Powder Metallurgy and Metal Ceramics最新文献

{"title":"Influence of Cr Addition on the Microstructure and Mechanical Properties of WCoB–TiC Ceramic Composites","authors":"Deqing Ke,&nbsp;Linhao Du,&nbsp;Wei Wang,&nbsp;Yingjun Pan,&nbsp;Junkai Wang","doi":"10.1007/s11106-025-00470-8","DOIUrl":"10.1007/s11106-025-00470-8","url":null,"abstract":"<p>In this study, the mechanical and electronic properties of W₂CoB₂ hard phases in the WCoB–TiC ceramic composites with varying Cr contents were analyzed using first-principles calculations. Experimental measurement was conducted to determine the microstructure, hardness, transverse rupture strength (TRS), and fracture toughness (<i>K</i>_Ic) of WCoB–TiC ceramic composites with different Cr contents. First-principles calculations showed that adding a small amount of Cr could increase the bulk elastic modulus of the material. However, as the concentration of Cr increased, its bulk elastic modulus decreased. Moreover, it was found that Cr doping effectively enhanced the material's toughness, which might be attributed to strengthening the covalent bond property of the B–Cr chemical bond with higher Cr doping concentrations. The experimental results indicated that Cr doping reduced the density of Cubatic ceramic composites. Still, a small amount of Cr could refine the grain size of the hard phases, thereby enhancing the overall mechanical properties of the composites. The WCoB–TiC ceramic composites achieved the highest hardness, TRS, and <i>K</i>_Ic values of 92.3 HRA, 906.5 MPa, and 12.45 MPa ∙ m^1/2, respectively, at a Cr content of 2.0 wt.%.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 7-8","pages":"382 - 395"},"PeriodicalIF":0.6,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145143550","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":"Solid-State Reactions and Phase Relationships in the Quinary SiC–SiO2–TiC–TiO2–CaO and Boundary SiC–CaO–TiO2 Systems at 1400°C","authors":"W. Z. Sun,&nbsp;Z. K. Huang,&nbsp;Y. J. Lu,&nbsp;L. M. Liu,&nbsp;X. P. Zhang","doi":"10.1007/s11106-025-00475-3","DOIUrl":"10.1007/s11106-025-00475-3","url":null,"abstract":"<p>It is known that TiC can be formed as a result of solid-phase reactions in SiC–TiO₂–CaO systems. To synthesize TiC-based ceramics or SiC/TiC multiphase ceramics using this reaction, it is first necessary to research the high-temperature physicochemical reactions and phase equilibrium relationships within the reaction system, which will serve as the basis for formulation optimization and process guidance. Therefore, solid-state reactions and phase equilibrium relations in the quinary SiC–SiO₂–TiC–TiO₂–CaO system and its boundary SiC–TiO₂–CaO system at 1400°C were investigated through experiments and thermodynamic calculations. The results suggest that the system undergoes numerous high-temperature physicochemical reactions. First, TiO₂ reacted with SiC to form TiC through a displacement reaction: TiO₂ + SiC = TiC + SiO₂. Then, SiO₂ immediately reacted with CaO, forming calcium silicates such as CaSiO₃, Ca₃Si₂O₇, Ca₂SiO₄, or Ca₃SiO₅. At the same time, excess TiO₂ and CaO react to form calcium titanates, such as CaTiO₃, Ca₃Ti₂O₇, or CaTiSiO₅. Experiments confirmed the equilibrium relations of TiC with salt-like compounds in the oxide SiO₂–TiO₂–CaO system, except for CaTiSiO₅, which was not obtained due to the reduction of TiO₂ in the samples, resulting in the formation of Ca₃Ti₂Si₃O₁₂ and Ti₂O₃. Upon meticulous examination of the phase relationships within the SiC–SiO₂–CaO ternary system, it has been conclusively demonstrated that SiC coexists in equilibrium with all calcium silicate salts. The binary, ternary, and quaternary phase relationships within the system were successfully determined, and based on this, a tentative scheme of phase relationships in the SiC–SiO₂–TiC–TiO₂–CaO system was established. There are seven TiC-containing four-phase regions and six SiC/TiC-containing four-phase regions. These works would benefit compositionally designing MC ceramic and MC/SiC composites.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 7-8","pages":"444 - 454"},"PeriodicalIF":0.6,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145143549","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 the Production Parameters on Structural Features and Mechanical Properties of Multicomponent Creep-Resistant Niobium-Based Alloy","authors":"G. A. Bagliuk,&nbsp;M. V. Marych,&nbsp;M. P. Brodnikovsky,&nbsp;T. L. Kuznetsova,&nbsp;O. A. Rokitska,&nbsp;S. A. Kulakov","doi":"10.1007/s11106-025-00469-1","DOIUrl":"10.1007/s11106-025-00469-1","url":null,"abstract":"<p>The effect of key process parameters on the structural features and mechanical properties of the multicomponent creep-resistant 57Nb–10Cr–5Al–21Ti–7Mo (at.