Powder Metallurgy and Metal Ceramics最新文献

{"title":"Effect of Nickel-clad Graphite Additions on the Structure, Tribological Properties, and Friction Mechanism of Plasma-sprayed Brass–nickel-clad Graphite Composite Coatings","authors":"O. V. Kushchev,&nbsp;O. P. Umanskyi,&nbsp;O. Ye. Terentiev,&nbsp;V. T. Varchenko,&nbsp;O. A. Bondarenko,&nbsp;V. P. Konoval,&nbsp;M. S. Ukrainets","doi":"10.1007/s11106-026-00540-5","DOIUrl":"10.1007/s11106-026-00540-5","url":null,"abstract":"<p>Plasma-sprayed brass and brass–nickel-clad graphite composite coatings were developed and examined to improve the operational reliability of friction units operating under dry sliding conditions. The research focused on brass-based composite systems under dry friction against R18 steel. The initial brass coatings exhibited a friction coefficient of about 0.26 and a linear wear rate of 17.3 μm/km. The addition of nickel-clad graphite to the brass-based plasma coatings significantly enhanced their antifriction properties. With 10–30 wt.% nickel-clad graphite, the friction coefficient decreased to 0.20–0.19 and the linear wear to 5.2–4.7 μm/km. The optimal tribological properties of the brass–nickel-clad graphite/R18 steel friction pair were achieved at 50 wt.% nickel-clad graphite, resulting in a linear wear of 3.3 μm/km and a friction coefficient of 0.17. The improvement in tribological properties of the friction pair was attributed to the formation of graphite-containing secondary layers on the counterface. In the friction process, these layers acted as a solid lubricant. This was confirmed by microstructural and spectroscopic analyses. The experimental results demonstrated that the addition of nickel-clad graphite into brass-based plasma composite coatings was an effective approach to enhancing their antifriction properties.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 7-8","pages":"475 - 482"},"PeriodicalIF":0.6,"publicationDate":"2026-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147865711","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 ZrO2 Reinforcement on Microstructure and Mechanical Behaviour of Magnesium Composites Synthesized by Powder Metallurgy","authors":"M. Thilak,&nbsp;S. Jayasathyakawin,&nbsp;M. Ravichandran,&nbsp;G. Paulraj","doi":"10.1007/s11106-026-00538-z","DOIUrl":"10.1007/s11106-026-00538-z","url":null,"abstract":"<p>The present investigation is devoted to developing magnesium (Mg) matrix composites reinforced with zirconium dioxide (ZrO₂) at concentrations of 2, 4, and 6 wt.% via powder metallurgy (PM). While magnesium composites are promising for lightweight and biomedical applications, their rapid corrosion and reduced mechanical strength remain challenging due to inconsistent bonding between the reinforcement and the base matrix. Every composite specimen had been subjected to ball-milling in a cylindrical planetary ball mill at a speed of rotation of 120 rpm for a duration of 3 hours. Using a hydraulic press, the ball-milled powders were compressed. These compacts were then sintered in an argon atmosphere maintained at 400°C. The ball-milled powders were examined by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The XRD analysis of the ball-milled powders confirmed the absence of intermetallic compounds. The sintered composite materials were evaluated for microhardness and compressive strength (CpS). For the 6 wt.% ZrO₂ sample, compressive strength peaked at 157 MPa and hardness reached 57.9 HV, the highest values recorded. This composition also yielded the lowest corrosion rate (0.065 mm/year).</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 7-8","pages":"455 - 466"},"PeriodicalIF":0.6,"publicationDate":"2026-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147865654","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":"Microstructure and Wear Resistance of Plasma-sprayed and Detonation-sprayed (TiCrC)Ni Composite Coatings","authors":"O.Ye. Terentiev,&nbsp;V.P. Konoval,&nbsp;R.E. Kostyunik,&nbsp;O.V. Kushchev,&nbsp;K.N. Galtsov,&nbsp;O.A. Bondarenko,&nbsp;O.P. Umanskyi","doi":"10.1007/s11106-026-00539-y","DOIUrl":"10.1007/s11106-026-00539-y","url":null,"abstract":"<p>The microstructure and wear resistance of thermal spray composite coatings produced from nickel-clad titanium–chromium carbide ((TiCrC)–33 wt.