Pub Date : 2024-03-22DOI: 10.26896/1028-6861-2024-90-3-78-88
S. M. Shebanov
The main goal of the work is to obtain additional information about the experimentally obtained sample with a previously known theoretical distribution, the point estimates of the parameters of which are considered known. At the same time, the laws of distribution of these parameters remain unknown, whereas they could provide a researcher with additional information about both the material and technological processes. Hence, it is necessary to obtain an additional number of samples, which is not always possible experimentally. Here we used data on the service life of cutters (GOST 11.011–83 «Rules for determining estimates and confidence limits for gamma distribution parameters») as an experimental sample. The experimental sample contains the results of 50 measurements. The mean was 57.88 hours CI [50.74:65.01]. The confidence probability is taken to be 0.95. Bootstrap was used as a way to obtain additional samples. The universal mathematical package MATLAB is used in the study. Bootstrap allows generation of a large number of samples that require certain selection rules to be applied to them. The first obvious requirement is the significance of the correlation coefficient of the generated sample with the original one. Even at this stage, the bootstrap showed certain limitations in performing the task set in the study. For 1000 samples generated by the standard bootstrap routine, the mean for the population of all mean bootstrap samples was 57.80 hours, and the confidence interval was [50.59:58.08]. The result is good. Though the nonparametric hypothesis regarding an agreement between the bootstrap samples for the gamma distribution and the parameters characteristic of the original experimentally obtained sample was not rejected, the statistically significant correlation coefficient was observed only for 29 bootstrap samples. As a result of meeting these obvious requirements, less than 3% of the generated bootstrap samples remained for further consideration. This fact requires the introduction of additional conditions when using the bootstrap to obtain samples that are close to the original experimental sample, which can be rather specific. To determine the parameters of the gamma distribution for bootstrap samples, the method of moments and the one-step method were used.
{"title":"Studying the estimates of gamma distribution parameters","authors":"S. M. Shebanov","doi":"10.26896/1028-6861-2024-90-3-78-88","DOIUrl":"https://doi.org/10.26896/1028-6861-2024-90-3-78-88","url":null,"abstract":"The main goal of the work is to obtain additional information about the experimentally obtained sample with a previously known theoretical distribution, the point estimates of the parameters of which are considered known. At the same time, the laws of distribution of these parameters remain unknown, whereas they could provide a researcher with additional information about both the material and technological processes. Hence, it is necessary to obtain an additional number of samples, which is not always possible experimentally. Here we used data on the service life of cutters (GOST 11.011–83 «Rules for determining estimates and confidence limits for gamma distribution parameters») as an experimental sample. The experimental sample contains the results of 50 measurements. The mean was 57.88 hours CI [50.74:65.01]. The confidence probability is taken to be 0.95. Bootstrap was used as a way to obtain additional samples. The universal mathematical package MATLAB is used in the study. Bootstrap allows generation of a large number of samples that require certain selection rules to be applied to them. The first obvious requirement is the significance of the correlation coefficient of the generated sample with the original one. Even at this stage, the bootstrap showed certain limitations in performing the task set in the study. For 1000 samples generated by the standard bootstrap routine, the mean for the population of all mean bootstrap samples was 57.80 hours, and the confidence interval was [50.59:58.08]. The result is good. Though the nonparametric hypothesis regarding an agreement between the bootstrap samples for the gamma distribution and the parameters characteristic of the original experimentally obtained sample was not rejected, the statistically significant correlation coefficient was observed only for 29 bootstrap samples. As a result of meeting these obvious requirements, less than 3% of the generated bootstrap samples remained for further consideration. This fact requires the introduction of additional conditions when using the bootstrap to obtain samples that are close to the original experimental sample, which can be rather specific. To determine the parameters of the gamma distribution for bootstrap samples, the method of moments and the one-step method were used.","PeriodicalId":504498,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":" 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140218271","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 : 2024-03-22DOI: 10.26896/1028-6861-2024-90-3-52-61
S. Bisong, V. V. Lepov, A. R. Etinge