%) alloy produced by powder metallurgy methods from a mixture of elemental metal powders was studied. The production process included consolidation of the powder mixtures, part of which underwent mechanical activation in a planetary mill with subsequent hot forging. Some of the hot-forged samples were annealed in a vacuum furnace at 1600°C. The hot-forged materials exhibited a heterogeneous structure, consisting of a solid-solution matrix based on the Nb–Mo system and evenly distributed grains of an intermetallic phase based on the Ti–Al system, and were characterized by pronounced anisotropy. A gradient distribution of Al and Nb within the titanium grains after hot forging was revealed. Annealing at 1600°C altered the grain morphology and resulted in near-complete homogenization of the alloy with the formation of a single-phase bcc structure. The highest mechanical properties at room temperature and 600°C were observed for the materials produced by hot forging of a powder mixture ground for 30–60 min. At 1000°C, the yield stress of the alloy annealed at 1600°C exceeded σ_0.2 of the hot-forged alloys not subjected to annealing and reached the level of the as-cast alloy of the same composition.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 7-8","pages":"372 - 381"},"PeriodicalIF":0.6,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145143466","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":"Advanced Approaches for Producing Nanocrystalline and Fine-Grained ZrO2-Based Powders(Review) II. Wet Chemistry Methods: Coprecipitation, Sol–Gel Process, and Pechini Method","authors":"O. V. Dudnik,&nbsp;S. M. Lakiza,&nbsp;I. O. Marek,&nbsp;V. P. Red’ko,&nbsp;A. O. Makudera,&nbsp;O. K. Ruban","doi":"10.1007/s11106-025-00474-4","DOIUrl":"10.1007/s11106-025-00474-4","url":null,"abstract":"<p>This part of the review focuses on wet chemistry methods that do not involve pressure effects on the starting components. The features of synthesizing nanocrystalline powders of both unstabilized ZrO₂ and ZrO₂-based systems are described. Under precipitation, the synthesis completeness and physicochemical properties of the powders depend on the concentration of reagents, pH of the environment, precipitate washing quality, and drying methods. For deagglomeration of powders, high-energy grinding in ball mills, azeotropic distillation in an aliphatic alcohol environment with more than three carbon atoms, ultrahigh-frequency radiation, pulsed magnetic field, and their combinations with ultrasonic treatment in the powder synthesis process are employed. Coprecipitation using microemulsions was developed to produce powders with spherical particle morphology. The sol–gel process relies on polycondensation and hydrolysis processes and is believed to be a simple method to synthesize homogeneous powders of complex composition. The use of microwave heating in the powder sol-gel synthesis process and the influence of synthesis conditions on powder sinterability are shown. The preparation of mesoporous ZrO₂-based materials, which are promising for the development of catalysts for their special structural characteristics, is considered. The Pechini method (citrate method and polymer complex method) is used to synthesize highly homogeneous and superfine oxide materials, employing complexation and intermediate preparation of a polymer gel. The properties of powders produced through various modifications of the Pechini method are compared. The potential for producing nanosheets is shown. Zirconia-based powders synthesized with the discussed methods were used in the development of sorbents and photocatalysts, solid oxide fuel cells, various optical materials, advanced thermal barrier coatings, nanofiltration membranes, nanostructured amorphous composites with high strength, and functional materials for medical applications, particularly for diagnosis and therapy.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 7-8","pages":"426 - 443"},"PeriodicalIF":0.6,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145143465","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":"Microstructural Evolution and Dry Sliding Wear Properties of Doping W in Ti–10 vol.