% Ni) by plasma and detonation spraying were examined. The microstructure of the plasma-sprayed and detonation-sprayed coatings was multiphase and consisted of a nickel-based metal matrix with uniformly distributed grains of complex titanium and chromium carbides. The microhardness of the dark gray carbide phase was 24 GPa in the plasma-sprayed coatings and 21.6 GPa in the detonation-sprayed coatings. To evaluate wear resistance, flat samples with plasma-sprayed and detonation-sprayed (TiCrC)Ni composite coatings were produced. For comparison, reference samples were prepared from the industrial KKhN-35 material (65 wt.% Cr₃C₂–35 wt.% NiCr) and from ShKh15 steel (equivalents: G52986 in the USA, 1.3505 in the EU, and 100Cr6 in France) with 58–63 HRC hardness. To evaluate wear rate, a method for rapid testing of coatings by dry friction using the ASK-01 system was developed and tested. The friction test unit simulated sliding friction of a ShKh15 steel counterface against a fixed flat sample with a thermal spray coating. The wear of the tested samples was measured, and the results were computer processed and interpreted. All coating samples showed greater wear resistance than the ShKh15 steel sample. The linear wear of the coatings was 3.7–4.1 times less than that of the steel sample. The plasma-sprayed and detonation-sprayed (TiCrC)Ni coatings had greater wear resistance than the plasma-sprayed coating made of the industrial KKhN-35 material. The detonation-sprayed coating from the (TiCrC)–33 wt.% Ni composite of PKKhT-33 grade exhibited the best wear resistance under dry sliding friction against ShKh15 steel. Its linear wear was approximately 1.3 times less than that of the plasma-sprayed KKhN-35 and PKKhT-33 coatings, while its weight loss was approximately 3–5 times less.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 7-8","pages":"467 - 474"},"PeriodicalIF":0.6,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147865626","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":"Comparative analysis of magnetic properties in nanostructured vs. Bulk FeSi Materials","authors":"M’hamed Ouadah,&nbsp;Abderrahmane Younes,&nbsp;Omar Touhami,&nbsp;Rachid Ibtiouen,&nbsp;Rawya Hendi","doi":"10.1007/s11106-026-00526-3","DOIUrl":"10.1007/s11106-026-00526-3","url":null,"abstract":"<p>This study delves into two distinct aspects of magnetic materials: investigating the impact of grain size on the magnetic circuit of an induction machine by comparing bulk FeSi with a nanostructured Fe–Si alloy with varying silicon concentrations. Initially, the magnetic properties of the induction machine's magnetic circuit are scrutinized, with parameters such as saturation magnetic flux density, coercive field, remanence, and squareness ratio meticulously analyzed. The results reveal a significant influence of grain-size parameters on magnetic behaviour, resulting in a decline in machine efficiency. In the subsequent phase, a nanostructured Fe–Si alloy is synthesized by mechanical alloying with varying silicon concentrations. State-of-the-art techniques, including scanning electron microscopy (SEM) coupled with Energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM), are employed for a comprehensive analysis of morphological, structural, and magnetic properties. Although some studies have suggested the possible formation of the Fe₃Si (suessite) phase during mechanical alloying, its occurrence in the present work remains unproven. According to the equilibrium Fe–Si phase diagram, the Fe₃Si intermetallic compound does not form within the studied range of silicon concentrations. Instead, the observed change in the lattice parameter of the Fe(Si) solid solution after milling suggests a structural transformation within the solid solution itself, likely due to the incorporation of Si atoms into the Fe lattice and the resulting distortion of the bcc structure, rather than the emergence of a new crystalline phase. Increasing silicon concentration results in reduced crystallite sizes, while lattice strain and the parameters increase by up to 3%, remaining constant thereafter. The milled samples exhibit enhanced magnetic properties, with saturation magnetization increasing as silicon concentration decreases.