Journal of Superhard Materials最新文献

{"title":"Novel Highly Symmetrical Superhard C48 and C32 Allotropes with Original Topologies: Crystal Engineering and DFT Investigations","authors":"Samir F. Matar","doi":"10.3103/S1063457626010156","DOIUrl":"10.3103/S1063457626010156","url":null,"abstract":"<p>Novel high symmetrical body centered carbon allotropes: cubic C₄₈ and tetragonal C₃₂ are proposed with respective original “<b>ana</b>” and “<b>ukc</b>” topologies. Devised from crystal structure engineering, their ground state structures and energy derived physical properties were accurately derived from quantum mechanics calculations within the density functional theory DFT. Both allotropes made of distorted tetrahedral C4 arrangements were found dense with ρ &gt; 3 g/cm³ that remains lower than diamond density: ρ = 3.55 g/cm³. With cohesive albeit metastable ground state structures versus diamond, both allotropes show stability from the mechanical (elastic properties), dynamic (phonons band structures), as well as thermodynamic properties that show relationship with diamond’s experimental <i>C</i>_V = <i>f</i>(<i>T</i>) discrete results. Vickers hardness magnitudes <i>H</i>_V(C₄₈) = 47 GPa and <i>H</i>_V(C₃₂) = 59 GPa indicate super-hard materials. The electronic band structures range from large direct band gap ∼5 eV for C₄₈ to indirect band gap ~2.5 eV of semi-conducting-like C₃₂. Such findings of original allotropes with targeted physical properties are bound to enrich the field of research on carbon allotropes especially highly symmetrical ones.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"48 1","pages":"27 - 34"},"PeriodicalIF":1.2,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147352678","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 SiC Content and Physicochemical Properties on the Heat Resistance and Mechanical Characteristics of Ultra-High-Temperature HfB2–SiC Composites Synthesized by Hot Pressing","authors":"P. P. Barvitskyi,&nbsp;T. O. Prikhna,&nbsp;H. Ünsal,&nbsp;V. E. Moshchil,&nbsp;M. Hičák,&nbsp;P. Tatarko,&nbsp;M. V. Karpets,&nbsp;A. S. Lokatkina,&nbsp;V. M. Kolodnitskyi,&nbsp;V. V. Bilorusets,&nbsp;S. S. Ponomaryov,&nbsp;L. M. Devin,&nbsp;S. V. Rychev,&nbsp;O. V. Prysiazhna,&nbsp;A. A. Marchenko","doi":"10.3103/S106345762601017X","DOIUrl":"10.3103/S106345762601017X","url":null,"abstract":"<p>The effect of the content of SiC additives to HfB₂ and their physicochemical properties (grain morphology and size of SiC powders, content and composition of their impurities, 6H or β crystal structure) on the level of compaction in hot-pressed ultra-high-temperature HfB₂–SiC composites, their mechanical properties (hardness, fracture toughness, Young modulus), and heat resistance (resistance to ablation) under heating in air to high temperature with a gas burner was studied. The Vickers microhardness <i>H</i>_V and fracture toughness <i>K</i>_Ic of the best from the developed composites were, respectively, <i>H</i>_V = 38.6 ± 2.5 GPa and <i>K</i>_Ic = 7.7 ± 0.9 MPa m^0.5 (after the indentor load of 9.8 N), and the Young modulus is 510 GPa. This composite was synthesized from a HfB₂–30 wt % SiC (5–10 µm) mixture under hot pressing (at a pressure of 30 MPa, 1950°C, 30 min) and had a density of 6.54 g/cm³. The studies of resistance to ablation in air for hot-pressed HfB₂ and HfB₂–SiC specimens heated with a gas burner show that HfB₂ ceramic with addition of 30 wt % SiC and an average grain size of 30–50 µm (clastic grains with sharp edges and an approximate stoichiometry SiC_1.6O_0.1, 6_H SiC) and 5–10 µm (single-crystal grains with a hypercubic nearly spherical shape almost free from impurities with an approximate stoichiometry SiC_1,5, β-SiC) are highly refractory: they are resistant to the temperatures of 2766 and 2780°C, respectively, at a mass loss of 0.25 mg/s as compared to the HfB₂ ceramic free from additives, the specimens from which were cracked as soon as at a temperature of 1870°C, and also more resistant than the HfB₂–30 wt % SiC ceramic synthesized with addition of SiC with sharp clastic grains with a size of 1 µm (with a shape lamellar or strongly elongated in one direction and an approximate stoichiometry SiC_4.6O_0.75, 6H-SiC) or 3–10 µm (with an approximate stoichiometry SiC_2.3O_0.25, 6H-SiC), which was cracked as soon as at a temperature of 1787 and 1455°C, respectively. A better heat resistance (resistance to ablation) exhibited by the HfB₂–SiC ceramic with addition of certain SiC types can be explained by high hardness and Young modulus values, the formation of solid solutions on the basis of HfB₂ and SiC phases with a small quantity of impurity oxygen, and the distribution of the present phases over the volume of the composite.