The mechanical behavior of local wood species (Bilinga) in the south west region in Cameroon during rainy and dry seasons and the mechanical behavior of wooden beam under bend loading are studied. The three points flexural tests were used to determine the mechanical properties of the wood under study. ANSYS 2020 R1 finite element (FE) software is used for numerical simulations at a macroscopic level using one of the newer technologies called Smart crack growth, which was introduced in the 2019 version. The geometry was modeled in SolidWorks with an initial crack length of 4 and 8 mm introduced in each sample and then imported to ANSYS workbench for further analysis with ANSYS which has all the tools to perform linear fracture. The stress intensity factor (SIF) determines the fracture toughness of a material which is subjected to linear-elastic fracture mechanics (LEFM) where a variable of the critical stress intensify is denoted as KIc. The fatigue crack growth was modeled using Paris’ law. The crack growth was simulated based on Mode I crack specimen with an initial crack length of 4 and 8 mm, respectively. The stochastic multiscale modeling of crack growth on meso- and microscale is used to compare the crack growth rate in the approach of a heterogeneous material and taking into account the microstructure and fracture mechanism of the Bilinga wood. The results of stochastic modeling of the crack growth in the array of cracks and pores of a characteristic size shows that the simulation is close to FE-modeling results. Therefore, the stochastic simulation of the crack growth in wood at meso- and microscale shows the lower local stress intensity factors and slower crack growth due to the existence of the scale-time hierarchy. The crack growth rate vcr at a macroscale ranges within 0.845 – 0.9 × 10–3 m/sec which corresponds to the macroscopic value of the fracture toughness KIc.
{"title":"Study of the mechanical behavior and multiscale simulation of the crack propagation in a bilinga wooden beam","authors":"S. Bisong, V. V. Lepov, A. R. Etinge","doi":"10.26896/1028-6861-2024-90-3-52-61","DOIUrl":"https://doi.org/10.26896/1028-6861-2024-90-3-52-61","url":null,"abstract":"The mechanical behavior of local wood species (Bilinga) in the south west region in Cameroon during rainy and dry seasons and the mechanical behavior of wooden beam under bend loading are studied. The three points flexural tests were used to determine the mechanical properties of the wood under study. ANSYS 2020 R1 finite element (FE) software is used for numerical simulations at a macroscopic level using one of the newer technologies called Smart crack growth, which was introduced in the 2019 version. The geometry was modeled in SolidWorks with an initial crack length of 4 and 8 mm introduced in each sample and then imported to ANSYS workbench for further analysis with ANSYS which has all the tools to perform linear fracture. The stress intensity factor (SIF) determines the fracture toughness of a material which is subjected to linear-elastic fracture mechanics (LEFM) where a variable of the critical stress intensify is denoted as KIc. The fatigue crack growth was modeled using Paris’ law. The crack growth was simulated based on Mode I crack specimen with an initial crack length of 4 and 8 mm, respectively. The stochastic multiscale modeling of crack growth on meso- and microscale is used to compare the crack growth rate in the approach of a heterogeneous material and taking into account the microstructure and fracture mechanism of the Bilinga wood. The results of stochastic modeling of the crack growth in the array of cracks and pores of a characteristic size shows that the simulation is close to FE-modeling results. Therefore, the stochastic simulation of the crack growth in wood at meso- and microscale shows the lower local stress intensity factors and slower crack growth due to the existence of the scale-time hierarchy. The crack growth rate vcr at a macroscale ranges within 0.845 – 0.9 × 10–3 m/sec which corresponds to the macroscopic value of the fracture toughness KIc.","PeriodicalId":504498,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":" 39","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140214038","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 : 2024-03-22DOI: 10.26896/1028-6861-2024-90-3-62-69
R. Akhmetkhanov
The purpose of the article is to study the effect of the direction of reinforcement of a composite material relative to the cyclic load on the inhomogeneity of stress distribution by the thermal method of non-destructive testing using the thermoelastic effect. This method is widely used in all industries for the control of structural elements and in research work. The degree of stress inhomogeneity is used when choosing the safety factors necessary to ensure the safety of technical objects. In this study, the thermoelastic effect is used to show the possibility of estimating the local distribution of stresses using the temperature field of the test object, proceeding from the linear relation between the temperature of the elastic body and mechanical stresses. The results of studying composite laminates (fibrous filler (fiberglass) with an epoxy matrix) with different laying of fibers with respect to the direction of loading are presented. Four laminate samples were considered: single-layer [0] and [90], three-layer [0]3 and [90]3. Statistical data and estimates of the coefficients of variation, methods of clustering and averaging over the length of the laminates the values of the temperature distribution over the surface of the laminates. The numerical characteristics of the distribution of local temperatures are obtained. It is shown that a more uniform distribution occurs when reinforcing is directed along the direction of the material loading. The integral and local characteristics of the temperature distribution in the samples are compared. The differences in the local temperature distribution depending on the laminate thickness were noted visually for single-layer and three-layer samples. A more uniform distribution of the load is also observed in the direction of reinforcement and with an increase in the number of reinforcement layers. The results obtained lead to the conclusion that the choice of the value of the safety factor, which evaluates the level of stress inhomogeneity, depends on the design features of the laminates. During operation of products made of composite materials in the presence of significant accumulated damage, when the uneven distribution of stresses increases, the levels of safety factors should be adjusted.
