{"title":"Construction of CaSnO3:Bi2+ NIR Long-Persistent Luminescent Material with Trap Level Up-Conversion and Bi2+ Concentration Effect","authors":"Weiyan Lei, Fengyan Niu, Qishng He, Yue Wang, Jingui Li, Haotian Wu, Chenxi Guo, Jiashuang Li, Yi Shen","doi":"10.1007/s11106-025-00454-8","DOIUrl":"10.1007/s11106-025-00454-8","url":null,"abstract":"<p>This study focuses on synthesizing and characterizing CaSnO<sub>3</sub>:Bi<sup>2+</sup> near-infrared (NIR) long persistent luminescent materials. NIR persistent luminescent materials enable safe and efficient imaging due to their deep tissue penetration and reduced phototoxicity compared to ultraviolet (UV) excited materials. The CaSnO<sub>3</sub>:Bi<sup>2+</sup> materials were synthesized using a high-temperature solid-state method. The effects of varying Bi<sup>2+</sup> doping concentrations (1, 2, 5, 7, and 10%) on the material’s properties were systematically investigated. The synthesis process was confirmed by X-ray diffraction (XRD) analysis, revealing a perovskite structure for all samples. Scanning electron microscopy (SEM) analysis indicated uniform particle sizes of approximately 1 μm, successfully incorporating Bi<sup>2+</sup> ions confirmed by energy-dispersive X-ray spectroscopy (EDS). The luminescent properties of the CaSnO<sub>3</sub>:Bi<sup>2+</sup> materials were characterized using fluorescence spectroscopy and thermoluminescence spectroscopy. The excitation and emission spectra showed peaks at 260, 620, and 680 nm, corresponding to the transitions of Bi<sup>2+</sup> ions. The samples exhibited NIR persistent luminescence under 260 nm excitation, with the CaSnO<sub>3</sub>:5% Bi<sup>2+</sup> sample demonstrating the highest phosphorescence intensity and longest decay time. This optimal performance was attributed to the highest trap concentration, confirmed by thermoluminescence spectroscopy. The persistent NIR luminescence of the CaSnO<sub>3</sub>:Bi<sup>2+</sup> materials was attributed to trap level up-conversion, a phenomenon where NIR excitation leads to NIR emission without the involvement of up-conversion materials. This mechanism arises from the reverse carrier transition from deep traps (DTs) to shallow traps (STs). Thermoluminescence spectroscopy further confirmed the occurrence of trap level up-conversion in the CaSnO<sub>3</sub>:5% Bi<sup>2+</sup> sample. The successful synthesis and characterization of CaSnO<sub>3</sub>:Bi<sup>2+</sup>NIR long persistent luminescent materials with trap level up-conversion mechanisms opens up new avenues for their application in various fields.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 3-4","pages":"224 - 231"},"PeriodicalIF":0.9,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143109176","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}
Yu. M. Podrezov, V. M. Klymenko, V. I. Danilenko, M. V. Karpets, I. I. Ivanova
{"title":"High-Temperature Properties of Niobium- and Molybdenum-Doped γ-TiAl Powder Materials Produced Using Titanium Hydride","authors":"Yu. M. Podrezov, V. M. Klymenko, V. I. Danilenko, M. V. Karpets, I. I. Ivanova","doi":"10.1007/s11106-025-00448-6","DOIUrl":"10.1007/s11106-025-00448-6","url":null,"abstract":"<p>The creep-resistant γ-TiAl-based Ti<sub>46</sub>Al<sub>49</sub>Nb<sub>4</sub>Mo<sub>1</sub> alloy, with a composition close to that of the third- generation TNM alloy, was developed with the powder metallurgy method using titanium hydride and intermetallics as starting materials. The alloy had a duplex structure, with 20–25 μm grains, consisting of 22% α<sub>2</sub> phase and 78% γ phase. No additional phases were detected. Mechanical properties of the powder material at temperatures up to 850°C were studied by compression and bending tests. At a temperature of 20°C, the Ti<sub>46</sub>Al<sub>49</sub>Nb<sub>4</sub>Mo<sub>1</sub> alloy exhibited a bending strength of 800 MPa and significant high-temperature strength, remaining at a level of 670 MPa at 850°C. The alloy also showed enhanced creep resistance in compression tests, attributed to its fine-grained duplex structure. At temperatures up to 800°C, the alloy demonstrated considerably higher yield stress and strengthened more rapidly than the three-component material. Creep testing of the Ti<sub>46</sub>Al<sub>49</sub>Nb<sub>4</sub>Mo<sub>1</sub> alloy between 750 and 800°C indicated increased high-temperature creep resistance. The strain rate sensitivity remained unchanged at both 750°C and at 800°C under all applied loads, suggesting an invariant deformation mechanism. The calculated thermal activation parameters for creep were in good agreement with data for cast alloys of this class. The mechanical properties of the Ti<sub>46</sub>Al<sub>49</sub>Nb<sub>4</sub>Mo<sub>1</sub> alloy indicate its potential for use at temperatures up to 800°C.