Journal of Superhard Materials最新文献

{"title":"Functionally Gradient ZrC–Al2O3 Based Ceramic Synthesized from an Exothermic 70ZrO2–24Al–6C Mixture under Hot Pressing in Contact with Colloid Graphite","authors":"M. M. Prokopiv,&nbsp;O. V. Kharchenko,&nbsp;M. Ye. Chernova","doi":"10.3103/S1063457625060048","DOIUrl":"10.3103/S1063457625060048","url":null,"abstract":"<p>The structure and properties of functionally gradient ceramic synthesized from an exothermic 70ZrO₂–24Al–6С (wt %) mixture under hot pressing in contact with colloid graphite are described. It has been established that two layers with a gradient structure are formed on the surface of the specimen with a structure that includes two complexly alloyed carbide ZrC and oxide Al₂O₃ based phases with a volumetric ratio of 55 : 45 and a size of 2–15 µm % and disperse (1–3-µm) 10Zr₂Al and 5ZrO_2(М) (wt %) inclusions. The layer with a gradient microstructure formed at the interface with the basic microstructure (BMS) with a thickness of 1.0–1.2 mm contains both the complex ZrС–Al₂O₃ based phases and finer (0.5–2-µm) spherical inclusions with a volumetric ratio of 45 : 55 without disperse Zr₂Al and ZrO_2(М) inclusions. The microhardness HV15 of the specimen with gradient and basic microstructures is 19.6 and 16.6 GPa, and the fracture toughness is <i>K</i>_Ic = 5.5 and 6.2 MPa m^0.5, respectively. The outer dark layer, which has a thickness up to 0.5 mm and contains up to 50 wt % of carbon and disperse (1–2-µm) inclusions on the basis of carbide ZrC and oxide Al₂O₃, has microhardness up to 4 GPa. Cutting inserts with a gradient microstructure have an advantage over inserts with the basic microstructure in the dry finish turning of steel KhVG (58 HRC) that grows with an increase in the cutting speed from 120 to 220 m/min. The reason for the formation of the functionally gradient fine-grained two-layer structure with a change in chemical composition with improved cutting properties is a temperature gradient on the specimen surface, a high activity of alumocarbothermal chemical interaction in the initial mixture, and partial migration under pressure during the hot pressing of an Al–Zr₂Al melt from the basic structure into the contacting layer from the colloid graphite and their chemical interaction in the oxygen atmosphere.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 6","pages":"446 - 456"},"PeriodicalIF":1.2,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145808616","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":"Novel Ultrahard Monoclinic Carbon Allotropes from Crystal Structure Engineering and First Principles","authors":"S. F. Matar,&nbsp;V. L. Solozhenko","doi":"10.3103/S1063457625060024","DOIUrl":"10.3103/S1063457625060024","url":null,"abstract":"<p>Two novel monoclinic (space group <i>C</i>2/<i>c</i>) carbon allotropes, <i>m</i>-C₈, with ths and dia topologies, were proposed through crystal structure engineering. The ths allotrope is built by three-dimensional tiling of trigonal carbon units, which is different from tiling of <i>C4</i> tetrahedra in the case of dia <i>m</i>‑C₈. Structural studies were supported by density functional theory (DFT)-based calculations of ground state structures and energy-derived properties. Extensive investigations of cohesive energies, energy-volume equations of state, mechanical (elastic constants and moduli, hardness) and dynamical (e.g., phonons) properties revealed the new allotropes to be cohesive and stable both mechanically and dynamically. Although they are metastable compared to diamond, their formation is possible under non-equilibrium conditions as a result of alternative metastable behavior.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 6","pages":"430 - 438"},"PeriodicalIF":1.2,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145808672","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":"Studying the Microstructural Properties of Tungsten Carbide–Cobalt Composite Materials by Advanced Image Processing Methods","authors":"O. A. Pashchenko,&nbsp;Ye. A. Koroviaka,&nbsp;V. L. Khomenko,&nbsp;O. F. Kamyshatskyi,&nbsp;S. O. Shypunov","doi":"10.3103/S106345762506005X","DOIUrl":"10.3103/S106345762506005X","url":null,"abstract":"<p>The effect of the microstructure of tungsten carbide–cobalt (WC–Co) composites on their mechanical properties, such as hardness and wear resistance critical for cutting tools and drilling equipment was considered. An innovative method of microstructural analysis based on image processing was proposed as a faster and more efficient alternative to traditional methods like scanning electron microscopy (SEM) and X-ray diffraction. The porosity and tungsten carbide particle and cobalt binder phase distribution were investigated by image preprocessing, phase segmentation, and quantitative SEM analysis. The results demonstrate a high precision of the method in estimating the key characteristics at an essential decrease in time and expenditures and make it possible to improve the quality and durability of WC–Co materials in industrial applications.