powder physical and process characteristics changed (flowability decreased from 2.33 sec/50 g to 2.64 sec/50 g and bulk density from 7.77 g/cm³ to 6.51 g/cm³). The effect of isothermal holding time during sintering of compacts produced from nickel-coated tungsten powders was established. During radiation sintering with prolonged holding times, recrystallization of tungsten particles occurred through the liquid phase, leading to tungsten grain growth by a factor of 2.5–3. During electron beam sintering with short holding times, no recrystallization of tungsten particles occurred, resulting in a fine structure with a grain size of approximately 20 μm without the formation of intermetallic compounds.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 7-8","pages":"416 - 423"},"PeriodicalIF":0.6,"publicationDate":"2026-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147865653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}