Pub Date : 2023-12-01DOI: 10.15407/materials2023.07.011
V. Tytarenko, V. Zabludovsky, Y. O. Koshman
The problem of joint electrolytic deposition of metal ions and ultradispersed diamond particles into a metal matrix is formulated. The mathematical model describing the mechanism and kinetics of the cathodic process, the mass transfer of metal ions and carbon nanomaterial particles is developed. It has been established that transfer of particles of the dispersed phase occurs mainly not by the diffusion mechanism but under the influence of an electric field. Keywords: ultradispersed diamond particles, electrodeposition, composite electrolytic coatings.
{"title":"Mechanism of incorporation of carbon nanomaterial particles in composite electrolytic metal coating","authors":"V. Tytarenko, V. Zabludovsky, Y. O. Koshman","doi":"10.15407/materials2023.07.011","DOIUrl":"https://doi.org/10.15407/materials2023.07.011","url":null,"abstract":"The problem of joint electrolytic deposition of metal ions and ultradispersed diamond particles into a metal matrix is formulated. The mathematical model describing the mechanism and kinetics of the cathodic process, the mass transfer of metal ions and carbon nanomaterial particles is developed. It has been established that transfer of particles of the dispersed phase occurs mainly not by the diffusion mechanism but under the influence of an electric field. Keywords: ultradispersed diamond particles, electrodeposition, composite electrolytic coatings.","PeriodicalId":509971,"journal":{"name":"Uspihi materialoznavstva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139192084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.15407/materials2023.07.004
Y. Podrezov, N. V. Minakov, B. V. Shurigin, A. A. Golubenko, K. E. Grinkevich, M. G. Askerov, K. Gogaev
Features of strengthening of the near-surface layer of ADI during friction due to strain-induced martensitic transformation were analyzed by duromeric methods. Indentation under continuous loading (Meyer hardness, HM) and Vickers microhardness Hμ were used. Pop–ins are observed on the ADI continuous load curves, which indicate martensitic transformations during indentation. The effect usually exists at a load of ~0,1 H and an depth of ~1,5 μk. The average microhardness of the initial sample is Hμ ≈ 4,89 GPa. After wear, the average value increases to Hμ ≈ 6,92 GPa. Statistical analysis of the microhardness distribution of the sample after wear revealed that a third of the indentations have abnormally high hardness, which is characteristic of deformation-induced martensite. Probably, these indents are obtained from regions of the structure where deformation-induced martensitic transformation took place. Increasing the indentation load practically does not affect the determination of the microhardness of the initial sample, but reduces the hardness of the sample after wear. This indicates the gradient nature of deformation and phase-structural rearrangements in the near-surface layer during wear. As the friction temperature increases, there is a decrease in microhardness in the wear zone. This is explained by the departure from the temperature range of the martensitic transformation, due to which the TRIP effect is weakened. The maximum degradation of microhardness is observed between room temperature and 50 oC. Keywords: ADI materials, durometric studies, TRIP-effect, wear.
采用硬质合金方法分析了 ADI 在摩擦过程中由于应变诱导的马氏体转变而导致近表面层强化的特征。使用了连续加载下的压痕（迈耶硬度，HM）和维氏显微硬度 Hμ。在 ADI 连续加载曲线上观察到了弹入现象，这表明压痕过程中发生了马氏体转变。这种效应通常存在于 ~0.1 H 的载荷和 ~1.5 μk 的深度时。初始样品的平均显微硬度为 Hμ ≈ 4,89 GPa。磨损后，平均值增至 Hμ ≈ 6,92 GPa。对磨损后样品显微硬度分布的统计分析显示，三分之一的压痕具有异常高的硬度，这是变形诱导马氏体的特征。这些压痕可能来自发生变形诱导马氏体转变的结构区域。增加压痕载荷实际上不会影响初始试样显微硬度的测定，但会降低磨损后试样的硬度。这表明磨损过程中近表面层的变形和相结构重排具有梯度性。随着摩擦温度的升高，磨损区的显微硬度会降低。这是因为偏离了马氏体转变的温度范围，从而削弱了 TRIP 效应。显微硬度的最大降幅出现在室温至 50 oC 之间。关键词ADI 材料、硬度计研究、TRIP 效应、磨损。