% TiC Composite Foams","authors":"Feng Zhao,&nbsp;Yunfeng Zhang,&nbsp;Rongyue Ge,&nbsp;Binna Song","doi":"10.1007/s11106-025-00468-2","DOIUrl":"10.1007/s11106-025-00468-2","url":null,"abstract":"<p>Herein, novel Ti–TiC(W) composite foams were designed to address the low wear resistance of porous Ti-based alloys. Inexpensive TiH₂ was used instead of Ti powder, and the Ti–10 vol.% TiC matrix was doped with 1 vol.% nanoscale W powder, using 40 vol.% NaCl as the spacer. Ti–TiC(W) composite foams were fabricated through spark plasma sintering, dissolution, and post-heat treatment (PHT) at 900 and 1200°C for 1 h. The influence of W doping on the microstructure and tribological properties of the composite foams before and after PHT was investigated. After posttreatment, the material matrix relative density exceeded 0.9686, with a maximum microhardness of 582.36 HV_0.2 at a PHT temperature of 1200°C. After PHT at 900°C, the W particles gradually diffused into the Ti matrix, forming a diffusion zone. However, some W particles remained undissolved at the center of the diffusion zone, forming a Ti–W corona. After PHT at 1200°C, W formed a uniform mesh structure in the matrix, significantly enhancing the density and microhardness of the matrix by strengthening the strength of precipitation. The coefficients of friction of the materials ranged from 0.1565 to 0.2234, with mild wear observed after PHT at 1200°C and a minimum wear rate of 0.27 ∙ 10^–12 m³· N^–1 ∙ m^–1. The network precipitated phasesynergized to inhibit the formation of wear marks, significantly improving wear resistance. This strategy can enhance the wear resistance of porous Ti-based materials.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 7-8","pages":"362 - 371"},"PeriodicalIF":0.6,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145143214","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":"Evolution of the Compaction Process and Stress–Strain State of Porous Billets During Hot Forging in Dies with a Double-Sided Conical Flash Gutter","authors":"G. A. Bagliuk,&nbsp;S. F. Kyryliuk","doi":"10.1007/s11106-025-00467-3","DOIUrl":"10.1007/s11106-025-00467-3","url":null,"abstract":"<p>Hot forging of a porous billet in a semi-closed die with a double-sided conical flash gutter was modeled using the finite element method with the DEFORM 2D/3D software package. Analysis of the modeling results identified three consecutive stages of the process, driven by variations in the stress–strain state of the forged workpiece. A significant uneven distribution of axial and radial strains over the workpiece cross-section was established at different stages of the process. At the initial stage, the density distribution over the forged material was characterized by significantly higher values in the central region of the forged workpiece compared to the peripheral areas. However, after the die cavity was filled, the material density averaged over the workpiece cross- section. At the final forging stage, the entire volume of the forged workpiece was compacted to an almost nonporous state. This indicated that the axial component significantly influenced the compaction process at the initial and intermediate forging stages. Nevertheless, after the die cavity was filled, intense flow was observed predominantly in the radial direction, and therefore the radial strain component directly influenced the compaction process. The effective stress distribution, closely correlating with the relative density distribution over the workpiece cross-section at the initial and intermediate forging stages, changed after the die cavity was filled and the excess material was extruded into the flash gutter.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 7-8","pages":"353 - 361"},"PeriodicalIF":0.6,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145142729","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":"Influence of AlB12 Particles on the Strengthening Effect in Aluminum Matrix Composites","authors":"M. O. Iefimov,&nbsp;V. A. Goncharuk,&nbsp;V. V. Kuprin,&nbsp;N. P. Zakharova,&nbsp;V. B. Muratov","doi":"10.1007/s11106-025-00472-6","DOIUrl":"10.1007/s11106-025-00472-6","url":null,"abstract":"<p>The structure and mechanical properties of Al–AlB₁₂ powder composites were studied. Composites containing 2.5, 5, 10, and 15 vol.