{"title":"Analysis of the effect of the direction of reinforcement of a fibrous composite material on the inhomogeneity of localization of deformations and stresses using the method of thermoelastic response","authors":"R. Akhmetkhanov","doi":"10.26896/1028-6861-2024-90-3-62-69","DOIUrl":"https://doi.org/10.26896/1028-6861-2024-90-3-62-69","url":null,"abstract":"The purpose of the article is to study the effect of the direction of reinforcement of a composite material relative to the cyclic load on the inhomogeneity of stress distribution by the thermal method of non-destructive testing using the thermoelastic effect. This method is widely used in all industries for the control of structural elements and in research work. The degree of stress inhomogeneity is used when choosing the safety factors necessary to ensure the safety of technical objects. In this study, the thermoelastic effect is used to show the possibility of estimating the local distribution of stresses using the temperature field of the test object, proceeding from the linear relation between the temperature of the elastic body and mechanical stresses. The results of studying composite laminates (fibrous filler (fiberglass) with an epoxy matrix) with different laying of fibers with respect to the direction of loading are presented. Four laminate samples were considered: single-layer [0] and [90], three-layer [0]3 and [90]3. Statistical data and estimates of the coefficients of variation, methods of clustering and averaging over the length of the laminates the values of the temperature distribution over the surface of the laminates. The numerical characteristics of the distribution of local temperatures are obtained. It is shown that a more uniform distribution occurs when reinforcing is directed along the direction of the material loading. The integral and local characteristics of the temperature distribution in the samples are compared. The differences in the local temperature distribution depending on the laminate thickness were noted visually for single-layer and three-layer samples. A more uniform distribution of the load is also observed in the direction of reinforcement and with an increase in the number of reinforcement layers. The results obtained lead to the conclusion that the choice of the value of the safety factor, which evaluates the level of stress inhomogeneity, depends on the design features of the laminates. During operation of products made of composite materials in the presence of significant accumulated damage, when the uneven distribution of stresses increases, the levels of safety factors should be adjusted.","PeriodicalId":504498,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":" 44","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140220199","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 : 2024-03-22DOI: 10.26896/1028-6861-2024-90-3-45-51
E. G. Rakovskaya, N. Zanko, L. К. Yagunova
When cathodic protection is applied in places where paint films are damaged, an intense release of hydrogen occurs, which is removed both through diffusion and by transition from the adsorbed state on the metal surface to the subsurface layers thus leading to static hydrogen fatigue of steels, i.e., a brittle fracture occurs suddenly under static loading conditions at stress values significantly lower than the strength limit and even below the plasticity limit. We present the results of studying the impact of static tensile stresses on the hydrogen absorption by a metal during its cathodic polarization and the distribution of hydrogen over the cross-section of the metal surface. Three types of metal samples were used: wire samples made of U8A steel, plate samples made of 10KhSND steel, and semicircular samples made of Kh18N9T stainless steel with a stress concentrator. Tests of wire and semi-ring samples were carried out under a constant load and plate samples were tested under constant deformation. Polarization of wire and plate samples was carried out at different current densities for 4 days and semi-ring samples for 1 hour. At the end of polarization, the layer-by-layer distribution of hydrogen absorbed by the metal was determined by the anodic dissolution method. It is shown that with increasing deformation, the hydrogen content of the surface layers of the metal increases. Moreover, application of tensile loads and deformation of the metal by bending contribute to an increase in the amount of absorbed hydrogen and affect hydrogen distribution over the metal cross section. The thickness of the layer containing the maximum amount of hydrogen differs in steels of different compositions and structures. The results obtained can be used to protect structural steels against corrosion in sea water.