{"title":"Durometric analysis of hardening of the near-surface layer of ADI during friction at the influence of the TRIP effect","authors":"Y. Podrezov, N. V. Minakov, B. V. Shurigin, A. A. Golubenko, K. E. Grinkevich, M. G. Askerov, K. Gogaev","doi":"10.15407/materials2023.07.004","DOIUrl":"https://doi.org/10.15407/materials2023.07.004","url":null,"abstract":"Features of strengthening of the near-surface layer of ADI during friction due to strain-induced martensitic transformation were analyzed by duromeric methods. Indentation under continuous loading (Meyer hardness, HM) and Vickers microhardness Hμ were used. Pop–ins are observed on the ADI continuous load curves, which indicate martensitic transformations during indentation. The effect usually exists at a load of ~0,1 H and an depth of ~1,5 μk. The average microhardness of the initial sample is Hμ ≈ 4,89 GPa. After wear, the average value increases to Hμ ≈ 6,92 GPa. Statistical analysis of the microhardness distribution of the sample after wear revealed that a third of the indentations have abnormally high hardness, which is characteristic of deformation-induced martensite. Probably, these indents are obtained from regions of the structure where deformation-induced martensitic transformation took place. Increasing the indentation load practically does not affect the determination of the microhardness of the initial sample, but reduces the hardness of the sample after wear. This indicates the gradient nature of deformation and phase-structural rearrangements in the near-surface layer during wear. As the friction temperature increases, there is a decrease in microhardness in the wear zone. This is explained by the departure from the temperature range of the martensitic transformation, due to which the TRIP effect is weakened. The maximum degradation of microhardness is observed between room temperature and 50 oC. Keywords: ADI materials, durometric studies, TRIP-effect, wear.","PeriodicalId":509971,"journal":{"name":"Uspihi materialoznavstva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139195497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.15407/materials2023.07.008
O. Durov, V. Poluyanska, T. Stetsyuk
Zinc oxide is a wide-gap semiconductor with unique properties, used for the manufacture of catalysts, electrodes, transistors, etc. In these applications, there is a need for metallization and joining of ZnO-based materials, using of molten metal filler is an effective method. Contact of zinc oxide and liquid metals is almost not studied in comparison to other oxide materials. In this work the wetting of zinc oxide based ceramic with metal melts of the silver-copper system in high vacuum was studied. Alloys with concentration of copper (% (at.)) 0 (pure silver), 5, 10, 20, 30, 39, 100 (pure copper) were used. Increasing the concentration of copper in the silver-copper melts significantly improves the wetting of ZnO-ceramic with these liquids, the contact angles decrease from 137° for the pure silver to 28° for the pure copper. Investigations of the microstructure show presence of relatively thin transition layers on the interfaces for silver-copper alloys, for the pure copper case the interface has complex “island-like” microstructure. Also a ruination of ZnO-ceramic substrates due to an interaction with metal melt was noted, the higher copper concentration, the more intensive ruination. Also some signs of the presence of zinc in the metal drops solidified on the zinc oxide surface were revealed, such as, intensive oxidation of the drops in air at room temperature. The oxidation shows complex multiphase microstructure of the solidified drops. After wetting of the zinc oxide with pure copper the solidified metal has microstructure of brass (Cu—Zn alloy) with low zinc concentration. The effects observed can be explained by sublimation of the zinc oxide under experimental conditions (high temperatures, vacuum) with formation of gaseous products (oxygen and vapor of zinc), which subsequently dissolve in silver-copper liquid drops. In particular, the dissolution of oxygen in the Ag—Cu melt improves its wetting of surfaces of solid oxides and presence of zinc in solidified drops provides its oxidization in air. Keywords: zinc oxide, wetting with metals, contact interaction, microstructure, transition layer.