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 3-4","pages":"164 - 172"},"PeriodicalIF":0.9,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143109177","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":"Density Analysis on Circular High-Density Titanium Electrode Block Pressed by Segmented and Integral Method: A Simulation Report","authors":"Wei Zhang, Hao Chen, Lile He, Fazhan Wang, Guangyong Zhang","doi":"10.1007/s11106-025-00445-9","DOIUrl":"10.1007/s11106-025-00445-9","url":null,"abstract":"<p>This paper examines the relative merits of integral and traditional segmented compaction concerning three key aspects: uniformity of relative density, distribution of low-density areas, and the influence of loading mode on relative density. Under the actual operational conditions and anticipated dimensions of the final product, the initial dimensions of the material and the surface pressure applied before compaction are calculated. The average relative density and relative density distribution of circular titanium electrode blocks with different diameters (450, 500, and 550 mm) and different compaction processes were analyzed in the densification process. The impact of lubrication on the relative density distribution was investigated by modifying the coefficient of friction from 0.7 to 0.5, 0.3, and 0.1. The findings indicate that the electrode block's diameter significantly influences the relative density distribution. When the diameter exceeds 500 mm, it is imperative to pay particular attention to the low-density area (less than 0.7), which exhibits a notable increase from 0.42 to 1.71% in unidirectional compaction and from 0.02 to 0.18% in bidirectional compaction when the integral method is employed. Accordingly, the reduction in slag volume resulting from this factor should be considered when using the integral compaction method. In the case of electrode blocks with a diameter of 800 mm, the percentage of relative density between 0.7 and 0.8 under bidirectional compaction is higher than that under unidirectional one. However, the results were contrary in the range of 0.8 to 0.9. Compared to the integral method, the segmented method exhibited a comparable trend, with a percentage of relative density between 0.7 and 0.8, reaching 86.03% and a percentage of less than 0.7, equaling 0%. Furthermore, the core density of the segmented method is also higher than that of the integral one and has a standard deviation of approximately half that of the integral method. It indicates that in the case of uniform mixing, the uniformity of the segmented compaction is superior, and segregation is not readily produced. The standard deviation of the relative density distribution decreased with a reduction in the coefficient of friction, suggesting that the lubricant addition is beneficial in enhancing the uniformity of the density.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 3-4","pages":"128 - 143"},"PeriodicalIF":0.9,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108556","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}
V. P. Solntsev, G. A. Bagliuk, T. O. Solntseva, K. M. Petrash