{"title":"Study of the effect of static stresses on the hydrogen content and electrochemical characteristics of steels of different types","authors":"E. G. Rakovskaya, N. Zanko, L. К. Yagunova","doi":"10.26896/1028-6861-2024-90-3-45-51","DOIUrl":"https://doi.org/10.26896/1028-6861-2024-90-3-45-51","url":null,"abstract":"When cathodic protection is applied in places where paint films are damaged, an intense release of hydrogen occurs, which is removed both through diffusion and by transition from the adsorbed state on the metal surface to the subsurface layers thus leading to static hydrogen fatigue of steels, i.e., a brittle fracture occurs suddenly under static loading conditions at stress values significantly lower than the strength limit and even below the plasticity limit. We present the results of studying the impact of static tensile stresses on the hydrogen absorption by a metal during its cathodic polarization and the distribution of hydrogen over the cross-section of the metal surface. Three types of metal samples were used: wire samples made of U8A steel, plate samples made of 10KhSND steel, and semicircular samples made of Kh18N9T stainless steel with a stress concentrator. Tests of wire and semi-ring samples were carried out under a constant load and plate samples were tested under constant deformation. Polarization of wire and plate samples was carried out at different current densities for 4 days and semi-ring samples for 1 hour. At the end of polarization, the layer-by-layer distribution of hydrogen absorbed by the metal was determined by the anodic dissolution method. It is shown that with increasing deformation, the hydrogen content of the surface layers of the metal increases. Moreover, application of tensile loads and deformation of the metal by bending contribute to an increase in the amount of absorbed hydrogen and affect hydrogen distribution over the metal cross section. The thickness of the layer containing the maximum amount of hydrogen differs in steels of different compositions and structures. The results obtained can be used to protect structural steels against corrosion in sea water.","PeriodicalId":504498,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":" 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140220248","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 : 2024-03-22DOI: 10.26896/1028-6861-2024-90-3-70-77
I. Buyanovskii, M. M. Khrushchov, V. Samusenko, S. S. Strelnikova, Yu. I. Scherbakov
The effect of the shape of contacting nonconformal elements of friction units that form an initial point contact on the tribological characteristics of lubricants during friction in the boundary lubrication mode. Point contact of rubbing bodies is realized on four-ball friction machines when testing tribological characteristics of lubricants in accordance with Russian GOST 9490–75 and GOST 23.221–84 Standards.However, these tests are carried out with the friction of standard bearing balls and does not allow taking into account the impact of materials of rubbing bodies on the results of the experiment. Therefore, two alternative designs of mandrels were developed, which allow implementation of two friction schemes: «rotating ball clamped in the spindle of the machine – three roller face planes» and «rotating ball — three cylindrical rollers». The load on the friction unit for both friction schemes, as well as in parallel on the mandrel under testing, in which three balls are installed, is the same (108 N), the spindle rotation speed is equal to 1 rpm, duration of testing is 60 min. The diameter of balls used in these experiments was 12.7 mm, and diameters of rollers were 5 and 8 mm, respectively. The material of samples was ShKh-15 tool steel or its 100Cr6 analogue. The designs of mandrels and the dimensions of samples were chosen in such a way that in all cases the contact areas of the experimental samples with the wearing (upper) ball would lie on a circle with a diameter of 7.32 mm. The tests were carried out under dry friction, and in boundary lubricated conditions in a PAO-4 polyalphaolefin oil medium, as well as in the same oil medium with the additives of oleic acid and DF-11 (a solution of zinc dialkyldithiophosphate in a low-viscosity oil). It is shown that the composition of a lubricating medium has a decisive effect on the test results (i.e., on the values of the friction coefficients and on the values of the areas of wear scars), while the geometry of the rubbing bodies, as well as the maximum Hertz stresses in the tribological contact, had a little effect on the antifriction and anti-wear characteristics of oils.