{"title":"Wetting of ZnO-ceramic with alloys of the silver-copper system in vacuum","authors":"O. Durov, V. Poluyanska, T. Stetsyuk","doi":"10.15407/materials2023.07.008","DOIUrl":"https://doi.org/10.15407/materials2023.07.008","url":null,"abstract":"Zinc oxide is a wide-gap semiconductor with unique properties, used for the manufacture of catalysts, electrodes, transistors, etc. In these applications, there is a need for metallization and joining of ZnO-based materials, using of molten metal filler is an effective method. Contact of zinc oxide and liquid metals is almost not studied in comparison to other oxide materials. In this work the wetting of zinc oxide based ceramic with metal melts of the silver-copper system in high vacuum was studied. Alloys with concentration of copper (% (at.)) 0 (pure silver), 5, 10, 20, 30, 39, 100 (pure copper) were used. Increasing the concentration of copper in the silver-copper melts significantly improves the wetting of ZnO-ceramic with these liquids, the contact angles decrease from 137° for the pure silver to 28° for the pure copper. Investigations of the microstructure show presence of relatively thin transition layers on the interfaces for silver-copper alloys, for the pure copper case the interface has complex “island-like” microstructure. Also a ruination of ZnO-ceramic substrates due to an interaction with metal melt was noted, the higher copper concentration, the more intensive ruination. Also some signs of the presence of zinc in the metal drops solidified on the zinc oxide surface were revealed, such as, intensive oxidation of the drops in air at room temperature. The oxidation shows complex multiphase microstructure of the solidified drops. After wetting of the zinc oxide with pure copper the solidified metal has microstructure of brass (Cu—Zn alloy) with low zinc concentration. The effects observed can be explained by sublimation of the zinc oxide under experimental conditions (high temperatures, vacuum) with formation of gaseous products (oxygen and vapor of zinc), which subsequently dissolve in silver-copper liquid drops. In particular, the dissolution of oxygen in the Ag—Cu melt improves its wetting of surfaces of solid oxides and presence of zinc in solidified drops provides its oxidization in air. Keywords: zinc oxide, wetting with metals, contact interaction, microstructure, transition layer.","PeriodicalId":509971,"journal":{"name":"Uspihi materialoznavstva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139195660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.15407/materials2023.07.012
O. M. Grigoriev, V. Vinokurov, L. I. Klimenko, N. Bega
A study was carried out of the processes of compaction, structure formation and mechanical properties of ceramics based on zirconium boride with sintering-activating additives of boron, silicon and chromium carbides, as well as molybdenum silicide, obtained under hot pressing conditions in a CO atmosphere. In ZrB2—18% (vol.) B4C ceramics, the use of the B4C additive reduces the optimal hot pressing temperature to 1940 °C and accelerates the compaction process of the ceramics. The influence of the sample preparation background on high-temperature creep has been established, as a result of which either plastic flow of the material occurs over a wide temperature range, or a high temperature threshold for yield and brittle fracture. In ZrB2—SiC ceramics, during high-temperature plastic deformation both during sintering and in creep tests, a bidisperse structure with a submicrograined component is formed, which is responsible for high creep rates. In ZrB2—B4C ceramics there is no submicrograin component, which provides high creep resistance up to 2000 °C. The phase composition of ZrB2—MoSi2 ceramics changes dramatically during hot pressing; it is represented by a composition of a ZrB2 solid solution with the second phases of SiC and B4C, and in terms of creep resistance it occupies an intermediate position between two other ceramics. Keywords: ultra-high temperature ceramics, zirconium diboride, silicon, boron and chromium carbides, hot pressing in a CO atmosphere, compaction kinetics, structure, creep resistance.
{"title":"ZrB2 ceramics with MoSi2, SiC and B4C additives: compaction kinetics, phase formation and creep resistance","authors":"O. M. Grigoriev, V. Vinokurov, L. I. Klimenko, N. Bega","doi":"10.15407/materials2023.07.012","DOIUrl":"https://doi.org/10.15407/materials2023.07.012","url":null,"abstract":"A study was carried out of the processes of compaction, structure formation and mechanical properties of ceramics based on zirconium boride with sintering-activating additives of boron, silicon and chromium carbides, as well as molybdenum silicide, obtained under hot pressing conditions in a CO atmosphere. In ZrB2—18% (vol.) B4C ceramics, the use of the B4C additive reduces the optimal hot pressing temperature to 1940 °C and accelerates the compaction process of the ceramics. The influence of the sample preparation background on high-temperature creep has been established, as a result of which either plastic flow of the material occurs over a wide temperature range, or a high temperature threshold for yield and brittle fracture. In ZrB2—SiC ceramics, during high-temperature plastic deformation both during sintering and in creep tests, a bidisperse structure with a submicrograined component is formed, which is responsible for high creep rates. In ZrB2—B4C ceramics there is no submicrograin component, which provides high creep resistance up to 2000 °C. The phase composition of ZrB2—MoSi2 ceramics changes dramatically during hot pressing; it is represented by a composition of a ZrB2 solid solution with the second phases of SiC and B4C, and in terms of creep resistance it occupies an intermediate position between two other ceramics. Keywords: ultra-high temperature ceramics, zirconium diboride, silicon, boron and chromium carbides, hot pressing in a CO atmosphere, compaction kinetics, structure, creep resistance.","PeriodicalId":509971,"journal":{"name":"Uspihi materialoznavstva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139191274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.15407/materials2023.07.006