{"title":"Thermal Processes in the Heating of Powder Compacts of Metals and Their Compositions III. Thermokinetics of Recrystallization Processes in the Heating of Compacts Produced from a Mixture of Aluminum and Iron","authors":"V. P. Solntsev, G. A. Bagliuk, T. O. Solntseva, K. M. Petrash","doi":"10.1007/s11106-025-00446-8","DOIUrl":"10.1007/s11106-025-00446-8","url":null,"abstract":"<p>The thermokinetics of recrystallization processes that occur during the heating of porous compacts, produced by cold pressing a mixture of ultrapure aluminum and iron powders in a 50: 50 ratio in a steel die, was experimentally studied. Over the 130–190°C temperature range, the aluminum component of the mixture undergoes relaxation, exhibiting wave-like behavior with a period of 0.2– 0.3 sec. Complete recrystallization occurs within the 165–235°C range. Subsequently, the relaxation process begins in the iron component of the mixture, with the initial stage characterized by nonlinear oscillations, transitioning to the next stage involving wave propagation of thermal energy. There are several periods of changes in wave propagation. The nonlinear wave-like rise in temperature during relaxation typically ends with another surge of energy release when the temperature rise period shortens, indicating more intense heat release. At its initial stage, the recrystallization process shows stationary linear behavior, which later transitions to the emergence of nonlinear waves. Changes in wave frequency are observed, along with intermittent wave behavior, suggesting the turbulence of thermal flows. Following this regime, the temperature increases up to the melting point of aluminum. However, complete melting does not occur because of crystallization within lower-temperature regions. All transitions marked by changes in thermokinetic paths at both relaxation and recrystallization stages are accompanied by bifurcation changes in the amplitude of the thermal waves.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 3-4","pages":"144 - 149"},"PeriodicalIF":0.9,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108493","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}
O. V. Dudnik, M. Yu. Smirnova-Zamkova, I. O. Marek, V. P. Redko, O. I. Khomenko, V. V. Gerashchenko, T. V. Mosina, O. K. Ruban
{"title":"Effect of Heat Treatment of the Starting Powders on the Consolidation of Zirconia-Toughened Alumina Composites","authors":"O. V. Dudnik, M. Yu. Smirnova-Zamkova, I. O. Marek, V. P. Redko, O. I. Khomenko, V. V. Gerashchenko, T. V. Mosina, O. K. Ruban","doi":"10.1007/s11106-025-00449-5","DOIUrl":"10.1007/s11106-025-00449-5","url":null,"abstract":"<p>The influence of heat treatment temperature of the starting powders, ranging from 400 to 1450°C, on the consolidation of zirconia-toughened alumina (ZTA) composites was studied. In these composites, particles of a ZrO<sub>2</sub> (Y<sub>2</sub>O<sub>3</sub>, CeO<sub>2</sub>) solid solution with high fracture toughness are dispersed in an Al<sub>2</sub>O<sub>3</sub> matrix. The powders for developing the ZTA composites (wt.%)—90 Al<sub>2</sub>O<sub>3</sub>–10 (ZrO<sub>2</sub> (Y<sub>2</sub>O<sub>3</sub>,CeO<sub>2</sub>) (90 AZK) and 70 Al<sub>2</sub>O<sub>3</sub>–30 (ZrO<sub>2</sub> (Y<sub>2</sub>O<sub>3</sub>,CeO<sub>2</sub>) (70 AZK)—were produced using a combination of hydrothermal synthesis and mechanical mixing. Cold uniaxial pressing and sintering in air at 1600°C for 1.5 h were employed for the consolidation. The sintered materials were examined by X-ray diffraction and scanning electron microscopy. The compaction of the composites was associated with the brittle fracture of hard sintered agglomerates (for 90 AZK) and with the plastic deformation effect (for 70 AZK). The sintering of the 90 AZK and 70 AZK composites was accompanied with ZrO<sub>2</sub> phase transformations, abnormal growth of the Al<sub>2</sub>O<sub>3</sub> grains, and zonal segregation effect. The Zener pinning effect in the 70 AZK composites inhibited the abnormal growth of Al<sub>2</sub>O<sub>3</sub> grains. The increased porosity of the 90 AZK composites was due to the bimodal distribution of the starting powder agglomerates in accordance with the shape factor. The Vickers hardness of the 90 AZK samples varied from 6.4 to 4.4 GPa and that of the 70 AZK samples from 10.3 to 7.2 GPa. The decreased hardness of the 90 AZK composites was attributed to the formation of a two-scale porous microstructure. The topological memory of the ceramics was demonstrated to determine the conditions for microstructural design of advanced ZTA composites for tool, structural, and functional purposes with the required properties.