{"title":"Study of the effect of macrogeometry of rubbing steel bodies at their point contact on the tribological characteristics of lubricants under boundary lubrication conditions","authors":"I. Buyanovskii, M. M. Khrushchov, V. Samusenko, S. S. Strelnikova, Yu. I. Scherbakov","doi":"10.26896/1028-6861-2024-90-3-70-77","DOIUrl":"https://doi.org/10.26896/1028-6861-2024-90-3-70-77","url":null,"abstract":"The effect of the shape of contacting nonconformal elements of friction units that form an initial point contact on the tribological characteristics of lubricants during friction in the boundary lubrication mode. Point contact of rubbing bodies is realized on four-ball friction machines when testing tribological characteristics of lubricants in accordance with Russian GOST 9490–75 and GOST 23.221–84 Standards.However, these tests are carried out with the friction of standard bearing balls and does not allow taking into account the impact of materials of rubbing bodies on the results of the experiment. Therefore, two alternative designs of mandrels were developed, which allow implementation of two friction schemes: «rotating ball clamped in the spindle of the machine – three roller face planes» and «rotating ball — three cylindrical rollers». The load on the friction unit for both friction schemes, as well as in parallel on the mandrel under testing, in which three balls are installed, is the same (108 N), the spindle rotation speed is equal to 1 rpm, duration of testing is 60 min. The diameter of balls used in these experiments was 12.7 mm, and diameters of rollers were 5 and 8 mm, respectively. The material of samples was ShKh-15 tool steel or its 100Cr6 analogue. The designs of mandrels and the dimensions of samples were chosen in such a way that in all cases the contact areas of the experimental samples with the wearing (upper) ball would lie on a circle with a diameter of 7.32 mm. The tests were carried out under dry friction, and in boundary lubricated conditions in a PAO-4 polyalphaolefin oil medium, as well as in the same oil medium with the additives of oleic acid and DF-11 (a solution of zinc dialkyldithiophosphate in a low-viscosity oil). It is shown that the composition of a lubricating medium has a decisive effect on the test results (i.e., on the values of the friction coefficients and on the values of the areas of wear scars), while the geometry of the rubbing bodies, as well as the maximum Hertz stresses in the tribological contact, had a little effect on the antifriction and anti-wear characteristics of oils.","PeriodicalId":504498,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":" 88","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140211653","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 : 2024-03-21DOI: 10.26896/1028-6861-2024-90-3-32-38
I. Khidirov, I. J. Jaksimuratov, F. K. Khallokov
Developing the new materials with improved properties suggests study of the crystal structure and properties of multicomponent interstitial alloys. We present the results of studying the crystal structure and microhardness of TixMo1 – xCyNz interstitial alloys in massive samples with different ratios of concentrations of constituent elements. The samples obtained by self-propagating high-temperature synthesis were subjected to homogenizing annealing at 2600 K for 8 h and cooled together with the furnace. Data of neutron diffraction revealed that the alloys have a face-centered cubic crystal structure in which Ti and Mo atoms, as well as C and N, are intersubstituted and statistically located in the 4b positions and octahedral 4a positions, respectively. The Rietveld method was used to determine crystallite sizes, dislocation densities, and microstrain using X-ray diffraction patterns. The microhardness of the samples was determined by the Vickers method. It is shown that the crystallite sizes determined by the Williamson-Hall and Scherrer methods differ significantly, whereas the patterns of crystallite growth in size, as well as regularities of changes in the dislocation density and microstrains follow change in the concentration of the components in the composition. As the carbon content in the alloy increases, the crystallite sizes and microstrains decrease, and the dislocation density increases. It is revealed that the smaller the crystallite size and the higher the dislocation density, the more microhardness is displaced towards increasing the carbon content. With a change in the ratio of components in TixMo1 – xCyNz as the crystallite size and microstrains decrease and dislocation density increases, the microhardness of the alloy increases by 1.5 – 2 times compared to binary carbide and titanium nitride. The results obtained can be applied to the use of interstitial alloys in instrumental and high-temperature engineering.