A. O. Makudera, S. Lakiza, O. V. Dudnik
Based on the analysis of literature data from the experimentally constructed phase diagrams of CeO2—Ln2O3 systems (Ln = Tb—Lu), as well as the temperatures of polymorphic transformations of oxides of rare earth elements (REEs), approximate phase diagrams of the indicated system were constructed in the entire range of temperatures and concentrations. Cerium dioxide crystallizes in the cubic type of fluorite crystal lattice and has no polymorphic transformations in the entire temperature range until melting at 2400 ºC. The solubility based on CeO2 is higher than based on other lanthanide oxides. The components of the systems show complete solubility below solidus with the formation of solid solutions with a structure of the fluorite-type F. The appearance below the solidus regions of solid solutions based on polymorphic modifications of lanthanide oxides H, A, B and C with different width leads to the formation of cascades of peritectoid transformations. During the transition in the Tb—Lu series, their temperatures gradually increase, which is associated with an increase in the temperatures of polymorphic transformations of Tb—Lu oxides. Hypothetical phase diagrams of the CeO2—Ln2O3 series (Ln = Tb—Lu, Y) with adjustments according to such regularities of interaction during the transition from Tb to Lu. Experimental verification of the phase diagrams structure of the considered systems is possible when conducting experiments using increased pressures of oxygen-containing media, or by thermodynamic calculations. Keywords: REE oxides, Y2O3, CeO2, polymorphic transformation of REE, phase diagrams.
{"title":"Hypothetical CeO2—Ln2O3 phase diagrams (Ln = yttrium lanthanides, Y2O3)","authors":"A. O. Makudera, S. Lakiza, O. V. Dudnik","doi":"10.15407/materials2023.07.006","DOIUrl":"https://doi.org/10.15407/materials2023.07.006","url":null,"abstract":"Based on the analysis of literature data from the experimentally constructed phase diagrams of CeO2—Ln2O3 systems (Ln = Tb—Lu), as well as the temperatures of polymorphic transformations of oxides of rare earth elements (REEs), approximate phase diagrams of the indicated system were constructed in the entire range of temperatures and concentrations. Cerium dioxide crystallizes in the cubic type of fluorite crystal lattice and has no polymorphic transformations in the entire temperature range until melting at 2400 ºC. The solubility based on CeO2 is higher than based on other lanthanide oxides. The components of the systems show complete solubility below solidus with the formation of solid solutions with a structure of the fluorite-type F. The appearance below the solidus regions of solid solutions based on polymorphic modifications of lanthanide oxides H, A, B and C with different width leads to the formation of cascades of peritectoid transformations. During the transition in the Tb—Lu series, their temperatures gradually increase, which is associated with an increase in the temperatures of polymorphic transformations of Tb—Lu oxides. Hypothetical phase diagrams of the CeO2—Ln2O3 series (Ln = Tb—Lu, Y) with adjustments according to such regularities of interaction during the transition from Tb to Lu. Experimental verification of the phase diagrams structure of the considered systems is possible when conducting experiments using increased pressures of oxygen-containing media, or by thermodynamic calculations. Keywords: REE oxides, Y2O3, CeO2, polymorphic transformation of REE, phase diagrams.","PeriodicalId":509971,"journal":{"name":"Uspihi materialoznavstva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139191696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.15407/materials2023.07.007
V. S. Zhuravlev, V. P. Krasovskyy
Activation of filler metal alloys for brazing non-metals by introducing chemically active elements such as titanium, zirconium, etc. is a technically challenging task. This paper discusses some methods of brazing non-metallic materials with filler metal alloys. A brief review of publications on the metallisation of non-metallic materials by titanium friction for further brazing with filler metal alloys is given. Two types of titanium foil tools for friction coatings on non-metallic materials have been proposed and used, which, in comparison with friction with compact titanium, significantly reduce the destruction of the ceramic surface and facilitate their application. Samples of high-alumina ceramics A995 and WK94-1, were metallized by the proposed method. The wetting of ceramics coated with PSr72 filler alloy (copper-silver eutectic) was studied, brazed joints were obtained, and the microstructure of the metal-nonmetal contact zone was studied The main purpose of such a coating for brazing processes is to activate the filler metal alloys melt to wet the ceramic. The surface roughness of non-metals affects the microstructure of the applied coating. As the roughness decreases, the density of the coating increases. Studies of the microstructure of the brazed joint have shown that the PSr72 melt penetrates the titanium coating, saturates it with titanium and wets the ceramic. This means that such metallisation accelerates the saturation of the melt with titanium. The brazing modes of this method practically coincide with the brazing modes of titanium-containing filler metal alloys Using the method of friction the metallization layer reduces the cost of the brazing process. Keywords: rubbing with metals, titanium foil, soldering of ceramics, metal solders, microstructure.