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 6","pages":"457 - 466"},"PeriodicalIF":1.2,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145808708","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":"Optimizing the Cooling Process of Pressure Punches in a Six-Punch Press for Single-Crystal Diamond Growth","authors":"A. V. Burchenya,&nbsp;V. V. Lysakovsky,&nbsp;T. V. Kovalenko,&nbsp;S. O. Ivakhnenko","doi":"10.3103/S1063457625060036","DOIUrl":"10.3103/S1063457625060036","url":null,"abstract":"<p>This study explores experimental approaches to cooling heat-removal liquids based on distilled water for six-punch press systems operating under a total loading force of 6 × 48.5 MN during the growth of structurally perfect diamond single crystals by the temperature gradient method. A cooling system for hard-alloy punches was designed and fabricated with programmable control of flow rate in each of the six independent circuits, based on punch temperature feedback. Experiments showed that varying the coolant flow rate between 4 and 10 L min^–1 at temperatures of 18 and 24°C enables adjustment of the growth-cell control-point temperatures within 18–35°C, respectively. Regulating the punch cooling conditions according to a predefined algorithm during the diamond growth process maintains the optimal temperature distribution within the growth cell, enabling the formation of structurally perfect, flat-faced diamond single crystals weighing up to 20 carats or more.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 6","pages":"439 - 445"},"PeriodicalIF":1.2,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145808655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of Hafnium as a Sintering Activator of BL Group Composites in the cBN–HfC System","authors":"D. A. Stratiichuk,&nbsp;Ya. M. Romanenko,&nbsp;S. P. Starik,&nbsp;V. Z. Turkevich","doi":"10.3103/S1063457625050119","DOIUrl":"10.3103/S1063457625050119","url":null,"abstract":"<p>This study examines selected aspects of the formation of nonporous ceramic-matrix composites of the BL group in the cBN–HfC system, where hafnium micropowder serves as a sintering activator. The results demonstrate that, during HPHT experiments at 2300°C, the system undergoes reactive sintering characterized by the disappearance of the metallic phase and the formation of fine-grained HfB₂ through two mechanisms, with a volume fraction of up to 8%.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 5","pages":"418 - 420"},"PeriodicalIF":1.2,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145327662","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 Composition of SiC–Al2O3 Composites on Hardness and Fracture Toughness","authors":"A. H. Dovhal,&nbsp;L. B. Pryimak,&nbsp;O. M. Biliakovych","doi":"10.3103/S1063457625050028","DOIUrl":"10.3103/S1063457625050028","url":null,"abstract":"<p>The effect of the composition of a SiC–Al₂O₃ composite on the hardness and fracture toughness calculated by an indirect method from the total length of cracks in the corners of rhombic imprints on a Vickers hardness meter has been studied. The dependences of the hardness and fracture toughness of these composites on the content of composite components have been established.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 5","pages":"358 - 369"},"PeriodicalIF":1.2,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145327667","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":"Mechanism of Polishing Aluminum Optical Components","authors":"Yu. D. Filatov,&nbsp;T. O. Prikhna,&nbsp;A. Y. Boyarintsev,&nbsp;V. I. Sidorko,&nbsp;S. V. Kovalev","doi":"10.3103/S106345762505003X","DOIUrl":"10.3103/S106345762505003X","url":null,"abstract":"<p>As a result of studying the regularities inherent in the process of treated material removal and the formation of a polished surface nanoprofile during the polishing of aluminum optical components with a disperse system of copper metaborate micro- and nanopowders, it has been established that the formation and elimination of sludge nanoparticles occurs due to energy transfer from the polishing powder particles to the treated surface by the QD-FRET mechanism of Förster resonance energy transfer mediated by Al₂O₃ quantum dots (QDs) formed on the surface of aluminum. It has been shown that