Pub Date : 1900-01-01DOI: 10.30791/0015-3214-2022-2-35-54
Е. Lantsev, N. Malekhonova, V. Chuvil’deev, А. Nokhrin, Y. Tsvetkov, Yu. V. Blagoveshchenskiy, M. Boldin, N. Isaeva, P. Andreev, K. Smetanina
The features of high-speed spark plasma sintering (SPS) of plasma-chemical nanopowders WC – (0.3, 0.6, 1) wt. % Co with the addition of 0.3 and 0.5 wt. % graphite were studied. The structural features of the ultralow-cobalt hard alloys with graphite addition during SPS are due to the simultaneous influence of an increased concentration of oxygen adsorbed on the surface of plasma-chemical WC – Co nanoparticles during mixing with graphite, and the effect of graphite, which leads to a decrease in activation energy of sintering due to a decrease in the intensity of formation of η-phase particles in “oxidized” WC – Co nanopowders, as well as the formation of a fairly uniform fine-grained structure. Samples of fine-grained ultralow-cobalt hard alloys with increased hardness and fracture toughness were obtained (for a WC – 0.6 wt. % Co – 0.3 wt. % C hard alloy with an average grain size of ~ (1 – 1.5) mm, the hardness is Hv = 20.2 – 20.5 GPa with a minimum crack resistance coefficient KIC = 9.2 – 10.4 MPa·m1/2).
{"title":"Study of high-speed sintering of fine-grained hard alloys based on tungsten carbide with ultralow cobalt content. III. Effect of C content on sintering kinetics of the nanopowders","authors":"Е. Lantsev, N. Malekhonova, V. Chuvil’deev, А. Nokhrin, Y. Tsvetkov, Yu. V. Blagoveshchenskiy, M. Boldin, N. Isaeva, P. Andreev, K. Smetanina","doi":"10.30791/0015-3214-2022-2-35-54","DOIUrl":"https://doi.org/10.30791/0015-3214-2022-2-35-54","url":null,"abstract":"The features of high-speed spark plasma sintering (SPS) of plasma-chemical nanopowders WC – (0.3, 0.6, 1) wt. % Co with the addition of 0.3 and 0.5 wt. % graphite were studied. The structural features of the ultralow-cobalt hard alloys with graphite addition during SPS are due to the simultaneous influence of an increased concentration of oxygen adsorbed on the surface of plasma-chemical WC – Co nanoparticles during mixing with graphite, and the effect of graphite, which leads to a decrease in activation energy of sintering due to a decrease in the intensity of formation of η-phase particles in “oxidized” WC – Co nanopowders, as well as the formation of a fairly uniform fine-grained structure. Samples of fine-grained ultralow-cobalt hard alloys with increased hardness and fracture toughness were obtained (for a WC – 0.6 wt. % Co – 0.3 wt. % C hard alloy with an average grain size of ~ (1 – 1.5) mm, the hardness is Hv = 20.2 – 20.5 GPa with a minimum crack resistance coefficient KIC = 9.2 – 10.4 MPa·m1/2).","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"126 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128062369","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 : 1900-01-01DOI: 10.30791/0015-3214-2022-6-54-69
A. A. Dorofeev, A. Samokhin, A. Fadeev, N. Alekseev, M. Sinayskiy, I. S. Litvinova, I. Zavertyaev
A method for obtaining nanopowder microgranules of the W – Ni – Fe system (composition of the VNJ-90) of a micron size range by spray drying of a suspension based on composite nanoparticles obtained by plasma chemical synthesis is considered. The parameters of operation of the Buchi Mini Spray Dryer B-290 spray drying laboratory unit with an ultrasonic nozzle have been experimentally determined, providing for the production of nanopowder microgranules of VNJ-90 with an output of the target fraction of 25 – 63 µm at the level of 65 %. The dependence of the size and morphology of the obtained granules on the choice of the dispersion medium, the concentration of the dispersed phase and the organic binder in the suspension is established. The effect of the suspension flow rate during spray drying on the yield of granules of a fraction of 25 – 63 µm was evaluated. The test of the manufactured experimental sample of nanopowder microgranules in the process of plasma spheroidization was carried out.
