Journal of Superhard Materials最新文献

{"title":"Thermal Phenomena on the Front Surface of Tools with PcBN during Turning of Hardened Steel","authors":"S. A. Klymenko,&nbsp;S. An. Klymenko,&nbsp;M. Yu. Kopіeіkina,&nbsp;A. S. Manokhin,&nbsp;Yu. O. Melniychuk","doi":"10.3103/S1063457623050064","DOIUrl":"10.3103/S1063457623050064","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>The paper presents the results of determining the temperature at flash spots on the front surface and the cutting temperature when turning hardened steel with a tool made of PcBN of the BH group. Based on the experimental data on the dimensions of the chip-tool contact area, its topographic characteristics, and the level of loads on the tool’s front surface, a theoretical calculation of the flash point temperature in the tool contact zone was performed. It was found that the change in temperature at the flash spots with increasing cutting speed is extreme: at a cutting speed of 2 m/s, the temperature at the flash spots exceeds 2000°C on the plastic and 1000°C on the elastic parts of the contact area. Using an experimental and computational approach, the level of cutting temperature was determined, which increases with increasing cutting speed and reaches 1200°C. It is proved that, in accordance with the decrease in the temperature at the flash spots when machining at a cutting speed of more than 2 m/s, the intensity of the increase in the cutting temperature, which characterizes the average temperature at the contact area of the tool, decreases.</p></div></div>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"45 5","pages":"388 - 398"},"PeriodicalIF":0.9,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134796250","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":"Vacuum Carbothermal Synthesis of TiB2","authors":"Mehmet Bugdayci,&nbsp; Şeyma Güleç","doi":"10.3103/S1063457623050039","DOIUrl":"10.3103/S1063457623050039","url":null,"abstract":"<p>In this study, the formation conditions of TiB₂, whose main production method is carbothermal reduction, at lower temperatures with additional processes (vacuum, mechanical activation and functional addition effect) were investigated. In this study, firstly the 100% stoichiometric mixture was reduced at 1200°C under vacuum for varying experimental durations. Afterwards, the effect of mechanical activation amount on TiB₂ formation was determined by keeping the 4-h reduction time, which was determined as optimum in the first set of experiments. At the last stage of the experiments, the addition of 2.5 and 5% NaCl effect on the mixtures in the first set of experiments was determined. The samples obtained after the experiment were characterized by XRD and SEM techniques, and it was observed that the undesired phases were completely removed as a result of the reduction performed after 16 h of ball mile operation, and this experiment was determined as the optimum experimental condition.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"45 5","pages":"360 - 369"},"PeriodicalIF":0.9,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134796329","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":"Rate of Material Removal When Processing Titanium-Doped Sapphire","authors":"O. O. Vovk,&nbsp;A. V. Voloshin,&nbsp;E. V. Slyunin,&nbsp;L. I. Voloshina,&nbsp;S. I. Kryvonogov,&nbsp;S. V. Nizhankovskyi","doi":"10.3103/S1063457623050106","DOIUrl":"10.3103/S1063457623050106","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>The effect of the content of titanium ions in the crystals of titanium-doped sapphire (Ti:sapphire, up to 0.2 wt % Ti) on the rate of material removal and surface roughness at different stages of its processing was studied. It was established that the efficiency of material removal increases with an increase in the density of dislocations in the crystal. It was detected that with an increase in the content of titanium in Ti:sapphire during grinding with a fixed abrasive, the rate of material removal decreases, while in the case of grinding and polishing with a free abrasive, it increases due to a disordering of the crystal structure and deterioration of structural perfection of the crystals. Doping of sapphire with titanium leads to a decrease in the value of the crystal surface roughness parameter at a grinding stage.</p></div></div>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"45 5","pages":"379 - 387"},"PeriodicalIF":0.9,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134796247","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":"On Crystal Structure of Superhard Cubic BC2N","authors":"V. L. Solozhenko","doi":"10.3103/S106345762305009X","DOIUrl":"10.3103/S106345762305009X","url":null,"abstract":"<p>Crystal chemistry analysis and accurate calculations of the mechanical properties of the recently proposed cubic diamondlike BC₂N indicate that this hypothetical phase is not related to the experimentally synthesized cubic BC₂N.