the rate of treated material removal in the process of aluminum polishing with a disperse copper metaborate–kerosene based system depends on the quality factor of the microresonator formed by the surfaces of a treated material and a polishing powder particle and the lifetime of the excited state of quantum dots on the treated surface according to the general regularities of the polishing process. It has been established that the results of theoretical calculation for the treated material removal rate are in good agreement with the experimental data of measuring the aluminum polishing rate at an error of 1–5%. It has been demonstrated that, in terms of polishing rate and polished surface roughness for aluminum optical components, it is advisable to use a disperse system of copper metaborate micro- and nanopowders.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 5","pages":"388 - 395"},"PeriodicalIF":1.2,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145327597","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":"Thermodynamics of the Formation of Bi-Mesostructures in Composite Materials","authors":"A. F. Lisovsky,&nbsp;O. O. Matviichuk,&nbsp;S. A. Davydenko","doi":"10.3103/S1063457625050053","DOIUrl":"10.3103/S1063457625050053","url":null,"abstract":"<p>We conducted a thermodynamic analysis of the structural formation of class I and II bi-mesocomposites in cemented carbides composed of mesoelements and a matrix. We derived expressions describing the change in Helmholtz free energy during solid-phase and liquid-phase sintering of these bi-mesocomposites. The results show that forming stable bi-mesostructures in cemented carbides requires solid-phase sintering for class I mesostructures, whereas producing class II bi-mesocomposites by liquid-phase sintering requires effective wetting of the mesoelements. Using this approach, we obtained a WC–20 wt % Co–2 wt % C bi-mesostructure through liquid-phase sintering.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 5","pages":"337 - 343"},"PeriodicalIF":1.2,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145327656","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 and Mechanical Wear Behavior of MoSi2–Al2O3 Composite","authors":"Xue Mao-chao","doi":"10.3103/S1063457625050065","DOIUrl":"10.3103/S1063457625050065","url":null,"abstract":"<p>Using MoO₃, Mo, Al and Si powders as raw materials, MoSi₂ and MoSi₂–Al₂O₃ composite were prepared by mechanochemical reduction and hot press sintering techniques. The microstructure and dry sliding wear behavior of the samples were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and a ball-on-disk reciprocating tribometer. The results showed that MoSi₂–Al₂O₃ composite has a fine microstructure, high hardness (13.4 GPa) and fracture toughness (7.2 MPa m^0.5) compared to the pure MoSi₂ material. The wear test results indicated that MoSi₂ and MoSi₂–Al₂O₃ composite exhibited good tribological properties against sliding GCr15 steel balls under different loads. The friction coefficient and wear rates of the samples decreased as the applied load increased. Compared to pure MoSi₂, MoSi₂–Al₂O₃ composite exhibited better wear resistance due to its high hardness, fracture toughness and good surface lubrication characteristics. The dominant wear mechanisms of the composite were adhesion, tribo-oxidation, plastic deformation and spalling.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 5","pages":"370 - 379"},"PeriodicalIF":1.2,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145327659","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":"A Review on Ternary Compounds of High Boron Transition Metals as Hardness Materials","authors":"G. Shwetha,&nbsp; Thirupathi Gadipelly","doi":"10.3103/S1063457625050107","DOIUrl":"10.3103/S1063457625050107","url":null,"abstract":"<p>The high-pressure studies are less explored on high boron-based transition metals (HBTM) ternary compositions. Despite applications, most of the literature on boron-based compounds is limited to the studies of mono and di boron-based (AB and AB₂) compounds. This review reports the detailed theoretical and experimental studies of HBTM ternary compounds to direct this research area. Most of these compounds are employed as hardness materials, magnetic materials, superconductors, 2D materials, catalysts etc. The discussion is extended to various recent HBTM ternary compounds followed by significant advancements and challenges as a promising domain.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 5","pages":"380 - 387"},"PeriodicalIF":1.2,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145327661","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}