研究了用等离子体化学合成的复合纳米颗粒为基础，通过喷雾干燥得到微米级W - Ni - Fe体系(VNJ-90的组成)的纳米粉末微颗粒的方法。实验确定了布吉微型喷雾干燥机B-290超声喷嘴喷雾干燥实验室装置的操作参数，为生产VNJ-90纳米粉末微颗粒提供了条件，目标分数为25 ~ 63µm，输出水平为65%。建立了分散介质的选择、分散相的浓度和悬浮液中有机结合剂的选择对所得颗粒大小和形貌的影响。考察了喷雾干燥过程中悬浮流速对25 ~ 63µm颗粒得率的影响。对制备的纳米粉末微颗粒实验样品在等离子体球化过程中进行了测试。
{"title":"Investigation of the granulation process of the W – Ni – Fe system nanopowder by spray drying","authors":"A. A. Dorofeev, A. Samokhin, A. Fadeev, N. Alekseev, M. Sinayskiy, I. S. Litvinova, I. Zavertyaev","doi":"10.30791/0015-3214-2022-6-54-69","DOIUrl":"https://doi.org/10.30791/0015-3214-2022-6-54-69","url":null,"abstract":"A method for obtaining nanopowder microgranules of the W – Ni – Fe system (composition of the VNJ-90) of a micron size range by spray drying of a suspension based on composite nanoparticles obtained by plasma chemical synthesis is considered. The parameters of operation of the Buchi Mini Spray Dryer B-290 spray drying laboratory unit with an ultrasonic nozzle have been experimentally determined, providing for the production of nanopowder microgranules of VNJ-90 with an output of the target fraction of 25 – 63 µm at the level of 65 %. The dependence of the size and morphology of the obtained granules on the choice of the dispersion medium, the concentration of the dispersed phase and the organic binder in the suspension is established. The effect of the suspension flow rate during spray drying on the yield of granules of a fraction of 25 – 63 µm was evaluated. The test of the manufactured experimental sample of nanopowder microgranules in the process of plasma spheroidization was carried out.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"122 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128148542","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 : 1900-01-01DOI: 10.30791/0015-3214-2021-4-31-41
L. Kuksenova, D. Kozlov, M. Alekseeva
Improving the reliability, durability and safety of operation of heavily loaded friction units is an urgent problem in physics, chemistry and surface mechanics. The tribotechnical characteristics of coatings made of bronzes BrAZhMts10-3-1.5 and BrMtsF3-6, applied by electrospark alloying on bushings made of structural steel 30KhGSN2A for operation under conditions of high contact pressure under friction without lubrication, have been investigated. Modes of coating deposition from the standpoint of tribology (the value of the electric discharge current in a pulse, the value of the longitudinal electrode feed per one rotation of the part, the rotation speed of the workpiece, the number of passes during processing, finishing of the coating) have been developed. It was found that when applying bronze BrMtsF3-6 to obtain a high-quality coating, the process must be performed in a protective atmosphere of argon to prevent phosphorus burnout. The tribotechnical efficiency of coatings when working under dry friction conditions is shown. For the steady-state wear mode, the friction coefficient is 0.10 – 0.13 at a pressure of 200 – 250 MPa, the wear resistance of coated steel is doubled. Steel with a bronze coating BrAZhMts10-3-1.5 has a higher bearing capacity, with BrMtsF3-6 coating — a higher antifriction. The ways of increasing the service life of steel-coated steel friction pair are analyzed.
