Powder Metallurgy and Metal Ceramics最新文献

{"title":"Refining the Understanding of the Thermionic Emission Mechanism in Impregnated WBa and ScBa Cathodes Based on G.V. Samsonov’s Configurational Model II. Refined Polarization WBa-IC and ScBa-IC Thermionic Emission Model from the Standpoint of G.V. Samsonov’s Configurational Model","authors":"I. O. Podchernyaeva,&nbsp;O. I. Hetman","doi":"10.1007/s11106-025-00511-2","DOIUrl":"10.1007/s11106-025-00511-2","url":null,"abstract":"<p>The first part presented a comprehensive review of experimental studies on various types of impregnated WBa and ScBa cathodes (WBa-ICs and ScBa-ICs), used to develop thermionic emission models intended to clarify the mechanisms whereby CaO and Sc₂O₃ oxides and platinum-group metals influence cathode emission. The second part analyzes the proposed polarization WBa-IC and ScBa-IC thermionic emission model for the first time from the standpoint of G.V. Samsonov’s configurational model. The new polarization model differs from existing ones in that it incorporates donor–acceptor interactions between valence orbitals of adatoms within the emission–adsorption layer and between these adatoms and adsorbent atoms, initiated by changes in the energy stability of valence orbital configurations. According to the proposed polarization WBa-IC and ScBa-IC thermionic emission model, the electron work function is determined by the potential barriers of polarized dipole complexes of two types. These complexes result from donor–acceptor interactions between adatoms themselves and between adatoms and adsorbent atoms, Ba(Ca, Sc)⁺–O^––A⁺, and from those between adsorbed oxide molecules and adsorbent atoms, Ba⁺O^– (Ca⁺O^–)–A⁺, (Ba⁺O^––Sc^–₂O^–₃–Al⁺₂O^–₃)–A⁺, and (Ba⁺O^––Sc^–₂O^–₃–W⁺O^–₃)–A⁺. In both types, the bond between the adsorbate and the adsorbent is mediated by oxygen, acting as the electron acceptor. The characteristics of these interactions are defined by the energy stability of valence orbital configurations, d⁰, d⁵, and d¹⁰ for d-metals and s², sp³, and s²p⁶ for sp-elements, and their donor–acceptor capability. The new polarization WBa–IC and ScBa–IC thermionic emission model explains the effects of doping with CaO and Sc₂O₃ oxides and with platinum-group d-transition metals on cathode emission. Although the results are only qualitative, they are mutually consistent and correlate with emission characteristics. The simplicity of interpretation makes G.V. Samsonov’s configurational model suitable for examining charge-transfer interactions in adsorbate–adsorbent systems.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 1-2","pages":"116 - 128"},"PeriodicalIF":0.6,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145646166","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-Induced Deposition of a Functional Titanium Coating on Oxide Ceramics for Subsequent Brazing with Metallic Filler Alloys","authors":"V. S. Zhuravlev,&nbsp;V. P. Krasovskyy","doi":"10.1007/s11106-025-00509-w","DOIUrl":"10.1007/s11106-025-00509-w","url":null,"abstract":"<p>The brazing of dissimilar materials, despite significant progress in the field, still requires fundamental physical, chemical, and technological research and necessitates improvements to existing brazing processes and filler alloys and the development of new multicomponent alloys, metallization coatings, and methods for their application. An option for improving the wetting of nonmetallic materials by filler melts that do not wet ceramic surfaces includes their metallization with adhesion promoters deposited by friction-induced rubbing. Three new types of titanium tools for rubbing nonmetallic surfaces, using a porous sponge-like structure or foil of VT1-0 titanium with a thickness of 0.07–0.10 mm, were proposed and fabricated. This approach is intended to reduce both the force separating the metallizing particles from the tool and the rigidity of the contact interaction. A device was developed for argon purging of the ceramic surface during air metallization. The purging operation in the metallization process significantly improves brazing by lowering the wetting onset temperature and reducing the