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"48 1","pages":"15 - 26"},"PeriodicalIF":1.2,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147352652","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, Thermal Conductivity, and Specific Electrical Resistivity of an Aluminum Nitride–Titanium Nitride Composite Material in the Percolation Region","authors":"V. I. Omelianenko,&nbsp;I. P. Fesenko,&nbsp;L. O. Romanko,&nbsp;S. P. Staryk,&nbsp;O. M. Kaidash,&nbsp;G. S. Oleǐnik,&nbsp;V. I. Chasnyk,&nbsp;V. M. Kolodnitskyi,&nbsp;H. P. Zakharchuk","doi":"10.3103/S1063457626010168","DOIUrl":"10.3103/S1063457626010168","url":null,"abstract":"<p>This study reports the preparation of AlN–TiN ceramic composites with high TiN content, near the percolation threshold, by pressureless sintering and examines their properties. The analysis addresses microstructural characteristics, measured thermal conductivity at room temperature, and electrical resistivity in the 300–700 K temperature range. The study also proposes a mechanism responsible for the drastic change in electrical conductivity in the as-obtained composites.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"48 1","pages":"56 - 64"},"PeriodicalIF":1.2,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147352712","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":"High-Pressure High-Temperature Crystallization of GaN: Modeling and Experimental Studies","authors":"O. P. Liudvichenko,&nbsp;O. O. Lyeshchuk,&nbsp;I. A. Petrusha,&nbsp;S. O. Gordieiev,&nbsp;B. S. Sadovyi,&nbsp;P. S. Sadovyi,&nbsp;Yu. I. Sadova,&nbsp;A. S. Nikolenko,&nbsp;V. Z. Turkevych,&nbsp;S. Porowski,&nbsp;I. Grzegory","doi":"10.3103/S1063457626010144","DOIUrl":"10.3103/S1063457626010144","url":null,"abstract":"<p>Using computational modeling, we optimized the resistive heating process of the high-pressure apparatus (HPA) cell designed for the growth of GaN crystals from the Fe–Ga–N solution-melt under high-pressure and high-temperature (HPHT) conditions via the temperature gradient method. The thermal state of the apparatus was simulated by solving the coupled electro- and heat-conduction problem using the finite element method. Modeling determined the spatial distribution of temperature and temperature gradient within the experimental cell. As a result of computational optimization of the thermal state of the toroid-40 type HPA cell, polycrystalline GaN was synthesized from the Fe–Ga–N solution-melt. Reducing the axial temperature gradient in the crystallization volume from 13 to 1.5°C/mm produced the growth of petal-shaped GaN single crystals. Observed crystal growth rates varied from 40 to 250 µm/h.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"48 1","pages":"43 - 55"},"PeriodicalIF":1.2,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147352649","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":"Efficiency of the Diamond Grinding of Ceramic Balls","authors":"S. V. Sokhan’,&nbsp;V. V. Voznyy,&nbsp;V. H. Sorochenko,&nbsp;O. A. Mikishchenko","doi":"10.3103/S1063457626010193","DOIUrl":"10.3103/S1063457626010193","url":null,"abstract":"<p>For the diamond grinding of ceramic silicon nitride balls, the advantages and shortcomings of performing the process when the balls are based on a plane and in a V-shaped groove under circular feed both with and without oscillation are considered. The reasonability of grinding the balls in a groove under circular feed without oscillation in certain processing regimes to preserve the flat shape of a diamond wheel or eliminate its concavity is shown. It is proposed to increase the efficiency of the diamond grinding of ceramic balls by passing to the process, in which the scheme of basing the balls is varied along with the features of their circular feed with the application of corresponding machining regimes.