% α-AlB₁₂ particles in an aluminum matrix were produced by heating and melting a mixture of Al and α-AlB₁₂ powders using a high-frequency heating unit in an inert atmosphere at 1250–1500°C. The melt temperature was increased with higher α-AlB₁₂ content to maintain the required melt fluidity. Aluminum powder with an average particle size of 40 μm and α-AlB₁₂ powder with an average particle size of 2.5 μm were used to produce the composites. The structure was analyzed with X-ray diffraction and scanning electron microscopy. The mechanical properties were determined through compression testing. X-ray diffraction and metallographic analyses revealed that all composites represented an aluminum matrix reinforced with finely dispersed α-AlB₁₂ particles. Metallographic analysis demonstrated uniform distribution of strengthening α-AlB₁₂ particles in the aluminum matrix at 2.5–5 vol.% content. Inhomogeneous particle distribution, with the formation of α-AlB₁₂ agglomerates, was observed at 10 and 15 vol.% α-AlB₁₂. In the composites with 2.5, 5, and 10 vol.% α-AlB₁₂, the integral hardness ranged from 510 to 570 MPa. The hardness of the Al–15 vol.% AlB12 composite was 540 MPa. Mechanical tests of the composites with 2.5 and 5 vol.% α-AlB₁₂ phase revealed their precipitation strengthening, which was well described by a modified Orowan equation. In the composite with 10 vol.% α-AlB₁₂ particles and above, the strengthening effect was diminished, and even softening occurred in the composite with 15 vol.% α-AlB₁₂ particles. This was attributed to the formation of a large number of α-AlB₁₂ particle agglomerates. The minimum content of α-AlB₁₂ particles promoting the precipitation strengthening in Al–AlB₁₂ composites was estimated. Considering the calculation error, it was 1 vol.%.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 7-8","pages":"410 - 416"},"PeriodicalIF":0.6,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145142718","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":"Discharge Capacity and Corrosion Resistance of Composite Electrodes Produced from ZrNi1.2 Mn0.5Cr0.2V0.1 and Copper Powders","authors":"Yu. M. Solonin,&nbsp;O. Z. Galiy,&nbsp;K. O. Graivoronska,&nbsp;A. V. Samelyuk","doi":"10.1007/s11106-025-00473-5","DOIUrl":"10.1007/s11106-025-00473-5","url":null,"abstract":"<p>Two samples of the ZrNi_1.2Mn_0.5Cr_0.2V_0.1 alloy were prepared using argon-arc melting. The samples differed in weight, resulting in distinct cooling modes, and their quantitative phase composition was determined with X-ray diffraction. The electrochemical properties of the alloy samples and the associated composite with a copper addition (in a 1 : 1 alloy-to-copper weight ratio) were studied in both potentiodynamic and galvanostatic modes in the cathodic and anodic potential regions. In particular, the hydrogen capacity and corrosion resistance of the samples discharged to a voltage of 0.7 V relative to the Ni(OH)₂ electrode (~0.4 V relative to the Hg/HgO electrode) were evaluated. In discharge to 0.7 V, the activation of the ZrNi_1.2Mn_0.5Cr_0.2V_0.1 alloy electrodes accelerated as compared to 0.8 V and thus the discharge capacity in the first hydrogenation–dehydrogenation cycles increased significantly, while the maximum achieved discharge capacity of the composite depended on the number of Laves phases in the alloy. At 20°C, the composite produced from the alloy with higher Laves phase content (~90 vol.% C₁₄₊₁₅) activated three to four cycles sooner than the sample with a lower Laves phase content (~80 vol.% C₁₄₊₁₅) and achieved a higher discharge capacity of ~290 mA· h/g when discharged to 0.8 V. The discharge capacity of the composite discharged to 0.7 V relative to the Ni(OH)₂ electrode (~0.4 V relative to the Hg/HgO electrode) combined the contribution from the alloy via electrochemical hydrogenation–dehydrogenation processes and the contribution from copper via oxidation with anodic polarization. The passivation region on the corrosion curve over a wide range from the stationary potential to E = +0.5 V for the alloy section processed in 30% KOH solution demonstrated the corrosion resistance of the alloy electrodes at a discharge voltage of –0.7 V, indicating the absence of selective dissolution of alloy components.