{"title":"The use of titanium in the form of a foil for rubbing non-metallic materials with the purpose of wetting them and soldering them with metal solders","authors":"V. S. Zhuravlev, V. P. Krasovskyy","doi":"10.15407/materials2023.07.007","DOIUrl":"https://doi.org/10.15407/materials2023.07.007","url":null,"abstract":"Activation of filler metal alloys for brazing non-metals by introducing chemically active elements such as titanium, zirconium, etc. is a technically challenging task. This paper discusses some methods of brazing non-metallic materials with filler metal alloys. A brief review of publications on the metallisation of non-metallic materials by titanium friction for further brazing with filler metal alloys is given. Two types of titanium foil tools for friction coatings on non-metallic materials have been proposed and used, which, in comparison with friction with compact titanium, significantly reduce the destruction of the ceramic surface and facilitate their application. Samples of high-alumina ceramics A995 and WK94-1, were metallized by the proposed method. The wetting of ceramics coated with PSr72 filler alloy (copper-silver eutectic) was studied, brazed joints were obtained, and the microstructure of the metal-nonmetal contact zone was studied The main purpose of such a coating for brazing processes is to activate the filler metal alloys melt to wet the ceramic. The surface roughness of non-metals affects the microstructure of the applied coating. As the roughness decreases, the density of the coating increases. Studies of the microstructure of the brazed joint have shown that the PSr72 melt penetrates the titanium coating, saturates it with titanium and wets the ceramic. This means that such metallisation accelerates the saturation of the melt with titanium. The brazing modes of this method practically coincide with the brazing modes of titanium-containing filler metal alloys Using the method of friction the metallization layer reduces the cost of the brazing process. Keywords: rubbing with metals, titanium foil, soldering of ceramics, metal solders, microstructure.","PeriodicalId":509971,"journal":{"name":"Uspihi materialoznavstva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139191697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.15407/materials2023.07.001
.M. I. Lugovy, D. Verbylo, M. Brodnikovskyy
A method has been developed in which atomic sizes misfit and elastic modulus misfit at crystal lattice nodes are considered as discrete random variables and the definition of their dispersion allows to obtain analytical expressions for standard deviations and correlation lengths of the short- and long-wave components of stochastic shear stress field created by solute atoms in the glide plane in a multicomponent alloy. This makes it possible to significantly reduce the amount of calculations when determining the shear stress field parameters. The developed method was applied to calculate these parameters for the CrCoNiFeMn alloy. The calculated parameters were well correlated with similar parameters determined from the analysis of shear stress distributions in the glide plane, which were calculated by the method of direct summation of solute atoms contributions. In addition, it was found that there are separate effective crystal lattice distortions for the short- and long-wave components that differ from the average distortion that was proposed earlier. This results from the fact that these components are determined by solute atoms with different distance from the glide plane. Effective distortion is greater, the greater this distance from the glide plane. In addition, there is no single empirical constant for all alloy to determine the yield strength as a function of their shear modulus and average distortion. But the proposed method makes it possible to determine the main parameters of the shear stress field in a specific multicomponent alloy. These parameters can be used to calculate the yield strength of this alloy. Keywords: shear stress, multicomponent alloy, glide plane, solid solution.