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 5-6","pages":"312 - 322"},"PeriodicalIF":0.6,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147559821","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":"Investigation of Microhardness Behaviors of Ceramic Reinforced Bronze Matrix Composite Materials Using Theoretical Models","authors":"H. Ada,&nbsp;E. Asikuzun Tokeser,&nbsp;E. Turkmen","doi":"10.1007/s11106-026-00527-2","DOIUrl":"10.1007/s11106-026-00527-2","url":null,"abstract":"<p>In this study, Cu–10Sn powders with a size of &lt;44 μm were used as the main matrix material, and SiC (&lt;45 μm) and B₄C (&lt;45 μm) powders of approximately the exact dimensions were used for the reinforcement material. The composite materials were produced by powder metallurgy. In this study, we focused on the analysis of their mechanical properties using a Shimadzu HMV-2 digital microhardness tester and summarized optical microscope and scanning electron microscope (SEM) images of Cu–10Sn/B₄C and Cu–10Sn/SiC composite materials. The images show that the reinforcement particles are homogeneously distributed in the Cu–10Sn matrix. The mechanical properties of the reinforcement materials were determined using the Vickers microhardness test. The decrease in the microhardness values of all samples with increasing applied load indicates their indentation size effect (ISE) behavior. Also, parameters such as the elastic modulus (E), the conditional yield strength of the material when deformed under the indenter (Y), and the critical stress intensity factor (K_Ic), which are as crucial as hardness in mechanical characterizations of materials, were calculated. The load-dependent values of E, Y, and K_Ic decrease with both increases in the B₄C and SiC content and with the applied test load. Different models are presented in the literature to explain ‘indentation size effect/reverse indentation size effect’ (ISE/RISE) behavior. Microhardness comparisons are performed using Meyer's law, the proportional sample resistance (PSR) model, the elastic/plastic deformation (EPD) model, and the Hayes–Kendall approach. According to these analyses, the samples exhibited ISE behavior. The applied load to these samples caused both elastic and plastic deformation. Among these models, the Hays–Kendall approach was more suitable for determining the micromechanical properties and ISE behavior of the samples.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 5-6","pages":"323 - 334"},"PeriodicalIF":0.6,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147559820","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":"Examination of the Real and Imaginary Parts of the Dielectric Permittivity of Aluminum Nitride Composites Before and After the Percolation Threshold","authors":"V. I. Chasnyk,&nbsp;D. V. Chasnyk,&nbsp;O. M. Kaidash","doi":"10.1007/s11106-026-00531-6","DOIUrl":"10.1007/s11106-026-00531-6","url":null,"abstract":"<p>Aluminum nitride composites with high resistivity are used in vacuum microwave devices as bulk microwave absorbers. Their application requires comprehensive characterization of electrophysical parameters over the desired frequency range. This primarily concerns their dielectric characteristics (real ε′ and imaginary ε″ parts of the complex dielectric permittivity and dielectric loss tangent tanδ) and electrical resistivity. For AlN–Mo composites produced by pressureless sintering, the dependences of the real and imaginary parts of complex dielectric permittivity were analyzed for a volume molybdenum content of 14–30%, i.e., both before and after the percolation threshold was exceeded. It was shown that ε′ and ε″ of the composites increased with the content of molybdenum