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"48 1","pages":"65 - 75"},"PeriodicalIF":1.2,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147352713","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":"Polishing Techniques for Optical-Grade Copper and Aluminum Parts","authors":"Yu. D. Filatov,&nbsp;T. O. Prikhna,&nbsp;A. Yu. Boyarintsev,&nbsp;V. I. Sidorko,&nbsp;S. V. Kovalev","doi":"10.3103/S1063457625060073","DOIUrl":"10.3103/S1063457625060073","url":null,"abstract":"<p>This study examines the regularities in polishing optical components made of copper and aluminum using dispersed systems of micro- and nanopowders. The results show that both the material removal rate and the wear intensity of the polishing powder increase with higher <i>Q</i> factors of the microresonator, as well as with longer lifetimes of quantum dots on the polished surface and clusters on the surface of polishing powder particles in the excited state. The volumetric wear coefficients and the most probable sizes of sludge and polishing-powder wear nanoparticles exhibit corresponding trends. The surface roughness parameters <i>R</i>_a, <i>R</i>_q, and <i>R</i>_max increase linearly with the <i>Q</i> factor of the microresonator. Analysis of the dependence of the surface roughness parameter <i>R</i>_<i>z</i> and the η_m/<i>R</i>_a ratio on the most probable size of sludge nanoparticles indicates that using cerium dioxide powder dispersions for copper polishing fails to meet the required standards for optical surfaces, and for aluminum polishing, it does not offer sufficient material removal efficiency. The study substantiates the feasibility of employing copper metaborate micro- and nanopowder dispersions to polish optical copper and aluminum surfaces, achieving the required surface roughness at a high material removal rate. Theoretical values of the material removal rate during polishing with copper metaborate and cerium dioxide dispersions agree well with experimental data, showing a deviation of only 2–5%.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 6","pages":"477 - 486"},"PeriodicalIF":1.2,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145808673","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":"Interaction Mechanisms between TiC and VN under High-Pressure High-Temperature Sintering and Mechanical Alloying","authors":"N. M. Belyavina,&nbsp;V. Z. Turkevich,&nbsp;D. A. Stratiichuk,&nbsp;A. M. Kuryliuk,&nbsp;Ya. M. Romanenko","doi":"10.3103/S1063457625060012","DOIUrl":"10.3103/S1063457625060012","url":null,"abstract":"<p>This study examines the interaction between titanium carbide TiC and nitride vanadium VN during both high-pressure, high-temperature (HPHT) sintering and mechanical alloying in a high-energy planetary mill. An equimolar TiC–VN mixture served as a binder in the synthesis of a PcBN composite with the cBN–TiC–VN–Al system (60 : 17.5 : 17.5 : 5 vol %) and was also used during mechanical alloying. Both synthesis routes produced confined solid solutions, (Ti, V)(C, N) and (V, Ti)N, but through distinct mechanisms: vacancy formation during mechanical alloying and diffusion-driven processes during HPHT sintering. Considering these findings, we propose synthesizing PcBN composites with various Me^IC–Me^IIN binders by applying preliminary mechanochemical treatment until solid solutions form.