{"title":"Study of operational properties of steel friction pairs with antifriction coating from copper alloys produced by electric spark alloying","authors":"L. Kuksenova, D. Kozlov, M. Alekseeva","doi":"10.30791/0015-3214-2021-4-31-41","DOIUrl":"https://doi.org/10.30791/0015-3214-2021-4-31-41","url":null,"abstract":"Improving the reliability, durability and safety of operation of heavily loaded friction units is an urgent problem in physics, chemistry and surface mechanics. The tribotechnical characteristics of coatings made of bronzes BrAZhMts10-3-1.5 and BrMtsF3-6, applied by electrospark alloying on bushings made of structural steel 30KhGSN2A for operation under conditions of high contact pressure under friction without lubrication, have been investigated. Modes of coating deposition from the standpoint of tribology (the value of the electric discharge current in a pulse, the value of the longitudinal electrode feed per one rotation of the part, the rotation speed of the workpiece, the number of passes during processing, finishing of the coating) have been developed. It was found that when applying bronze BrMtsF3-6 to obtain a high-quality coating, the process must be performed in a protective atmosphere of argon to prevent phosphorus burnout. The tribotechnical efficiency of coatings when working under dry friction conditions is shown. For the steady-state wear mode, the friction coefficient is 0.10 – 0.13 at a pressure of 200 – 250 MPa, the wear resistance of coated steel is doubled. Steel with a bronze coating BrAZhMts10-3-1.5 has a higher bearing capacity, with BrMtsF3-6 coating — a higher antifriction. The ways of increasing the service life of steel-coated steel friction pair are analyzed.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125031931","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 : 1900-01-01DOI: 10.30791/0015-3214-2022-5-21-30
E. O. Nasakina, A. D. Popova, M. Kaplan, A. Mikhailova, M. Sudarchikova, D. A. Novikova, K. V. Sergienko, A. Kolmakov, M. A. Sevost’yanov
Nano- and microdimensional tantalum surface layers were created on wire and flat NiTi substrates by magnetron sputtering. The samples structure and composition were determined using SEM and Auger spectroscopy. As the sputtering time increases, the thickness of the surface layer increases non-linearly, which leads to a change in the radiopacity of the material relative to the substrate. Based on the calculations of the coefficient of linear attenuation of X-ray radiation, it is shown that a layered composite in the form of a plate with a surface layer on only one side can be conditionally represented as a multicomponent monolith, but with a rounded sample section, a continuous surface layer surrounding it from all sides has a greater effect on radiopacity.
{"title":"Study of the influence of surface layer parameters on the level of their X-ray contrast","authors":"E. O. Nasakina, A. D. Popova, M. Kaplan, A. Mikhailova, M. Sudarchikova, D. A. Novikova, K. V. Sergienko, A. Kolmakov, M. A. Sevost’yanov","doi":"10.30791/0015-3214-2022-5-21-30","DOIUrl":"https://doi.org/10.30791/0015-3214-2022-5-21-30","url":null,"abstract":"Nano- and microdimensional tantalum surface layers were created on wire and flat NiTi substrates by magnetron sputtering. The samples structure and composition were determined using SEM and Auger spectroscopy. As the sputtering time increases, the thickness of the surface layer increases non-linearly, which leads to a change in the radiopacity of the material relative to the substrate. Based on the calculations of the coefficient of linear attenuation of X-ray radiation, it is shown that a layered composite in the form of a plate with a surface layer on only one side can be conditionally represented as a multicomponent monolith, but with a rounded sample section, a continuous surface layer surrounding it from all sides has a greater effect on radiopacity.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"131 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121609063","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 : 1900-01-01DOI: 10.30791/0015-3214-2022-6-11-16
S. V. Simakov, N. Vinogradova, A. Ashmarin, A. B. Mikhajlova, O. N. Nikitushkina, E. E. Starostin, V. I. Tovtin
Effect of plastic deformation, heat treatment, and electron irradiation on the structural-phase state of Cu – 40 at. % Pd is studied. X-ray phase analysis of initial samples, samples obtained by rolling up to 0.2 mm, samples annealed after rolling in an argon atmosphere at 950 °C for 1 h, and samples irradiated by high-energy electron in air at temperature of 300 °C was carried out. A change in the phase composition of the samples after rolling was found: ~ 6 % of the ordered β-phase with bcc structure was formed, which disappears after annealing. As a result of irradiation, a layer of copper oxide CuO formed on the surface of the alloy, which under normal thermal conditions is formed at a temperatures of 400 – 500 °C, and the reflections of the ordered β-phase also disappeared in the near-surface layer. The elemental composition of the alloy changed in depth from the irradiated metal surface. Phases with a low degree of long-range order and an increased content of palladium were formed. The presence of these phases is due mainly to the selective oxidation of copper.