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 7-8","pages":"417 - 425"},"PeriodicalIF":0.6,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145142717","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":"Mechanical and Dielectric Properties of Si3N4-Based Ceramics","authors":"M. V. Zamula,&nbsp;V. G. Kolesnichenko,&nbsp;A. V. Stepanenko,&nbsp;N. I. Tyschenko,&nbsp;O. V. Shyrokov,&nbsp;V. V. Khardikov,&nbsp;D. M. Demirskyi,&nbsp;O. O. Vasylkiv,&nbsp;H. Y. Borodianska,&nbsp;A. V. Ragulya","doi":"10.1007/s11106-025-00464-6","DOIUrl":"10.1007/s11106-025-00464-6","url":null,"abstract":"<p>The effect of sintering-activating Y₂O₃ and SiO₂–Y₂O₃ additives on the mechanical and dielectric properties of Si₃N₄ and Si₃N₄–BN ceramics consolidated by spark plasma sintering was examined. The heating rate and applied pressure were maintained at 50°C/min and 35 MPa, respectively. The holding time at a sintering temperature of 1800°C varied depending on the composition of the oxide additives. The Si₃N₄–BN ceramics with Y₂O₃–SiO₂ additives exhibited a 30% reduction in mechanical properties (hardness and fracture toughness) compared to Si₃N₄–Y₂O₃ or Si₃N₄–Y₂O₃–SiO₂ ceramics. The Si₃N₄ ceramics demonstrated resistance to deformation at temperatures ranging from 20 to 900°C. Specifically, Si₃N₄ ceramics with Y₂O₃ or Y₂O₃–SiO₂ additives showed average strengths of approximately 950 and 820 MPa, whereas Si₃N₄–BN ceramics demonstrated a strength of 490 MPa. An increase in temperature from 1000 to 1400°C for all ceramics studied resulted in a gradual decrease in bending strength to approximately 200 MPa. The strength at room and elevated temperatures, Vickers hardness of approximately 4 GPa and 15.5 GPa, and fracture toughness of about 7.7 MPa · m^1/2 meet the current requirements for this type of ceramics. Radiofrequency measurements showed that dense Si₃N₄-based ceramics had a dielectric constant of 8. When 10 wt.% BN was added, the dielectric constant of the composite decreased by approximately 8%. Additionally, residual porosity of about 10% further decreased the dielectric constant of the Si₃N₄–BN composite by around 13% (ε ~ 6.3). This reduction in the dielectric constant had a positive effect on radio transparency. The dielectric loss tangent of the test ceramics did not exceed 2 · 10^–3.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 5-6","pages":"308 - 317"},"PeriodicalIF":0.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801209","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":"Thermal Processes in the Heating of Powder Compacts of Metals and Their Compositions IV. Thermokinetics of Recrystallization and Interaction Processes in the Heating of Compacts Produced from a Mixture of Aluminum and Iron Powders","authors":"V. P. Solntsev,&nbsp;G. A. Bagliuk,&nbsp;T. O. Solntseva,&nbsp;K. M. Petrash","doi":"10.1007/s11106-025-00462-8","DOIUrl":"10.1007/s11106-025-00462-8","url":null,"abstract":"<p>The thermokinetics of recrystallization and interaction processes in the heating of porous compacts produced from a mixture of ultrapure aluminum and iron in a 20 : 80 ratio after cold pressing in a steel die was studied using direct thermal analysis. Recrystallization of the aluminum component and relaxation of the iron component were observed in the temperature range 170–265°C. The iron relaxation and recrystallization exhibited a wavelike behavior. The iron component recrystallized completely in the temperature range 500–700°C. The interaction between aluminum and iron initiated with a reduction reaction through a small amount of surface iron oxides. The reduction of surface iron oxides, involving insignificant heat release, occurred in two stages, reflecting the existence of several iron oxides. Active interaction commenced at the melting point of aluminum. A cascade of exothermic effects, attributed to the interaction of intermetallic compounds with lower stoichiometries, was revealed. In this case, temperature exceeded the existence of the intermetallics, leading to their decomposition and subsequent cooling through the endothermic effect. The cooling rate during the decomposition of intermetallics closely resembled the rate of reaction synthesis. When the nonequilibrium solid solution cooled within the temperature range 500–600°C, the ironbased solid solution decomposed and the intermetallic compound synthesized. Thermokinetic oscillations emerge and gradually subside. At all stages of transitions from stationary states to temperature surges or drops, thermokinetic oscillations with varying frequencies and amplitudes were observed.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 5-6","pages":"292 - 297"},"PeriodicalIF":0.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801269","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}