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 3-4","pages":"173 - 183"},"PeriodicalIF":0.9,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108560","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":"Friction Stir Spot Welding and Characterization of Bulk Aluminum Alloy 6061 Synthesized Using Powder Metallurgical Route","authors":"Ravindra Singh Shekhawat, Vijay Navaratna Nadakuduru","doi":"10.1007/s11106-025-00456-6","DOIUrl":"10.1007/s11106-025-00456-6","url":null,"abstract":"<p>Powder metallurgy (PM) is a manufacturing approach that enables the production of complex shapes with minimal waste. This approach allows for creating intricate and readily deployable components, often surpassing the capabilities of traditional casting and metal forming techniques. The present study explores the feasibility of employing friction stir spot welding (FSSW) to join aluminum alloy 6061 (AA6061) components fabricated using the PM route. The research involves fabricating AA6061 samples employing the PM process. The sintering process involved induction heating at 530–550°C, followed by hot forging, ensuring optimal densification. FSSW was applied to both PM-processed and conventionally wrought AA6061 samples using three welding parameters. Comparative evaluations focused on the resulting welds’ microstructural characteristics and mechanical properties. Microstructural analysis revealed that PM-fabricated samples exhibited finer grain structures and superior hardness within the weld zones than their wrought counterparts. Furthermore, the thermomechanically affected zone (TMAZ) was narrower in PM-processed joints, indicating enhanced mechanical properties and a more uniform microstructure. The hardness values witnessed in the FSSW of the PM-processed Al 6061 point to the formation of superior-quality joints when compared to FSSW-welded sections of sheets produced through conventional means. This study highlights the potential of PM-fabricated AA6061 for advanced welding applications, demonstrating notable improvements in microstructural refinement and joint quality, integrating PM techniques with advanced welding processes to overcome traditional manufacturing limitations.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 3-4","pages":"240 - 249"},"PeriodicalIF":0.9,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143108492","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":"Grain Coarsening Kinetics and Strength Modeling of Fe–15Cr–2W Oxide Dispersion Strengthened Steels with Varying Yttria Contents","authors":"Lekhraj Verma, Vikram V. Dabhade","doi":"10.1007/s11106-024-00437-1","DOIUrl":"10.1007/s11106-024-00437-1","url":null,"abstract":"<p>15 Cr ferritic oxide dispersion strengthened (ODS) steels are considered prime fuel cladding materials in nuclear reactors due to their excellent creep, swelling, and oxidation resistance. In the present study, the nominal compositions Fe–15Cr–2W–xY<sub>2</sub>O<sub>3</sub> (x = 0, 0.3, 0.7, and 1.0) of ferritic ODS steels were prepared by mechanical alloying followed by spark plasma sintering. The sintered samples were annealed at different temperatures of 950, 1100, and 1250°C with a holding time of 60 min at respective temperatures. Further, the samples were also annealed at 1100°C for various durations of 0, 60, and 120 min. The role of varying yttria dispersoids and annealing temperatures on the grain growth kinetics, as well as their mechanical properties (hardness and compressive strength), were analyzed. The compressive strength of the sintered samples with varying yttria contents and at elevated temperatures of 600 and 700°C was determined. Modeling of compressive yield strength at room and elevated temperatures, as well as a correlation with the experimental values, were established for all the compositions. The grain growth exponent (n) and activation energy (Q) rose with the increase in yttria content and were estimated to be 11.52 and 612.91 kJ/mol, respectively, with 1.0 wt.% yttria. The grain size was nearly stable at the annealing temperature of 1100°C. A significant rise in compressive strength at room temperature and elevated temperatures was observed with a yttria reinforcement content of 0.7 wt.%. According to the strength model at different conditions, the role of ultrafine grains and dispersoids seemed to be predominant at room temperature and high temperatures, respectively.