amount of titanium oxides in the brazed joint. Samples of high-alumina A995 and VK94-1 ceramics were metallized by the proposed method. The wetting of these ceramics with PSr72 filler alloy (copper–silver eutectic) was studied, brazed joints were produced, and the microstructure of the metal–oxide interface was analyzed. Microstructural analysis revealed that the PSr72 melt permeated the titanium coating, became saturated with titanium, and wetted the ceramic surface. This indicates that this metallization method does not require a dense coating and accelerates the saturation of the melt with titanium. The surface roughness of nonmetals was found to influence the composition and microstructure of the coating deposited in air. As surface roughness decreased, both the coating density and oxidation increased. The primary role of friction-induced metallization is to deliver titanium into the filler melt. The advantages of rubbing nonmetallic materials with a porous titanium sponge or foil, compared to tools made from compact titanium, were indicated. The best results were showed by the porous titanium tool.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 1-2","pages":"102 - 109"},"PeriodicalIF":0.6,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145646165","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 Nano-BN on the Tribological Properties of Aramid Fiber Composites","authors":"Dong Liang,&nbsp;Sang Xiong,&nbsp;Jin Zhang,&nbsp;Ningning Lu,&nbsp;Xingcheng Jiang","doi":"10.1007/s11106-025-00504-1","DOIUrl":"10.1007/s11106-025-00504-1","url":null,"abstract":"<p>Aramid fibers, with their excellent mechanical properties and thermal stability, face limitations in tribological applications due to surface inertness. In this study, aramid fibers were modified with the silane coupling agent KH550. Subsequently, composites containing different amounts of nano-BN (ranging from 0 to 2.5%) were prepared using an epoxy resin matrix and an aramid fiber via the vacuum infusion process. FTIR confirmed successful fiber modification, showing new peaks at 2925, 2852, and 3310 cm^–1 from methylene, methoxy, and amino groups, respectively. The incorporation of nano-BN was confirmed by SEM-EDS through the detection of B and N elements. Tribological tests on an MFT-3000 tester under 100 N load, 10 Hz frequency, 1 mm wear distance, and 15 min duration revealed optimal performance at 0.5 wt.% nano-BN. SEM results showed the COF of ~0.4 and wear rate of 6.2∙10^–10 m³∙(N∙m)^–1, attributed to a stable transfer film reducing direct contact. However, as the BN content increased, the agglomeration of nano-BN became more severe. This agglomeration led to an elevation in both the wear rate and the COF. Besides, the load and friction speed had a significant impact on the friction and wear performance of the composites, with higher speeds increasing the rate of wear and the volatility of the coefficient. The primary wear mechanism was identified as adhesive wear. Nano-BN played a crucial role in facilitating the formation of a transfer film by enhancing the wear resistance of the composites and effectively decreasing the COF.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 1-2","pages":"36 - 51"},"PeriodicalIF":0.6,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145646167","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 Corrosion Behavior of (TiB2–SiC)–(Ni–20% Cr) Composite Coatings in Natural Electrolytes","authors":"V. L. Syrovatka,&nbsp;V. M. Talash,&nbsp;A. V. Minitskyi,&nbsp;A. A. Bondarenko,&nbsp;K. M. Galtsov,&nbsp;O. Ye. Terentiev,&nbsp;T. M. Chevychelova,&nbsp;V. T. Varchenko,&nbsp;I. S. Martseniuk","doi":"10.1007/s11106-025-00510-3","DOIUrl":"10.1007/s11106-025-00510-3","url":null,"abstract":"<p>The corrosion resistance of compact materials and composite coatings in the (TiB₂–SiC)–(Ni–20% Cr) system was studied in a 3% NaCl solution simulating seawater using potentiodynamic polarization curves. Both the compact materials and the composite coatings in the (TiB₂–SiC)–(Ni–20% Cr) system exhibited high corrosion resistance in aggressive environments. It was established that the corrosion resistance of the coatings in a 3% NaCl solution could be significantly increased by adjusting its composition: specifically, by reducing the nickel content and increasing the TiB₂–SiC content. The starting materials for spraying were (TiB₂–SiC)–x(Ni–20% Cr) powders with x = = 20, 30, and 40 wt.