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"45 5","pages":"399 - 401"},"PeriodicalIF":0.9,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134796251","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":"Features Structure of the Сdiamond‒(WC‒Co)‒ZrO2 Composite Fracture Surface as a Result of Impact Loading","authors":"B. T. Ratov,&nbsp;V. A. Mechnik,&nbsp;N. A. Bondarenko,&nbsp;V. M. Kolodnitskyi,&nbsp;E. S. Gevorkyan,&nbsp;V. P. Nerubaskyi,&nbsp;A. G. Gusmanova,&nbsp;B. V. Fedorov,&nbsp;N. A. Kaldibaev,&nbsp;M. T. Arshidinova,&nbsp;V. G. Kulych","doi":"10.3103/S1063457623050088","DOIUrl":"10.3103/S1063457623050088","url":null,"abstract":"<div><div><h3>\u0000 <b>Abstract</b>—</h3><p>The effect of the addition of ZrO₂ micropowder (in the range from 0 to 10%) on the structural changes of the hard alloy matrix in the area of fracture as a result of impact loading of a sample of composite diamond-containing material (DCM) 25С_diamond–70.5WC‒4.5Co wt % was studied, formed by the method of spark plasma sintering in the temperature range from 20 to 1350°С at a pressure of 30 MPa for 3 min. It was found that in the DCM sample without ZrO₂ additive, the structure of the hard alloy matrix has the appearance characteristic of brittle fracture, which is evidenced by the smooth relief of the fracture surface. In this case, the destruction of the DCM sample occurs by chipping of the components of the hard alloy matrix, which leads to a decrease in its wear resistance. The introduction of the ZrO₂ additive in the amount of 4% into the composition of DCM causes a change in the structure of the fracture surface. On the fracture surface of the carbide matrix of the DCM sample, nanopores with a structural size of ~100–500 nm are formed as a result of viscous (pitting) fracture. At the same time, in addition to the formation of dimples on the fracture surface of the hard alloy matrix, a highly developed relief is simultaneously formed on the surface of the diamond grain, which is evidence of improved diamond retention and increased wear resistance of the composite. With a further increase to 10% of the ZrO₂ additive in the DCM composition, a more pronounced microrelief with the presence of deep dimples and microcracks is formed on the fracture surfaces of the hard alloy matrix and diamond grain. It is proposed to use the type of relief of the fracture surface of sintered DCM samples during impact fracture at room temperature as an assessment of the characteristics of the strength of diamond retention.</p></div></div>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"45 5","pages":"348 - 359"},"PeriodicalIF":0.9,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134796328","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":"Specific Features of Measuring the Elasticity Modulus and the Decrement of Oscillations in Superhard Material Polycrystals by the Dynamic Method","authors":"L. M. Devin,&nbsp;M. P. Bezhenar,&nbsp;S. V. Rychev","doi":"10.3103/S1063457623040032","DOIUrl":"10.3103/S1063457623040032","url":null,"abstract":"<p>The resonant frequencies of natural oscillations in disk-shaped specimens are determined as a function of the elasticity modulus and dimensions of a specimen. The effect produced by the specimen fastening place on the precision of measuring the elasticity modulus and the decrement of oscillation in the series of cubic boron nitride/diamond polycrystal specimens are estimated. All the considered variants of sintered polycrystals can be classified into three groups depending on the diamond powder content. The properties (elasticity modulus, oscillation decrement, sound velocity, Q factor) are different for each of these groups of polycrystals.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"45 4","pages":"249 - 254"},"PeriodicalIF":0.9,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41084109","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":"First Principles Search for Novel Ultrahard High-Density Carbon Allotropes: Hexagonal C6, C9, and C12","authors":"Samir F. Matar,&nbsp;Vladimir L. Solozhenko","doi":"10.3103/S1063457623040056","DOIUrl":"10.3103/S1063457623040056","url":null,"abstract":"<p>Hexagonal carbon allotropes C₆, C₉, and C₁₂ with <b>qtz</b>, <b>sta</b> and <b>lon</b> topologies, respectively, were predicted on the basis of crystal chemistry and first principles (DFT) calculations. The new allotropes are mechanically (elastic properties) and dynamically (phonons) stable phases and are characterized by ultra-high Vickers hardness, exceptionally high for <b>qtz</b> C₆ and C₁₂, close to the previously studied <b>qtz</b> C₃. The electronic band structures of all new allotropes show semi-conducting to insulating behavior. <b>lon</b> C₁₂ can be considered as novel “superlonsdaleite.”