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 1-2","pages":"37 - 59"},"PeriodicalIF":0.9,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142565950","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":"Structural Features of the Cr3C2–NiCr and Ni–Cr–Fe–B–Si Coatings Produced by Multichamber Detonation Spraying","authors":"V.M. Korzhyk, O.M. Berdnikova, P.D. Stukhliak, O.S. Kushnarova, O.V. Kolisnichenko, I.O. Skachkov, Ye.P. Titkov","doi":"10.1007/s11106-024-00442-4","DOIUrl":"10.1007/s11106-024-00442-4","url":null,"abstract":"<p>The detonation spraying of coatings from fine composite materials is analyzed in the paper. The use of detonation coatings was found to improve the properties of machines and mechanisms and extend their life, while their functional performances are maintained over long-term operation. The structural features, strength, and fracture toughness of the coatings produced by multichamber detonation spraying from 75 wt.% Cr<sub>3</sub>C<sub>2</sub> + 25 wt.% NiCr and Ni–Cr–Fe–B–Si (77–81.5 wt.% Ni, 10–14 wt.% Cr, 5–7 wt.% Fe, 2.0–2.3 wt.% B, 2.0–3.2 wt.% Si, 0.5 wt.% C) powder materials were examined. Changes in the detonation spraying parameters were proved to significantly influence the structure of the coatings: microhardness, phase composition, volume content of lamellae, sizes of grains and subgrains, phase formation, and dislocation density. The structural and phase state of the coatings was studied at all structural levels using a comprehensive approach, involving light and scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The prospects of the multichamber detonation spraying method, ensuring the necessary combination of structural and phase parameters of the coating material with a simultaneous increase in their physical, mechanical, and operational properties, were demonstrated. A high level of strengthening and fracture toughness of the coatings was promoted by optimal structural and phase constituents: fine grain and subgrain structure, uniform distribution of nanosized strengthening particles, and uniform dislocation density. The improved fracture toughness of the coatings is due to the absence of extended structural areas of dislocation clusters. The gradient-free distribution of dislocation density prevents the formation of local internal stress concentrators in the resulting coatings.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 1-2","pages":"107 - 116"},"PeriodicalIF":0.9,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142565952","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}
L. I. Adeeva, A. Yu. Tunik, V. M. Korzhyk, D. V. Strogonov, V. A. Kostin, O. V. Konoreva
{"title":"Properties of Powders Produced by Plasma-Arc Spheroidization of Current-Carrying Fe–Al Flux-Cored Wire","authors":"L. I. Adeeva, A. Yu. Tunik, V. M. Korzhyk, D. V. Strogonov, V. A. Kostin, O. V. Konoreva","doi":"10.1007/s11106-024-00434-4","DOIUrl":"10.1007/s11106-024-00434-4","url":null,"abstract":"<p>The powders produced by plasma-arc wire atomization in an argon atmosphere or air were studied for their use in 3D printing of complex-shaped metal parts and in granular metallurgy. The dependence of the morphology, structure, phase composition, and microhardness of the powders on the current and atomization conditions was established. In all studied operating modes of the plasma torch (180, 220, and 270 A), the atomized particles are predominantly spherical. The number of nonspherical particles increases with particle size. The powders atomized in an argon atmosphere exhibit a stable phase composition. The main component is iron aluminide Fe<sub>3</sub>Al (or a mixture of Fe<sub>3</sub>Al and AlFe). The α-Fe, Fe<sub>3</sub>O<sub>4</sub>, and Fe<sub>2</sub>O<sub>3</sub> phases were also found. At currents of 220 and 270 A, the powder in –200+100 μm fraction contains the highest amount of aluminides, 83.88 and 86.30 wt.%, and the lowest content of oxides, 6.61–10.18 wt.%. In fine powders (–100+75 μm), the content of aluminides is 70.38– 28.3 wt.%), but the amount of oxides increases to 23.32–29.62 wt.