%. Coatings were deposited onto Steel 3 substrates by detonation and plasma spraying. For detonation spraying (Dnipro-5M installation), composite powders with a particle size fraction of −63+40 μm were used. Plasma spraying (UPU-3D installation) employed powders with a size fraction of −120+63 μm. The spraying process proceeded with a mixture of argon and hydrogen as plasma-generating gases in an open atmosphere. The results demonstrate the feasibility of using detonation- and plasma-sprayed coatings in the (TiB₂–SiC)–(Ni–20% Cr) system with enhanced properties in mechanical engineering and aerospace applications.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 1-2","pages":"110 - 115"},"PeriodicalIF":0.6,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145646184","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":"Optimization of the Basalt Grinding Process in a Planetary Ball Mill","authors":"Singgih Prabowo,&nbsp;Herma Yudhi Irwanto,&nbsp;Sukmaji I. Cahyono,&nbsp;Adyasha Swain Mohapatra,&nbsp;Rohit Kumar,&nbsp;Diah Susanti,&nbsp;Fathan Bahfie","doi":"10.1007/s11106-025-00502-3","DOIUrl":"10.1007/s11106-025-00502-3","url":null,"abstract":"<p>Basalt stone is widely used as a filler in composite materials. The heat-resistant and hard nature of basalt stone, which is formed from volcanoes, makes it essential for the thermal and mechanical properties of composite materials to be improved. The improvement of these properties is affected by the size of the material used. The smaller the filler particles, the greater the contact between the matrix and the filler particles in the composite material. This automatically increases the bond between them and improves the material's properties. Basalt, originally large in size, is processed into nano-sized to maximize its function. To reduce the size of basalt to the nanoscale, a planetary ball mill was used, in which stainless steel and zirconium balls rotate at a certain speed for varying periods of time. The effect of changes in rotation speed, grinding time, and the type of balls used in the planetary ball mill on the dispersibility and morphology of the ground material was studied. Both the rotating speed and milling time impact the size obtained. Significant size reductions occur when the rotation is faster and the milling time is longer. However, the change becomes less significant after a specific period. The smallest size obtained is 199.9 nm, which is 14% of the initial size before milling, which was 1421.9 nm. This smallest size is achieved through three stages of the process, using different balls at each stage.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"64 1-2","pages":"18 - 26"},"PeriodicalIF":0.6,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145646185","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":"Preparation of Boehmite by the Hydrothermal Method and Analysis of its Dehydration Kinetics","authors":"Yanhua Sun,&nbsp;Zhongxiang Shi,&nbsp;Jing Wang,&nbsp;Kenan Xu","doi":"10.1007/s11106-025-00497-x","DOIUrl":"10.1007/s11106-025-00497-x","url":null,"abstract":"<p>Boehmite (AlOOH), due to its porous structure, excellent adsorption properties and high thermal stability, is widely used in various areas, including petrochemistry, biology and medicine (catalysts, flame retardants, functional ceramics, etc.). We propose replacing traditional Al salts (or Al alkoxides) with industrial-grade aluminium hydroxide Al(OH)₃ as the precursor and using a hydrothermal method to synthesise phase-pure boehmite powder. The phase transition from gibbsite to boehmite can be achieved by adjusting the hydrothermal temperature using industrial-grade aluminum hydroxide (Al(OH)₃) as the starting material. Based on this, the study investigated the influence of hydrothermal reaction temperature on the crystal structure and microscopic morphology of boehmite. The