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 6","pages":"421 - 429"},"PeriodicalIF":1.2,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145808614","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":"Ultrahigh-Temperature TaB2 Based Composite Materials Sintered by Different Methods","authors":"T. O. Prikhna,&nbsp;P. P. Barvitskyi,&nbsp;E. S. Hevorkian,&nbsp;V. E. Moshchil,&nbsp;M. V. Karpets,&nbsp;S. S. Ponomaryov,&nbsp;L. M. Devin,&nbsp;S. V. Rychev,&nbsp;V. M. Kolodnitskyi,&nbsp;M. Rucki,&nbsp;A. S. Lokatkina,&nbsp;O. I. Borimskiy,&nbsp;A. A. Marchenko,&nbsp;L. O. Polikarpova","doi":"10.3103/S1063457625060097","DOIUrl":"10.3103/S1063457625060097","url":null,"abstract":"<p>Sintering processes were studied for TaB₂ and its mixtures with 20 and 30 wt % of SiC, ZrSi₂, and MoSi₂ under hot pressing (HotP) and high pressure–high temperature (HPHT) conditions and TaB₂ and its mixtures with 20 and 30 wt % of SiC under spark plasma sintering (SPS) conditions. The introduction of additives led to the formation of solid solutions on the basis of TaB₂ and SiC and new phases. For TaB₂, the Vickers hardness was <i>Н</i>_V(9.8 N) = 32.4 GPa after HotP and <i>Н</i>_V(49 N) = 20.8 GPa after SPS (1950°C, 0.05 h), and the fracture toughness was <i>K</i>_Ic (49 N) = 7.6 MPa m^0.5. The Young modulus was essentially improved from 532 to 853 GPa by adding 20 wt % of SiC after HotP. Sintering TaB₂ mixtures with 30 wt % of SiC resulted in the materials with <i>Н</i>_V(9.8 N) = 39.4 GPa, <i>K</i>_Ic(9.8 N) = 6.75 MPa m^0.5(HPHT) and <i>Н</i>_V(49 N) = 25.4 GPa, <i>K</i>_Ic(49 N) = 10.8 MPa m^0.5(SPS).</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 6","pages":"494 - 497"},"PeriodicalIF":1.2,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145808615","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 Removal Mechanism of PcBN Material by Femtosecond Laser","authors":"Jialin Liu,&nbsp;Zhibin Lin,&nbsp;Yongqian Chen,&nbsp;Shirui Guo,&nbsp;Yinghao Cui,&nbsp;Xiaolei Li,&nbsp;Bo Zheng,&nbsp;Yue Zhao,&nbsp;Lujun Cui,&nbsp;Shuai Wang,&nbsp;Lei Wang,&nbsp;Minghui Gu,&nbsp;Quanbin Du,&nbsp;Xiaolu Wang","doi":"10.3103/S1063457625060061","DOIUrl":"10.3103/S1063457625060061","url":null,"abstract":"<p>This study compares the material removal mechanisms and thermal effects of femtosecond and nanosecond lasers on polycrystalline cubic boron nitride (PcBN). Using 800 kHz femtosecond and 35 kHz nanosecond lasers, the surface morphology and phase evolution were analyzed via SEM, EDS, and XRD. Results show: femtosecond lasers preferentially remove the AlN binder via ultrashort pulses—evaporation dominates at 0.5 W, while cBN fracture occurs at 1.3 W. Nanosecond lasers induce cBN-to-hBN phase transition and rough surfaces due to thermal accumulation. At 10 W, femtosecond-processed grooves exhibit smooth walls, whereas nanosecond lasers generate cracks and recast layers. XRD confirmed no hBN phase in femtosecond-processed regions, but minor hBN peaks in nanosecond-processed samples. High-repetition-rate femtosecond lasers demonstrate superior performance in minimizing thermal damage and enhancing machining quality.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 6","pages":"467 - 476"},"PeriodicalIF":1.2,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145808613","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":"Performance Characteristics of Diamond-Powder Grinder Tools Obtained through Adhesive–Magnetic Sorting in Liquid","authors":"V. I. Lavrinenko,&nbsp;V. V. Smokvyna,&nbsp;H. D. Ilnytska,&nbsp;V. Yu. Solod","doi":"10.3103/S1063457625060085","DOIUrl":"10.3103/S1063457625060085","url":null,"abstract":"<p>This study demonstrates that using AC20 grinding powder selected for uniformity in grain strength and size through adhesive–magnetic sorting in liquid significantly enhances the wear resistance of diamond wheels by up to sixfold. Wheels fabricated with AC32 grains selected from AC20 powder show a threefold increase in wear resistance, while those with AC50 grains achieve a 1.5-fold improvement. In all cases, wheels produced from selected diamond grains exhibit higher wear resistance than those made from the initial, unsorted AC20 powder. The surface roughness parameter (<i>R</i>_a) of workpieces ground with wheels prepared using different adhesive–magnetic sorting options remains essentially unchanged. However, experiments revealed that wheels containing selected AC32 125/100 grains produce polished surfaces with the lowest holding capacity, a factor that must be considered when using such wheels in grinding applications.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"47 6","pages":"487 - 493"},"PeriodicalIF":1.2,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145808709","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}