particles both before and after the percolation threshold. Experimental values of the dielectric loss tangent tanδ are presented. They rise from 0.005 to 18 when the content of molybdenum particles increases from 20 to 28%. Starting from 25–30 % Mo, the dependences of the imaginary part ε″ of dielectric permittivity and the dielectric loss tangent tanδ are straight lines on a logarithmic scale. This behavior of tanδ and ε″ makes it possible to determine their values at 30% Mo. In this case, ε′ = 96–106, ε″ = (2.88–3.24) ∙ 10⁴, and tanδ = 300. The calculated imaginary part of complex dielectric permittivity for bulk molybdenum at a frequency of 10 GHz is ε″ = 3.5 · 10⁷, which is more than three orders of magnitude higher than ε″ of the AlN–30% Mo composite. The percolation threshold width for AlN–Mo composites with an average molybdenum particle size of 4–6 μm is about 3% at 25–28% Mo. In this range, the bulk electrical resistivity of the composite decreases from 9 · 10¹³ to 0.6 Ω ∙ cm. After the percolation threshold, over the range of 28–30% Mo, the electrical resistivity further decreases threefold, from 0.6 to 0.2 Ω ∙ cm.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 5-6","pages":"378 - 384"},"PeriodicalIF":0.6,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147559822","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":"Raman Spectra of NiAl/(TiC–Al2O3) Composite Produced by Combustion Synthesis","authors":"Tri Widodo Besar Riyadi,&nbsp;Dessy Ade Pratiwi,&nbsp;Akida Mulyaningtyas","doi":"10.1007/s11106-026-00532-5","DOIUrl":"10.1007/s11106-026-00532-5","url":null,"abstract":"<p>NiAl-based composites reinforced with TiC and Al₂O₃ ceramics have attracted significant interest due to their outstanding high-temperature properties. Combustion synthesis is an effective and efficient processing route for producing the ceramic composite. Since the synthesis reaction occurs at high temperature, precise evaluation of the product is essential. This work analyzes the Raman spectra of the NiAl/(TiC–Al₂O₃) composite structure produced by combustion synthesis. A mixture of Ni/Al and 5 wt.% TiO₂/Al/C was used as the reactant system. The combustion synthesis of the mixtures was initiated by induction heating at 300 A after prior compression to 200 MPa. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) tests were conducted simultaneously to verify the phase analysis observed by the Raman spectroscopy systems. The XRD spectra indicate that the formed product predominantly consists of NiAl matrix, reinforced by TiC and Al₂O₃, suggesting that the synthesis process has fully completed. The SEM images reveal that the ceramic phases, titanium carbide (TiC) and aluminium oxide (Al₂O₃), are unevenly distributed throughout the NiAl matrix. Raman spectra of NiAl, TiC, and Al₂O₃ were analyzed and compared with those of the raw materials. The Raman peaks of the synthesized Al₂O₃ were observed at 1369 and 1400 cm^–1. Whereas, the Raman spectra of the synthesized TiC show two pairs of peak bands, comprising the lower band at 284 and 376 cm^–1, and the higher band at 589 and 668 cm^–1, demonstrating the acoustic and optical bands of the TiC spectra, respectively. Surprisingly, the Raman spectra of NiAl are low in intensity. Thus, the phases analyzed by the Raman shift support those observed by SEM and XRD. This work extends the evaluation of the Raman shifts of TiC, Al₂O₃, and NiAl, including Ni/Al and Ti/C mixtures. Raman analysis provides a comprehensive assessment of the ceramic composite formed by combustion synthesis and confirms the feasibility of using Raman spectroscopy as a reliable research method.