samples were characterized using a variety of analytical methods, including XRD, SEM, TEM, HRTEM, particle size distribution, and TG–DSC, to comprehensively analyze the phase, microscopic morphology, and phase transition process. Results demonstrate that pure-phase boehmite powder with a square plate-like morphology can be obtained at hydrothermal temperatures above 180°C. The square plates exhibit smooth surfaces, clear boundaries, and an average particle size of approximately 0.88 μm. Dehydration kinetics analysis using the Popescu method confirms that the synthesized boehmite has a thermal decomposition temperature above 700K and a dehydration weight loss of 17%. The dehydration process follows a model mechanism function of f(α) = 2(1 – α)^1/2, indicating a two-dimensional phase boundary reaction of shrinking cylindrical bodies. The average activation energy (E_a) for the dehydration process is determined to be 211.40 kJ/mol, the average pre-exponential factor (A) is 5.05 · 10¹³ min^–1, and the average correlation coefficient (R²) is 0.9939.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 11-12","pages":"712 - 721"},"PeriodicalIF":0.6,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144929430","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) IV. Biological Methods (Green Synthesis)","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/s11106-025-00495-z","DOIUrl":"10.1007/s11106-025-00495-z","url":null,"abstract":"<p>Biological methods (green synthesis) involving natural sources (bacteria, fungi, algae, plants, etc.) were developed in the 21st century in South and East Asia, South America, and Middle East countries. The mechanism of ZrO₂ nanoparticle formation using microbial systems (bacteria and fungi) includes biosorption and bioreduction. Rounded and rod-shaped primary particles, comprising a mixture of m-ZrO₂ and t-ZrO₂ phases, were synthesized. These powders exhibit effective antimicrobial and antibiofilm activity and are promising for the delivery of pH-sensitive drugs and the development of biosensors. The use of various plant extracts in thermal decomposition, coprecipitation, sol–gel processes, solution combustion, and hydrothermal synthesis was explored. The growth of ZrO₂ nanoparticles during green synthesis proceeds through three stages: activation, growth, and termination. The resulting ZrO₂ powders hold promise for applications in novel antimicrobial agents, anticancer drugs, photocatalysts for wastewater treatment, fillers in polymer nanocomposites, and nanoadditives to enhance the efficiency of diesel engines. Composite powders such as ZrO₂/RGO with improved anticancer properties, ZrO₂/PdO and ZrO₂ : Sm³⁺ (11 mol.%) for photocatalysts, and ZrO₂ : Mg (0.1–5 mol.%) for nanophosphors in display devices were developed. The choice of the synthesis route for the starting powders is based on the intended application of the final material. The synergistic effect of physicochemical and biological approaches in green synthesis expands the potential for microstructural design of functional ZrO₂-based materials for diverse applications.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 11-12","pages":"687 - 701"},"PeriodicalIF":0.6,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144929428","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":"Refining the Understanding of the Thermionic Emission Mechanism in Impregnated WBa and ScBa Cathodes Based on G.V. Samsonov’s Configurational Model I. Analysis of the Chemical Composition and Structure of the Emission–Adsorption Layer in WBa and ScBa Cathodes","authors":"I. O. Podchernyaeva,&nbsp;O. I. Hetman","doi":"10.1007/s11106-025-00498-w","DOIUrl":"10.1007/s11106-025-00498-w","url":null,"abstract":"&lt;p&gt;The first part presents an analysis of existing experimental studies on various types of impregnated WBa and ScBa cathodes (WBa-ICs and ScBa-ICs), underlying the development of polarization and semiconductor thermionic emission models intended to clarify the mechanisms whereby CaO and Sc&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; oxides and platinum-group metals influence cathode emission. The analysis of