{"title":"Effect of plastic deformation, heat treatment and electron irradiation on structural-phase state of Cu – 40 аt. % Pd alloy","authors":"S. V. Simakov, N. Vinogradova, A. Ashmarin, A. B. Mikhajlova, O. N. Nikitushkina, E. E. Starostin, V. I. Tovtin","doi":"10.30791/0015-3214-2022-6-11-16","DOIUrl":"https://doi.org/10.30791/0015-3214-2022-6-11-16","url":null,"abstract":"Effect of plastic deformation, heat treatment, and electron irradiation on the structural-phase state of Cu – 40 at. % Pd is studied. X-ray phase analysis of initial samples, samples obtained by rolling up to 0.2 mm, samples annealed after rolling in an argon atmosphere at 950 °C for 1 h, and samples irradiated by high-energy electron in air at temperature of 300 °C was carried out. A change in the phase composition of the samples after rolling was found: ~ 6 % of the ordered β-phase with bcc structure was formed, which disappears after annealing. As a result of irradiation, a layer of copper oxide CuO formed on the surface of the alloy, which under normal thermal conditions is formed at a temperatures of 400 – 500 °C, and the reflections of the ordered β-phase also disappeared in the near-surface layer. The elemental composition of the alloy changed in depth from the irradiated metal surface. Phases with a low degree of long-range order and an increased content of palladium were formed. The presence of these phases is due mainly to the selective oxidation of copper.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121107947","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 : 1900-01-01DOI: 10.30791/0015-3214-2022-2-55-64
О. V. Bakina, Е. А. Glazkova, Е. А. Vornakova, V. Zhou, K. Suliz
In present work, the possibility of obtaining ZnFe2O4/ZnO nanoparticles by electric explosion of zinc and iron wires in an oxygen-containing atmosphere is shown. Based on the obtained nanoparticles and polymethyl methacrylate, ZnFe2O4/ZnO/PMMA composite was obtained, containing from 0.5 to 10 wt. % of nanoparticles. The composite film suppressed the viability of E. coli bacteria with an efficiency of 99.99 %, which is due to the generation of reactive oxygen species. The synthesized composite material with high antibacterial activity is promising for the production of antimicrobial materials for medicine for a long time.
{"title":"Preparation of ZnFe2O4/ZnO/PMMA composition with antibacterial properties and low toxicity","authors":"О. V. Bakina, Е. А. Glazkova, Е. А. Vornakova, V. Zhou, K. Suliz","doi":"10.30791/0015-3214-2022-2-55-64","DOIUrl":"https://doi.org/10.30791/0015-3214-2022-2-55-64","url":null,"abstract":"In present work, the possibility of obtaining ZnFe2O4/ZnO nanoparticles by electric explosion of zinc and iron wires in an oxygen-containing atmosphere is shown. Based on the obtained nanoparticles and polymethyl methacrylate, ZnFe2O4/ZnO/PMMA composite was obtained, containing from 0.5 to 10 wt. % of nanoparticles. The composite film suppressed the viability of E. coli bacteria with an efficiency of 99.99 %, which is due to the generation of reactive oxygen species. The synthesized composite material with high antibacterial activity is promising for the production of antimicrobial materials for medicine for a long time.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115450256","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 : 1900-01-01DOI: 10.30791/0015-3214-2021-2-80-85
Z. I. Iskenderova
In this work, a comparative study of the kinetics of changes in the pH indicator, the formation of H2O2 and CO2 depending on the absorbed dose at the radiolysis of TCB containing transformer oil in the presence and without nano-γ-Al2O3 under the action of γ radiation was carried out. During radiolysis of both systems (TСB + transformer oil and TСB + transformer oil + 0.1 g of nano-γ-Al2O3), the radiation-chemical yield of CO2 decreases with an increase in the initial concentration of TCB, although at the presence of nano-particles, the values of the radiation-chemical riels of CO2 become less. Unlike CO2, the radiation-chemical yields of H2O2 increase with an increase in the initial concentration of TCB, but their values are less in the presence of nano-γ-Al2O3. The results obtained are explained by the reactions of active particles, radiolysis of the main components of transformer oil, such as hydrogen atoms and hydrocarbon radicals with TCB and dissolved oxygen molecules. In addition, there is a transfer of electronic excitation energy from alkane and cycloalkane molecules to aromatic hydrocarbon molecules. The effect of nano-γ-Al2O3 on the radiolysis of the mixture is discussed on the basis of the reaction of electron and hole centers with the molecules of the components of the irradiated mixture.