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 5-6","pages":"385 - 396"},"PeriodicalIF":0.6,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147559918","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":"Multilayer Coatings as a New Stage in the Development of Modern Highly Effective Thermal Barrier Coatings III. Two-Layer Ln2Zr2O7/YSZ and Other Thermal Barrier Coatings","authors":"S. M. Lakiza,&nbsp;M. I. Hrechaniuk,&nbsp;A. O. Makudera,&nbsp;I. O. Marek,&nbsp;O. K. Ruban,&nbsp;V. P. Red’ko,&nbsp;V. B. Shmybelskii,&nbsp;O. V. Dudnik","doi":"10.1007/s11106-026-00529-0","DOIUrl":"10.1007/s11106-026-00529-0","url":null,"abstract":"<p>The paper provides data on the development of two-layer, multilayer, and functionally graded thermal barrier coatings (TBCs), where zirconates, hafnates, and cerates of rare earth elements, LaMgAl₁₁O₁₉ (LMA), LaTi₂Al₉O₁₉ (LTA), and LaPO₄, phases, Al₂O₃ corundum, and their various combinations serve as the top thermal barrier layer and yttria-stabilized zirconia (YSZ) serves as the bottom layer. The two-layer and multilayer structures exhibit better characteristics than the conventional YSZ coatings and single-layer coatings from the above compounds. This new coating architecture can mitigate the drawbacks of these phases: high sinterability, low fracture toughness, low coefficient of thermal expansion, interaction with the underlying YSZ layer, and low resistance to hot corrosion caused by Ca–Mg–Al silicates (CMAS attack). The most promising topcoat material considered in this paper is La₂Ce₂O₇ lanthanum cerate, as it combines the most suitable properties for the development of new high-temperature two-layer TBCs. The weaknesses of this phase can be reduced through structural modification of the La₂Ce₂O₇ ceramic layer by scientifically grounded selection of methods and parameters for applying both TBC layers and through the control of their thickness. Thus, most disadvantages can be eliminated by the application of two-layer, multilayer, and functionally graded coatings. Since no single material meets all requirements for hightemperature thermal barrier coatings, two-layer ceramic coatings can be an important area for the development of TBCs.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 5-6","pages":"344 - 368"},"PeriodicalIF":0.6,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147559917","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 Influence of Heat Treatment Parameters on the Structure and Microhardness of 316L Steel Produced Using Selective Laser Melting and Conventional Technology","authors":"G. A. Kononenko,&nbsp;P. Ramasamy,&nbsp;Jürgen Eckert,&nbsp;S. V. Adzhamskyi,&nbsp;R. V. Podolskyi,&nbsp;O. A. Safronova,&nbsp;O. A. Shpak","doi":"10.1007/s11106-026-00524-5","DOIUrl":"10.1007/s11106-026-00524-5","url":null,"abstract":"&lt;p&gt;The popularity of 316L steel in the production of parts by selective laser melting is attributed to its unique combination of properties. This paper focuses on a comparative analysis of austenitic 316L steel manufactured by two routes: conventional method in accordance with ASTM A276/A276M-17 Condition A involving rolling and annealing at 1050°C with water cooling and selective laser melting in the starting condition (as-printed). The samples were heat-treated employing well-established and experimental parameters to relieve residual stresses (900°C, water cooling) and to stabilize geometric dimensions (427°C, air cooling). The steel microstructure was examined with an AxioMat 200M optical microscope and a TESCAN electron microscope. Kalling’s reagent was applied for different etching times (10, 30, and 60 sec) to reveal various structural elements and inheritance. Phase diagrams were calculated with the JMatPro software package with thermodynamic databases. The microhardness of structural components was determined with a Zwick/Roell EMCO-TEST microhardness tester under a load of 50 g (with a mapped area of 2.4 mm × 2.4 mm). Simulation of the continuous cooling transformation diagram for 316L steel, taking into account the actual chemical composition and metallographic analysis data, demonstrated that all test samples consisted of austenite after manufacturing and subsequent heat treatment, regardless of the cooling rate and production route. For the samples produced conventionally, the austenite grain size was 40 ± 10 μm in the as-delivered condition, 43.2 ± 8 μm after heating to 427°C, and 56.2 ± 4 μm after heating to 900°C. In the as-delivered condition, the samples exhibited