existing polarization and semiconductor WBa-IC and ScBa-IC thermionic emission models shows that there is no universally accepted thermionic emission model. An interpretation of the chemical composition and structure of the emission–adsorption layer (EAL) in WBa-ICs is proposed. This interpretation serves as the basis for evaluating interatomic interactions within the EAL, relying on G.V. Samsonov’s configurational model of the electronic structure in solids. The EAL on the tungsten adsorbent in WBa-ICs consists of two structural–phase components: a two-dimensional Ba–O monolayer adsorbed on the tungsten surface and three-dimensional BaO–CaO oxides located within the pores and along their perimeters in the tungsten skeleton. The chemical composition and structure of the EAL in ScBa-ICs depend on the production technology. There is currently no consensus regarding the role of scandium and scandium-containing compounds in the characteristics of ScBa-ICs, which prevents the development of a unified thermionic emission model for ScBa-ICs. The polarization WBa-IC and ScBa-IC thermionic emission model proposed in the second part is for the first time analyzed from the standpoint of G.V. Samsonov’s configurational model. The new polarization model differs from existing ones in that it incorporates donor–acceptor interactions among valence orbitals of the adatoms within the EAL and between these adatoms and atoms of the adsorbent, initiated by changes in the energy stability of valence orbital configurations. In the proposed polarization WBa-IC and ScBa-IC thermionic emission model, the electron work function is determined by the potential barriers of polarized dipole complexes of two types. The first type is formed through donor–acceptor interactions between adatoms themselves and between adatoms and adsorbent atoms Ba (Ca, Sc)&lt;sup&gt;+&lt;/sup&gt;–O&lt;sup&gt;–&lt;/sup&gt;–A&lt;sup&gt;+&lt;/sup&gt;. The second type involves adsorbed oxide molecules interacting with adsorbent atoms Ba&lt;sup&gt;+&lt;/sup&gt;O&lt;sup&gt;–&lt;/sup&gt; (Ca&lt;sup&gt;+&lt;/sup&gt;O&lt;sup&gt;–&lt;/sup&gt;)–A&lt;sup&gt;+&lt;/sup&gt;, (&lt;span&gt;({text{Ba}}^{+}{text{O}}^{-}-{text{Sc}}_{2}^{+}{text{O}}_{3}^{-}-{text{Al}}_{2}^{+}{text{O}}_{3}^{-})&lt;/span&gt;)–A&lt;sup&gt;+&lt;/sup&gt;, and (&lt;span&gt;({text{Ba}}^{+}{text{O}}^{-}-{text{Sc}}_{2}^{+}{text{O}}_{3}^{-}-{text{W}}^{+}{text{O}}_{3}^{-})&lt;/span&gt;)–A&lt;sup&gt;+&lt;/sup&gt;. In all these complexes, the bond between the adsorbate and the adsorbent is mediated by oxygen, acting as an electron acceptor. The characteristics of the donor–acceptor interaction are defined by the energy stability of valence orbital configurations, d&lt;sup&gt;0&lt;/sup&gt;, d&lt;sup&gt;5&lt;/sup&gt;, and d&lt;sup&gt;","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 11-12","pages":"722 - 734"},"PeriodicalIF":0.6,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144929329","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 the Size and Mechanical Strength of Natural Diamond Grains in the Matrix of Diamond Tube Drills on Their Performances in the Drilling of Selected Nonmetallic Materials","authors":"V. P. Umansky,&nbsp;V. P. Krasovskyy,&nbsp;O. O. Bashchenko","doi":"10.1007/s11106-025-00499-9","DOIUrl":"10.1007/s11106-025-00499-9","url":null,"abstract":"<p>Six diamond tube drills were fabricated by vacuum impregnation using cutting grains of natural diamonds of grade A1 with grain sizes of 250/200, 315/250, 500/400, 800/600, 1000/800, and 1200/1000 μm. For comparative analysis, three drills were produced with synthetic diamonds of grades AS32 500/400, AS400 315/250, and AS400 500/400 (DSTU 3292–95). To ensure reliable fixation in the tool body, diamond grains coated with molybdenum and copper were embedded in a Cu–15 wt.% Sn matrix with added fillers (5 wt.