{"title":"Radiolysis of transformer oil in presence of trichlorbenzen and nano-γ-Al2O3","authors":"Z. I. Iskenderova","doi":"10.30791/0015-3214-2021-2-80-85","DOIUrl":"https://doi.org/10.30791/0015-3214-2021-2-80-85","url":null,"abstract":"In this work, a comparative study of the kinetics of changes in the pH indicator, the formation of H2O2 and CO2 depending on the absorbed dose at the radiolysis of TCB containing transformer oil in the presence and without nano-γ-Al2O3 under the action of γ radiation was carried out. During radiolysis of both systems (TСB + transformer oil and TСB + transformer oil + 0.1 g of nano-γ-Al2O3), the radiation-chemical yield of CO2 decreases with an increase in the initial concentration of TCB, although at the presence of nano-particles, the values of the radiation-chemical riels of CO2 become less. Unlike CO2, the radiation-chemical yields of H2O2 increase with an increase in the initial concentration of TCB, but their values are less in the presence of nano-γ-Al2O3. The results obtained are explained by the reactions of active particles, radiolysis of the main components of transformer oil, such as hydrogen atoms and hydrocarbon radicals with TCB and dissolved oxygen molecules. In addition, there is a transfer of electronic excitation energy from alkane and cycloalkane molecules to aromatic hydrocarbon molecules. The effect of nano-γ-Al2O3 on the radiolysis of the mixture is discussed on the basis of the reaction of electron and hole centers with the molecules of the components of the irradiated mixture.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124031420","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 : 1900-01-01DOI: 10.30791/0015-3214-2019-5-21-35
E. Voronina, L. Novikov, Y. Mankelevich
{"title":"Simulation of plasma particle impacts on 2D materials","authors":"E. Voronina, L. Novikov, Y. Mankelevich","doi":"10.30791/0015-3214-2019-5-21-35","DOIUrl":"https://doi.org/10.30791/0015-3214-2019-5-21-35","url":null,"abstract":"","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130284816","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 : 1900-01-01DOI: 10.30791/0015-3214-2021-4-25-30
O. Berdnik, P. Y. Kikin, V. Perevezentsev, E. Razov, E. Rusin, I. Tsareva
The regularities of changes in the structure and phase composition of the thermal protective aluminide-nickel coating (Ni — 45 %; Al — 14 %; Co — 22 %; Cr — 18.9 %; Fe — 0.15 %; Nb — 0.14 %; Y — 0.09 %; Ca — 0.06 %; Mn — 0.01 %; C — 0.15 %; Si — 0.15 %; S — 0.006 %) after exposure to short-term pulsed heat fluxes of various power, created by the radiation of a pulse-periodic laser LRS-150A with a radiation wavelength λ = 1.06 µm and a pulse duration τ = 12·10–3 s. The radiation energy was E = 5, 10, and 15 J. Microstructural analysis and the elemental composition of the resulting coating were carried out as well as analysis of the phase composition. X-ray microanalysis of the coating was also carried out. In the initial state and after irradiation of the coating with a heat flux of power P = 7·103 W/cm2, light microregions are observed in the micrographs of the surface. These regions do not have clearly defined external boundaries and consist of the NiAl phase and a small amount of the Ni3Al phase with the presence of inclusions of particles containing a solid solution of Ni – Co – Cr. After irradiation of the coating with heat fluxes of higher power (P = 1.7·104 W/cm2 and P = 2.2·104 W/cm2), large convex formations appeared on its surface, consisting mainly of Ni3Al and NiAl phases. On micrographs of the surface, they appear as white areas with well-defined outer boundaries. The content of the Ni3Al phase in them in comparison with the initial state increased, and the content of the NiAl phase decreased, while the particles of inclusions of Ni, Co, and Cr disappeared. It can be assumed that an increase in the Ni3Al content is associated with the dissolution of particles of a solid solution of Ni – Co and Cr in the melt and the subsequent diffusion of nickel into the NiAl phase. When exposed to a heat flux of power P = 2.2·104 W/cm2, microcracks appear on the areas of the coating surface covered with aluminum oxide.