pronounced grain size heterogeneity in the diametral section. The heterogeneity persisted following heating to 427°C but significantly decreased following heating to 900°C. The microhardness of the samples ranged from 208 to 248 HV0.5 in the as-delivered condition, from 250 to 270 HV0.5 after heating to 427°C, and from 180 to 190 HV0.5 after heating to 900°C. Microhardness distribution maps indicated that the microhardness remained heterogeneous after heating to 427°C, although its values increased. The samples heated to 900 °C showed a more uniform distribution of microhardness, but the absolute values decreased. The 316L steel samples produced by selective laser melting preserved the original arc-like structure after heating to 427°C and 900°C. However, after heating to 900°C, the arc-like bands became thinner, and the contrast between the boundaries and the core of the track (formed by a single laser pass over the powder layer) decreased. The microhardness of the samples produced by selective laser melting was 239–251 HV0.5 (in the longitudinal section) and 286–317 HV0.5 (in the transverse section) and changed to 218–248 HV0.5 (in the longitudinal section) and 213–254 HV0.5 (in the transverse section) after heating to 427°C and to 183–208 HV0.5 (in the longitudinal ","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 5-6","pages":"289 - 299"},"PeriodicalIF":0.6,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147560543","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":"Mixing Enthalpies of Melts in the Cu–La–Sc System","authors":"L. O. Romanova,&nbsp;M. I. Ivanov,&nbsp;V. G. Kudin,&nbsp;N. V. Podoprigora,&nbsp;V. S. Sudavtsova","doi":"10.1007/s11106-026-00530-7","DOIUrl":"10.1007/s11106-026-00530-7","url":null,"abstract":"<p>The mixing enthalpies of melts in the La–Sc and Cu–La–Sc systems were determined by high-temperature calorimetry. The mixing enthalpies of La–Sc melts measured in the composition range 0 &lt; <i>x</i>_La &lt; 0.5 at 1830 ± 2 K showed small endothermic effects. Our thermochemical properties and those reported in the literature for La–Sc melts at 0 &lt; <i>x</i>_Sc &lt; 0.5 were used to calculate the mixing enthalpies over the entire composition range. The extrema of the integral mixing enthalpy were ∆<i>H</i>_min = –0.4 ± 0.1 kJ/mol at <i>x</i>_Sc = 0.14 and ∆<i>H</i>_max = 0.8 ± 0.2 kJ/mol at <i>x</i>_Sc = 0.58. The partial mixing enthalpies of lanthanum and copper were determined for melts along four radial sections of the ternary Cu–La–Sc system. The partial mixing enthalpies of lanthanum in the Cu_0.4Sc_0.6 and Cu_0.7Sc_0.3 melts were measured at 1450 ± 1 K for lanthanum concentrations from 0 to <i>x</i>_La = 0.2. The partial mixing enthalpies of copper were measured in the La_0.4Sc_0.6 and La_0.78Sc_0.22 melts at 1450 ± 1 K for copper concentrations 0 &lt; <i>x</i>_Cu &lt; 0.22. The mixing enthalpies of these melts indicate predominantly exothermic effects, attributed to interactions in the binary Cu–Sc system. Reliable thermochemical properties of melts in the bounding binary Cu–La(Sc) and La–Sc subsystems were represented by Redlich–Kister polynomials. On this basis, mixing enthalpies for the ternary melts were calculated employing the analytical Redlich–Kister–Muggianu model. Comparison of the experimental and calculated mixing enthalpies of these melts indicated that our data and those found with the Redlich–Kister–Muggianu model agreed without ternary contribution within the experimental error. The extremum of the integral molar mixing enthalpy in the ternary Cu–La–Sc system was –24 ± 1 kJ/mol, located near the equiatomic composition of the Cu–Sc melts. Thus, the principal contribution to the interaction energy between unlike atoms in the studied melts arises from this bounding subsystem. The research results were analyzed within the modern electronic theory of metals.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 5-6","pages":"369 - 377"},"PeriodicalIF":0.6,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147560596","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}