% ultrafine diamond powder of grade ASM 1/0 and molybdenum). The compressive strength of the diamond grains was evaluated. The paper presents results from comparative laboratory tests of the diamond drills in marble, granite, and silicon carbide-based abrasive stone. Performance characteristics—drilling speed and drill wear—were studied as functions of the natural diamond grade used. The drilling speed depended on the size of the diamond grains. The lowest drilling speeds (3.52, 6.83, and 23.1 mm/min for granite, marble, and abrasive stone) were observed in drills equipped with small (A1 250/200 μm) and weak (50 N) diamond grains. When larger (A1 1200/1000 μm) and stronger (350 N) diamond grains were used, the drilling speed increased significantly (by approximately 4, 3.2, and 3.8 times) to 14.07, 22.1, and 87.99 mm/min for granite, marble, and abrasive stone, respectively. The lowest drilling speed observed in granite with all tested drills was due to its high hardness, being approximately twice that of marble. However, despite even greater hardness of silicon carbide, forming the base of the abrasive stone, the drilling speed remained high. When marble was drilled with tools containing the smallest diamond grains (A1 250/200 μm), their wear amounted to 0.0139 g. For harder materials (granite and abrasive stone), tool wear increased significantly (by factors of 41 and 48), reaching 0.5701 and 0.6665 g. With increasing grain size and compressive strength of the natural diamond grains, drill wear decreased, by factors of approximately 8, 317, and 14 for marble, granite, and abrasive stone. The greatest reduction in wear was recorded for granite. As a result, drills equipped with large and strong diamond grains (A1 1000/800 and A1 1200/1000) exhibited similarly minimal wear in the drilling of marble and granite: 0.0036 and 0.0018 g for granite and 0.0035 and 0.0017 g for marble.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 11-12","pages":"735 - 741"},"PeriodicalIF":0.6,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144929368","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":"Acoustic Study of Elasticity and Damping Properties of Polypropylene Composites Reinforced with Titanium Nitride Particles for 3D Printing","authors":"O. V. Vdovychenko,&nbsp;O. B. Zgalat-Lozynskyy,&nbsp;A. M. Kolesnykov,&nbsp;O. O. Matviichuk","doi":"10.1007/s11106-025-00496-y","DOIUrl":"10.1007/s11106-025-00496-y","url":null,"abstract":"<p>Composite materials reinforced with titanium nitride particles, which serve as the basis for manufacturing 3D-printed components that are promising for use in extreme environments, such as cutting tools, wear-resistant and protective coatings, biomedical products, and electrochemical energy capacitors, were studied. Linear and nonlinear acoustic methods were employed to evaluate the elastic and damping properties of polypropylene-based composites reinforced with up to 46 vol.% titanium nitride particles. When the volume content of titanium nitride particles raised from 20% to 46%, Young’s modulus of the composites was found to increase from 4.91 to 9.77 GPa and their shear modulus from 1.85 to 3.55 GPa. The dependence of both elastic moduli on the ceramic volume content over the studied range can be described with satisfactory accuracy by the Halpin–Tsai equation, using an empirical reinforcement particle shape factor of 4.2, which closely matches the experimentally determined value. The damping capacity of the studied composites ranged from 0.06 to 0.12 and was slightly lower in the composite with the higher titanium nitride content. The damping behavior of the composites as a function of the maximum cyclic strain amplitude exhibited a minimum at stress levels around 2.5 MPa. At the same stress levels, a discontinuity in the amplitude dependence of the relative resonance frequency shift was observed. The authors attribute both phenomena to structural transformations within the composite that occur during cyclic deformation under the specified amplitudes and oscillation frequencies. The results demonstrate the potential of acoustic nondestructive methods to monitor the quality of filaments for 3D printing and finished composite products.</p>","PeriodicalId":742,"journal":{"name":"Powder Metallurgy and Metal Ceramics","volume":"63 11-12","pages":"702 - 711"},"PeriodicalIF":0.6,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144929429","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}