</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"45 4","pages":"239 - 248"},"PeriodicalIF":0.9,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41084070","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 Al2O3 and Yb2O3 on Mechanical Performances and Thermal Shock Behaviors of Zirconia Composites Prepared by SPS","authors":"Junlong Sun,&nbsp;Weifu Zhao,&nbsp;Zhizhen Li,&nbsp;Bin Li,&nbsp;Changxia Liu","doi":"10.3103/S1063457623040081","DOIUrl":"10.3103/S1063457623040081","url":null,"abstract":"<p>ZrO₂–Y₂O₃ composites with different content of Al₂O₃–Yb₂O₃ additives were fabricated by spark plasma sintering (SPS). The effect of Al₂O₃ and Yb₂O₃ additives on the mechanical performance, phase transformation, thermal shock resistance and microstructure of ZrO₂–Y₂O₃ composites was researched. The addition of Al₂O₃ and Yb₂O₃ contributed to enhancing the phase transformation and densification of ZrO₂–Y₂O₃ composites fabricated by SPS. ZrO₂–Y₂O₃ composites possessed the optimum comprehensive performances as the content of Al₂O₃ and Yb₂O₃ is 10 and 4 wt %, respectively. The thermal shock resistance (TSR), hardness, toughness, strength and relative density could achieved of 344°C, 13.6 GPa, 5.7 MPa m^1/2, 900 MPa, and 99.5%. The combination of refinement of grain size, changing of fracture mode, enhancement of density, phase transformation contributed to the improvement in TSR and mechanical performances of ZrO₂–Y₂O₃ composites fabricated by SPS.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"45 4","pages":"255 - 265"},"PeriodicalIF":0.9,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41084107","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":"Diamond Grinding of Ceramic Balls with a Circular Feed","authors":"S. V. Sokhan’,&nbsp;V. V. Voznyy,&nbsp;V. H. Sorochenko,&nbsp;M. P. Hamaniuk","doi":"10.3103/S106345762304007X","DOIUrl":"10.3103/S106345762304007X","url":null,"abstract":"<p>The results of an experimental study of the effect of the processing mode on the wear of the diamond wheel surface and the accuracy of the ball shapes are described for diamond grinding of ceramic balls made of silicon nitride with a circular feed. The angle of inclination of the working surface in the radial direction, the curvature coefficient, and the accuracy of the shape of the polished balls, i.e., the instability of the ball diameter and the form factor of the round profilogram, are taken as wear indices of the wheel surface. The observed effects are described by adequate linear dependences of the angle of inclination and the curvature coefficient on the frequency of feeding the workpieces, the instability of the ball diameter on the wheel rotation frequency, and the form factor on both parameters. Combinations of the processing mode parameters within the studied range of changes are determined, which served as a basis for the subsequent optimization of the indicated parameter values.</p>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"45 4","pages":"293 - 305"},"PeriodicalIF":0.9,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41084110","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":"Characteristics, Machinability Modeling, and Machining Performance Improvement of Graphene Reinforced Al-MMC Using CRSM and Utility Method","authors":"Manojit Das,&nbsp;Soumya R. Parimanik,&nbsp;Trupti Ranjan Mahapatra,&nbsp;Debadutta Mishra,&nbsp;Dilip Kumar Sahu","doi":"10.3103/S1063457623040020","DOIUrl":"10.3103/S1063457623040020","url":null,"abstract":"<div><div><h3>A</h3><p><b>bstract</b>—The present experimental research examines the machinability of graphene-based aluminium metal matrix composite (AMMC) using a polycrystalline diamond (PCD) carbide-insert tool under a dry environment and compared it with that of pure aluminium. The AMMCs are synthesized by reinforcing 0, 0.5, 1, 2, and 3 wt % of graphene particles via the stir casting process and are characterized for their density, tensile, compression, micro-hardness, and morphological properties. Response optimization is performed to minimize the two surface roughness factors (<i>R</i>_<i>a</i> and <i>R</i>_<i>z</i>), power consumption and vibration (average acceleration). The central composite design-based response surface methodology (CRSM) is implemented for planification of the experimentation and subsequent higher-order regression response modelling of the actual process outputs is obtained. The characterization and machinability of AMMCs incorporating higher (1, 2, and 3 wt %) of graphene is first time investigated alongside multi-performance (<i>R</i>_<i>a</i>, <i>R</i>_<i>z</i>, power consumption, and vibration) optimization. The optimal combination of the process parameters resulting in simultaneous minimization of all the responses is also acquired using the Utility concept, compared to those obtained using the desirability approach in RSM and validated by conducting the confirmatory test. Improvement in surface roughness values (7.85 and 36.26% for <i>R</i>_<i>a</i> and <i>R</i>_<i>z</i>, respectively) and average acceleration (18.09%) are observed via the Utility method in comparison to the CRSM. Enhanced output results in comparison to pure aluminium are also observed.</p></div></div>","PeriodicalId":670,"journal":{"name":"Journal of Superhard Materials","volume":"45 4","pages":"266 - 292"},"PeriodicalIF":0.9,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41084119","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}