开发性能更佳的新材料需要对多组分间隙合金的晶体结构和性能进行研究。我们展示了对不同组成元素浓度比例的块状样品中 TixMo1 - xCyNz 间隙合金的晶体结构和显微硬度的研究结果。通过自蔓延高温合成获得的样品在 2600 K 下均匀退火 8 小时，并随炉一起冷却。中子衍射数据显示，合金具有面心立方晶体结构，其中 Ti 原子和 Mo 原子以及 C 原子和 N 原子相互取代，并分别统计位于 4b 位和八面体 4a 位。利用 X 射线衍射图样，采用 Rietveld 方法确定了晶粒大小、位错密度和微应变。样品的显微硬度用维氏硬度法测定。结果表明，威廉森-霍尔法和舍勒法测定的晶粒大小差别很大，而晶粒大小的增长模式以及位错密度和微应变的规律性变化则随着成分中各组分浓度的变化而变化。随着合金中碳含量的增加，晶粒尺寸和微应变减小，位错密度增加。结果表明，晶粒尺寸越小，位错密度越高，显微硬度就越趋向于碳含量的增加。随着 TixMo1 - xCyNz 中成分比例的变化，晶粒尺寸和微应变减小，位错密度增加，合金的显微硬度比二元碳化物和氮化钛增加了 1.5 - 2 倍。所获得的结果可用于在仪器和高温工程中使用间隙合金。
{"title":"Study of the structure and properties of interstitial alloys TixMo1 – xCyNz","authors":"I. Khidirov, I. J. Jaksimuratov, F. K. Khallokov","doi":"10.26896/1028-6861-2024-90-3-32-38","DOIUrl":"https://doi.org/10.26896/1028-6861-2024-90-3-32-38","url":null,"abstract":"Developing the new materials with improved properties suggests study of the crystal structure and properties of multicomponent interstitial alloys. We present the results of studying the crystal structure and microhardness of TixMo1 – xCyNz interstitial alloys in massive samples with different ratios of concentrations of constituent elements. The samples obtained by self-propagating high-temperature synthesis were subjected to homogenizing annealing at 2600 K for 8 h and cooled together with the furnace. Data of neutron diffraction revealed that the alloys have a face-centered cubic crystal structure in which Ti and Mo atoms, as well as C and N, are intersubstituted and statistically located in the 4b positions and octahedral 4a positions, respectively. The Rietveld method was used to determine crystallite sizes, dislocation densities, and microstrain using X-ray diffraction patterns. The microhardness of the samples was determined by the Vickers method. It is shown that the crystallite sizes determined by the Williamson-Hall and Scherrer methods differ significantly, whereas the patterns of crystallite growth in size, as well as regularities of changes in the dislocation density and microstrains follow change in the concentration of the components in the composition. As the carbon content in the alloy increases, the crystallite sizes and microstrains decrease, and the dislocation density increases. It is revealed that the smaller the crystallite size and the higher the dislocation density, the more microhardness is displaced towards increasing the carbon content. With a change in the ratio of components in TixMo1 – xCyNz as the crystallite size and microstrains decrease and dislocation density increases, the microhardness of the alloy increases by 1.5 – 2 times compared to binary carbide and titanium nitride. The results obtained can be applied to the use of interstitial alloys in instrumental and high-temperature engineering.","PeriodicalId":504498,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":" 40","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140221949","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 : 2024-03-21DOI: 10.26896/1028-6861-2024-90-3-12-23
V. S. Ipatova, U. Bliznyuk, P. Borshchegovskaya, T. Bolotnik, A. Nikitchenko, A. P. Chernyaev, I. A. Rodin
The need to develop safe methods for radiation processing of food products to improve their quality and extend their shelf life stimulates new scientific research aimed at increasing their effectiveness. Oxidation of lipids and proteins occurred under the impact of ionizing radiation in products with a high fat and water content, such as chilled meat and fish products, leads to the formation of volatile organic compounds in the product thus giving it a specific smell and taste. During storage, biochemical processes associated with microbial enzymatic activity and auto-oxidation develop in processed refrigerated products. These processes also modify the volatile organic compounds, which affect the organoleptic properties of the product. The method of gas chromatography-mass spectrometry was used to study the behavior of volatile compounds identified in irradiated beef samples both immediately after irradiation and four days later to determine the effective dose range for the radiation processing of beef. Monitoring of the content of volatile compounds in beef samples irradiated by 1-MeV electrons within a dose range from 0.25 to 5 kGy showed that the content of certain alcohols, aldehydes, and alkanes exhibited pronounced dose- and time-dependent character. The developed mathematical model describes the dependence of the concentration of volatile compounds identified immediately after irradiation in beef samples on the irradiation dose. The model is based on the simultaneous occurrence of two competing processes: the decomposition of compounds due to their oxidation and accumulation due to oxidation of other compounds after exposure to ionizing radiation. The results obtained revealed that the effective dosage range of radiation treatment lies between 250 and 1000 Gy.