%. The microhardness of oxide particles (5320–8150 MPa) is higher than that of metal particles (3070–4590 MPa). In atomization in air, the key components are Fe<sub>2</sub>O<sub>3</sub>, Fe<sub>3</sub>O<sub>4</sub>, FeO, and Al<sub>3</sub>O<sub>4</sub>. The total amount of oxides reaches 57.19–90.34%. The percentage of iron aluminides decreases significantly, and their maximum content (28.3 wt.%) is shown by the –315+200 μm powder at a plasma torch current of 270 A. In the finest powder fraction of –100+75 μm, the content of aluminides ranges from 6.2 to 15.36 wt.%. The average microhardness of metal particles is much lower (2750–4940 MPa) than that of oxide particles (4500–7460 MPa). It was found that the best material in terms of phase composition, structure, hardness, and shape factor was produced by atomization of a flux-cored wire in an argon atmosphere. In atomization in air, intense oxidation processes occur.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 1-2","pages":"12 - 23"},"PeriodicalIF":0.9,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142565769","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}
V. D. Klipov, V. P. Serhieiev, O. R. Parkhomey, O. M. Budylina, L. S. Protsenko
{"title":"Production of Pressed Porous Glass-Ceramic Carbon Fiber Biocomposites for Medical Applications","authors":"V. D. Klipov, V. P. Serhieiev, O. R. Parkhomey, O. M. Budylina, L. S. Protsenko","doi":"10.1007/s11106-024-00440-6","DOIUrl":"10.1007/s11106-024-00440-6","url":null,"abstract":"<p>Pressed porous glass-ceramic carbon fiber biocomposites were produced from hydroxyapatite/glass and nanostructured carbon fibers. The specific features of the production process, as well as the composition, macrostructure, microstructure, and porosity of these biocomposites, were studied. The prospects for their medical applications, particularly in surgical osteoplasty, were identified. The starting materials included calcium phosphate glass ceramics derived from biogenic hydroxyapatite, featuring both bound and migrating glass phases, and activated nanostructured carbon fibers. The glass ceramics with a bound glass phase were produced by sintering powder mixtures of biogenic hydroxyapatite and sodium borosilicate glass, while those with a migrating glass phase were produced through mechanical mixing of biogenic hydroxyapatite and sodium borosilicate glass powders. The fine activated nanostructured carbon fibers used in the biocomposites were obtained by the mechanical grinding of a woven material from activated nanostructured carbon fibers. This material resulted from the controlled stepwise pyrolysis of hydrocellulose fabrics, followed by high-temperature vapor activation of the nanostructured fiber surface. To make cylindrical biocomposite samples, the fine activated nanostructured carbon fibers were blended with moistened mixtures of biogenic hydroxyapatite glass ceramics with bound and migrating glass phases and subjected to semidry pressing and incremental sintering with holding at 800°C. The selected process parameters enabled the production of pressed carbon fiber biocomposites with the desired composition and showed the ability to control their porous structure, achieving a relative density of 0.36–0.41, by regulating the behavior of the glass phases and the sintering of the reinforcing component. The biocomposite structures were examined by scanning electron microscopy. Energy-dispersive X-ray analysis was conducted to determine the chemical composition of the samples. The structures of the composites were analyzed and compared on the basis of their sorption capacities, determined from benzene adsorption–desoprtion isotherms using the gravimetric method. Analysis of the macrostructure, microstructure, and surface morphology of transverse and longitudinal sections of the biocomposites revealed a multiporous amorphous-crystalline microstructure, arising from the varying behavior of the glass phases, the presence of chaotically oriented short fine nanostructured carbon monofibers with diameters of several microns and a developed system of micro- and macropores on their surface, and spatial multidirectional hollow channels formed through the complete or partial combustion of the fibers.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 1-2","pages":"82 - 94"},"PeriodicalIF":0.9,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142565951","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}