{"title":"Statistical method for determining shear stress field parameters in glide plane in multicomponent alloy","authors":".M. I. Lugovy, D. Verbylo, M. Brodnikovskyy","doi":"10.15407/materials2023.07.001","DOIUrl":"https://doi.org/10.15407/materials2023.07.001","url":null,"abstract":"A method has been developed in which atomic sizes misfit and elastic modulus misfit at crystal lattice nodes are considered as discrete random variables and the definition of their dispersion allows to obtain analytical expressions for standard deviations and correlation lengths of the short- and long-wave components of stochastic shear stress field created by solute atoms in the glide plane in a multicomponent alloy. This makes it possible to significantly reduce the amount of calculations when determining the shear stress field parameters. The developed method was applied to calculate these parameters for the CrCoNiFeMn alloy. The calculated parameters were well correlated with similar parameters determined from the analysis of shear stress distributions in the glide plane, which were calculated by the method of direct summation of solute atoms contributions. In addition, it was found that there are separate effective crystal lattice distortions for the short- and long-wave components that differ from the average distortion that was proposed earlier. This results from the fact that these components are determined by solute atoms with different distance from the glide plane. Effective distortion is greater, the greater this distance from the glide plane. In addition, there is no single empirical constant for all alloy to determine the yield strength as a function of their shear modulus and average distortion. But the proposed method makes it possible to determine the main parameters of the shear stress field in a specific multicomponent alloy. These parameters can be used to calculate the yield strength of this alloy. Keywords: shear stress, multicomponent alloy, glide plane, solid solution.","PeriodicalId":509971,"journal":{"name":"Uspihi materialoznavstva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139193889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.15407/materials2023.07.005
I. O. Marek, O. V. Dudnik, V. A. Vynar, V. P. Red’ko, O. K. Ruban
The low-temperature phase stability of materials in the ZrO2—Y2O3—CeO2 system with compositions, % (mol.): 97ZrO2—3Y2O3; 95ZrO2—3Y2O3—2CeO2; 92,5ZrO2—2,5Y2O3—5CeO2; 90ZrO2—2Y2O3—8CeO2; 88ZrO2—12CeO2 was studied. Treatment of materials in hydrothermal conditions under an increased holding time (14 hours) was used. The starting powders were produced by the hydrothermal synthesis in an alkaline medium and heat-treated at 850 °C. The samples were sintered at 1350 oC. The materials properties were investigated by the X-ray phase analysis and electron microscopy. The aging stability of ceramics was determined by the degree of phase transformation T-ZrO2 → M-ZrO2 under experimental conditions. Porous microstructures were formed in the samples, which differ in the size distribution of both grains and pores. A characteristic feature is the presence of various amounts of fine-grained fragments with a regular microstructure and the formation of both rounded and elongated grains.The phase transformation T-ZrO2 → M-ZrO2 leads to an increase of the samples porosity. This, in turn, contributes to the intensification of the ceramics aging. After 14 h the phase transformation T-ZrO2 → M-ZrO2 was found in four samples. In the sample 97ZrO2—3Y2O3, 46% of M-ZrO2 was formed; in the 95ZrO2—3Y2O3—2CeO2 sample, 48% of M-ZrO2 was formed; in the 92,5ZrO2—2,5Y2O3—5CeO2 sample, 39% of M-ZrO2 was formed. In the 90ZrO2—2Y2O3–8CeO2 sample ≈1% of M-ZrO2 appeared, and in the 88ZrO2—12CeO2 sample M-ZrO2 was not identified. Formation features of the solid solution during the doping of zirconia with yttrium oxide and cerium oxide, the amount of cerium oxide in a ZrO2-based solid solution, the phase transformation F-ZrO2 → T-ZrO2 during the sintering and the formation of a homogeneous microstructure contribute to increasing the low-temperature phase stability of samples both 90ZrO2—2Y2O3—8CeO2 and 88ZrO2—12CeO2 composition. During the microstructural design of ceramics in the ZrO2—Y2O3—CeO2 system with increased low-temperature phase stability, it is necessary to establish such a ratio of Y2O3 and CeO2 in the solid solution based on ZrO2 that would provide the necessary strength behavior according to the ceramics use. Keywords: ZrO2—Y2O3—CeO2 system, ZrO2-based solid solution, M-ZrO2 phase, aging, low-temperature phase stability.