{"title":"Changes in the structure of a thermal protective aluminum-nickel coating under the influence of a single thermal laser pulse","authors":"O. Berdnik, P. Y. Kikin, V. Perevezentsev, E. Razov, E. Rusin, I. Tsareva","doi":"10.30791/0015-3214-2021-4-25-30","DOIUrl":"https://doi.org/10.30791/0015-3214-2021-4-25-30","url":null,"abstract":"The regularities of changes in the structure and phase composition of the thermal protective aluminide-nickel coating (Ni — 45 %; Al — 14 %; Co — 22 %; Cr — 18.9 %; Fe — 0.15 %; Nb — 0.14 %; Y — 0.09 %; Ca — 0.06 %; Mn — 0.01 %; C — 0.15 %; Si — 0.15 %; S — 0.006 %) after exposure to short-term pulsed heat fluxes of various power, created by the radiation of a pulse-periodic laser LRS-150A with a radiation wavelength λ = 1.06 µm and a pulse duration τ = 12·10–3 s. The radiation energy was E = 5, 10, and 15 J. Microstructural analysis and the elemental composition of the resulting coating were carried out as well as analysis of the phase composition. X-ray microanalysis of the coating was also carried out. In the initial state and after irradiation of the coating with a heat flux of power P = 7·103 W/cm2, light microregions are observed in the micrographs of the surface. These regions do not have clearly defined external boundaries and consist of the NiAl phase and a small amount of the Ni3Al phase with the presence of inclusions of particles containing a solid solution of Ni – Co – Cr. After irradiation of the coating with heat fluxes of higher power (P = 1.7·104 W/cm2 and P = 2.2·104 W/cm2), large convex formations appeared on its surface, consisting mainly of Ni3Al and NiAl phases. On micrographs of the surface, they appear as white areas with well-defined outer boundaries. The content of the Ni3Al phase in them in comparison with the initial state increased, and the content of the NiAl phase decreased, while the particles of inclusions of Ni, Co, and Cr disappeared. It can be assumed that an increase in the Ni3Al content is associated with the dissolution of particles of a solid solution of Ni – Co and Cr in the melt and the subsequent diffusion of nickel into the NiAl phase. When exposed to a heat flux of power P = 2.2·104 W/cm2, microcracks appear on the areas of the coating surface covered with aluminum oxide.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130306073","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 : 1900-01-01DOI: 10.30791/0015-3214-2021-3-24-29
Y. Kashlev, S. A. Maslyaev
A vacancy in a one-dimensional lattice is considered as a vacant site in a one-dimensional chain of atoms. The energy model of this system is a double potential well with two levels. Based on the relations of nonequilibrium statistical mechanics, including the Kubo formula for the transport coefficient, the frequency of vacancy jumps is calculated. In this case, two factors of the system perturbation are taken into account: lattice deformation associated with the formation of an empty site, and phonon scattering by mass fluctuations in the chain. An analysis of two high-temperature jumps is given. First, the classical limit of vacancy motion under weak coupling conditions is considered for small values of the gradient of the interaction potential of the defect with the chain. In the classical case, the transition of an atom adjacent to a vacancy occurs through a quasy-stationary excited state. Secondly, a jump under tight binding conditions, when the motion of a neighboring atom occurs through a quasistationary state of finite width, and therefore having a finite lifetime.
{"title":"Non-coherent diffusion of a vacancy in a one-dimensional lattice in the quasiclassical approximation","authors":"Y. Kashlev, S. A. Maslyaev","doi":"10.30791/0015-3214-2021-3-24-29","DOIUrl":"https://doi.org/10.30791/0015-3214-2021-3-24-29","url":null,"abstract":"A vacancy in a one-dimensional lattice is considered as a vacant site in a one-dimensional chain of atoms. The energy model of this system is a double potential well with two levels. Based on the relations of nonequilibrium statistical mechanics, including the Kubo formula for the transport coefficient, the frequency of vacancy jumps is calculated. In this case, two factors of the system perturbation are taken into account: lattice deformation associated with the formation of an empty site, and phonon scattering by mass fluctuations in the chain. An analysis of two high-temperature jumps is given. First, the classical limit of vacancy motion under weak coupling conditions is considered for small values of the gradient of the interaction potential of the defect with the chain. In the classical case, the transition of an atom adjacent to a vacancy occurs through a quasy-stationary excited state. Secondly, a jump under tight binding conditions, when the motion of a neighboring atom occurs through a quasistationary state of finite width, and therefore having a finite lifetime.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"2015 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127781975","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：