{"title":"Low-temperature phase stability of ceramics in the ZrO2—Y2O3—CeO2 system produced after heat treatment of the starting powders at 850 °C","authors":"I. O. Marek, O. V. Dudnik, V. A. Vynar, V. P. Red’ko, O. K. Ruban","doi":"10.15407/materials2023.07.005","DOIUrl":"https://doi.org/10.15407/materials2023.07.005","url":null,"abstract":"The low-temperature phase stability of materials in the ZrO2—Y2O3—CeO2 system with compositions, % (mol.): 97ZrO2—3Y2O3; 95ZrO2—3Y2O3—2CeO2; 92,5ZrO2—2,5Y2O3—5CeO2; 90ZrO2—2Y2O3—8CeO2; 88ZrO2—12CeO2 was studied. Treatment of materials in hydrothermal conditions under an increased holding time (14 hours) was used. The starting powders were produced by the hydrothermal synthesis in an alkaline medium and heat-treated at 850 °C. The samples were sintered at 1350 oC. The materials properties were investigated by the X-ray phase analysis and electron microscopy. The aging stability of ceramics was determined by the degree of phase transformation T-ZrO2 → M-ZrO2 under experimental conditions. Porous microstructures were formed in the samples, which differ in the size distribution of both grains and pores. A characteristic feature is the presence of various amounts of fine-grained fragments with a regular microstructure and the formation of both rounded and elongated grains.The phase transformation T-ZrO2 → M-ZrO2 leads to an increase of the samples porosity. This, in turn, contributes to the intensification of the ceramics aging. After 14 h the phase transformation T-ZrO2 → M-ZrO2 was found in four samples. In the sample 97ZrO2—3Y2O3, 46% of M-ZrO2 was formed; in the 95ZrO2—3Y2O3—2CeO2 sample, 48% of M-ZrO2 was formed; in the 92,5ZrO2—2,5Y2O3—5CeO2 sample, 39% of M-ZrO2 was formed. In the 90ZrO2—2Y2O3–8CeO2 sample ≈1% of M-ZrO2 appeared, and in the 88ZrO2—12CeO2 sample M-ZrO2 was not identified. Formation features of the solid solution during the doping of zirconia with yttrium oxide and cerium oxide, the amount of cerium oxide in a ZrO2-based solid solution, the phase transformation F-ZrO2 → T-ZrO2 during the sintering and the formation of a homogeneous microstructure contribute to increasing the low-temperature phase stability of samples both 90ZrO2—2Y2O3—8CeO2 and 88ZrO2—12CeO2 composition. During the microstructural design of ceramics in the ZrO2—Y2O3—CeO2 system with increased low-temperature phase stability, it is necessary to establish such a ratio of Y2O3 and CeO2 in the solid solution based on ZrO2 that would provide the necessary strength behavior according to the ceramics use. Keywords: ZrO2—Y2O3—CeO2 system, ZrO2-based solid solution, M-ZrO2 phase, aging, low-temperature phase stability.","PeriodicalId":509971,"journal":{"name":"Uspihi materialoznavstva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139189025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.15407/materials2023.07.003
A. O. Gorpenko, O. I. Semenets
The restoration of the surface of damaged parts made of high-strength titanium alloys by the method of restorative surfacing with the use of filler wires is a quite reasonable and promising technique since its aims is to restore a partially damaged surface of parts while preserving their strength properties. However, this technique requires a significant number of static, fatigue and corrosion tests to be followed by suitable processing of the obtained results to correct or improve even the welding technology. The main purpose of the research was to study the fatigue behavior of samples with a restored surface by the method of metal surfacing. Fatigue tests were carried out on VT-22 alloy samples, the surface of which was restored by surfacing using SP-15 and VT-22 filler wires. Fractography revealed the presence of several welding defects (pores mainly) located both in the zone of the deposited metal and on its borders. These conclusions summarize the obtained research results and provide important information about the correlation between welding defects, fatigue strength, and the properties of the VT-22 alloy. The results showed that the presence of these defects is primarily related to the initiation of fatigue cracks. The size and shape of defects, as well as their location relative to the deposited layer, also affected the reduction of fatigue properties. Correcting the surfacing conditions may significantly reduce the critical size of defects and, as a result, significantly increase the residual life of restored parts. Keywords: high-strength titanium alloy VT-22, welding pores, segregation of defects, zone of thermal influence, cyclic loading.
{"title":"The influence of welding defects on the fracture mechanism of samples made of the VT-22 alloy, with the use of restorative surfacing with filler wires","authors":"A. O. Gorpenko, O. I. Semenets","doi":"10.15407/materials2023.07.003","DOIUrl":"https://doi.org/10.15407/materials2023.07.003","url":null,"abstract":"The restoration of the surface of damaged parts made of high-strength titanium alloys by the method of restorative surfacing with the use of filler wires is a quite reasonable and promising technique since its aims is to restore a partially damaged surface of parts while preserving their strength properties. However, this technique requires a significant number of static, fatigue and corrosion tests to be followed by suitable processing of the obtained results to correct or improve even the welding technology. The main purpose of the research was to study the fatigue behavior of samples with a restored surface by the method of metal surfacing. Fatigue tests were carried out on VT-22 alloy samples, the surface of which was restored by surfacing using SP-15 and VT-22 filler wires. Fractography revealed the presence of several welding defects (pores mainly) located both in the zone of the deposited metal and on its borders. These conclusions summarize the obtained research results and provide important information about the correlation between welding defects, fatigue strength, and the properties of the VT-22 alloy. The results showed that the presence of these defects is primarily related to the initiation of fatigue cracks. The size and shape of defects, as well as their location relative to the deposited layer, also affected the reduction of fatigue properties. Correcting the surfacing conditions may significantly reduce the critical size of defects and, as a result, significantly increase the residual life of restored parts. Keywords: high-strength titanium alloy VT-22, welding pores, segregation of defects, zone of thermal influence, cyclic loading.","PeriodicalId":509971,"journal":{"name":"Uspihi materialoznavstva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139191943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.15407/materials2023.07.009
N. O. Krasovska, V. P. Krasovskyy
Wetting of infrared-transparent materials — selenide and sulfide zinc, germanium, and silicon by metal melts in a vacuum in a wide temperature range was studied by the sessile drop method using the method of capillary purification of the drop melt during the experiment. Pure metals In, Sn, Pb, Al, Fe, Ni, binary Al—Si, Ge—Si, In—Cu and multicomponent In—Sn—Cu—Ti alloys were used. When zinc chalcogenides are wetted with In—Sn—Cu—Ti melts, zinc selenide is wetted better than zinc sulfide. This is due to the lower thermodynamic stability of selenide. In systems where copper is present in melts, wetting is affected not only by the interaction of selenium or sulfur with titanium, but also by the interaction of copper and zinc (in the copper-zinc system, solid solutions of copper and zinc are formed and copper dissolves in solid zinc). This conclusion also confirms the wetting of the substrate by the In—Cu melt. The values of the contact angle at 650 C are equal to 32, which is less than for the In—Sn—Ti melt at the same temperature. It can be said that for such a system, the interaction of zinc with copper is very important, which is not inferior to the wetting effect of the interaction of chalcogens with titanium. The wetting of single crystals of germanium and silicon by metal melts improves with increasing temperature. Iron and nickel wet silicon (contact angles close to zero) at temperatures lower than their melting point. Contact melting also occurs when silicon substrates are wetted with aluminum melts (the eutectic in the Al—Si system has a temperature of 577 °C). Germanium is better wetted by tin than by indium and lead. Technological processes of soldering infrared transparent materials with metals were developed and soldered joints were obtained. Keywords: infrared transparent materials, polycrystalline zinc selenide and sulfide, single crystals of germanium and silicon, wetting, soldering.
{"title":"Study of the interaction of infrared transparent ZnSe, ZnS, Si, Ge materials with metal melts","authors":"N. O. Krasovska, V. P. Krasovskyy","doi":"10.15407/materials2023.07.009","DOIUrl":"https://doi.org/10.15407/materials2023.07.009","url":null,"abstract":"Wetting of infrared-transparent materials — selenide and sulfide zinc, germanium, and silicon by metal melts in a vacuum in a wide temperature range was studied by the sessile drop method using the method of capillary purification of the drop melt during the experiment. Pure metals In, Sn, Pb, Al, Fe, Ni, binary Al—Si, Ge—Si, In—Cu and multicomponent In—Sn—Cu—Ti alloys were used. When zinc chalcogenides are wetted with In—Sn—Cu—Ti melts, zinc selenide is wetted better than zinc sulfide. This is due to the lower thermodynamic stability of selenide. In systems where copper is present in melts, wetting is affected not only by the interaction of selenium or sulfur with titanium, but also by the interaction of copper and zinc (in the copper-zinc system, solid solutions of copper and zinc are formed and copper dissolves in solid zinc). This conclusion also confirms the wetting of the substrate by the In—Cu melt. The values of the contact angle at 650 C are equal to 32, which is less than for the In—Sn—Ti melt at the same temperature. It can be said that for such a system, the interaction of zinc with copper is very important, which is not inferior to the wetting effect of the interaction of chalcogens with titanium. The wetting of single crystals of germanium and silicon by metal melts improves with increasing temperature. Iron and nickel wet silicon (contact angles close to zero) at temperatures lower than their melting point. Contact melting also occurs when silicon substrates are wetted with aluminum melts (the eutectic in the Al—Si system has a temperature of 577 °C). Germanium is better wetted by tin than by indium and lead. Technological processes of soldering infrared transparent materials with metals were developed and soldered joints were obtained. Keywords: infrared transparent materials, polycrystalline zinc selenide and sulfide, single crystals of germanium and silicon, wetting, soldering.","PeriodicalId":509971,"journal":{"name":"Uspihi materialoznavstva","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139194889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：