{"title":"Monitoring of changes in the concentration of volatile organic compound in beef irradiated with accelerated electrons","authors":"V. S. Ipatova, U. Bliznyuk, P. Borshchegovskaya, T. Bolotnik, A. Nikitchenko, A. P. Chernyaev, I. A. Rodin","doi":"10.26896/1028-6861-2024-90-3-12-23","DOIUrl":"https://doi.org/10.26896/1028-6861-2024-90-3-12-23","url":null,"abstract":"The need to develop safe methods for radiation processing of food products to improve their quality and extend their shelf life stimulates new scientific research aimed at increasing their effectiveness. Oxidation of lipids and proteins occurred under the impact of ionizing radiation in products with a high fat and water content, such as chilled meat and fish products, leads to the formation of volatile organic compounds in the product thus giving it a specific smell and taste. During storage, biochemical processes associated with microbial enzymatic activity and auto-oxidation develop in processed refrigerated products. These processes also modify the volatile organic compounds, which affect the organoleptic properties of the product. The method of gas chromatography-mass spectrometry was used to study the behavior of volatile compounds identified in irradiated beef samples both immediately after irradiation and four days later to determine the effective dose range for the radiation processing of beef. Monitoring of the content of volatile compounds in beef samples irradiated by 1-MeV electrons within a dose range from 0.25 to 5 kGy showed that the content of certain alcohols, aldehydes, and alkanes exhibited pronounced dose- and time-dependent character. The developed mathematical model describes the dependence of the concentration of volatile compounds identified immediately after irradiation in beef samples on the irradiation dose. The model is based on the simultaneous occurrence of two competing processes: the decomposition of compounds due to their oxidation and accumulation due to oxidation of other compounds after exposure to ionizing radiation. The results obtained revealed that the effective dosage range of radiation treatment lies between 250 and 1000 Gy.","PeriodicalId":504498,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":" 25","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140222204","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 : 2024-03-21DOI: 10.26896/1028-6861-2024-90-3-39-44
M. M. Melnikov, Y. V. Prykina, Y. Z. Vagapova
The degree of curing of protective paint-and-varnish coatings for oil country tubular goods is a parameter characterizing the completeness of their polymerization, and allows drawing a conclusion about the final physicomechanical properties and the possibility of using the material under specific conditions. This parameter is considered decisive in conducting acceptance tests and incoming quality control of pipe products with plated protective epoxy coatings despite a low accuracy of the obtained results and the impact of various instrumental factors and methodological approaches. The authors have developed a methodology for determining the curing degree of coatings based on the procedures given in regulatory documents (CSA Z245.20 Series-18, GOST R ISO 21809-2), taking into account the analysis of factors affecting the results of determining the curing degree carried out in the previous work. According to the conducted studies, the rates of heating and cooling during the measurement process, the temperature test program (in particular, the presence and duration of isothermal exposures before heating cycles), and curve processing methods were corrected and selected in the proposed methodology. The aim of this work is the analysis of the precision of the developed method for determining the curing degree of protective coatings to confirm the high accuracy of the obtained values under observing the prescribed procedure. The analysis was carried out by statistical processing of the results obtained in comparative tests performed in four testing laboratories, and included calculation of the repeatability of the results by their standard deviation, reproducibility and assessment of the acceptability of these parameters. The developed procedure for determining the curing degree of protective coatings, from sampling to processing of DSC curves, showed good precision, which indicates the reproducibility and repeatability of the proposed method. The developed method can be used as a unified sequence for determining the curing degree of paints and varnishes used as protective coatings in different laboratories.
石油国家管状产品保护性油漆和清漆涂层的固化程度是表征其聚合完全性的一个参数，可以对最终的物理机械性能和在特定条件下使用材料的可能性得出结论。尽管获得的结果准确性不高，而且受到各种仪器因素和方法的影响，但这一参数被认为是对带有电镀环氧保护涂层的管材产品进行验收测试和进货质量控制的决定性因素。作者根据规范性文件（CSA Z245.20 Series-18、GOST R ISO 21809-2）中给出的程序，并考虑到之前工作中对影响固化度测定结果的因素进行的分析，制定了一种测定涂层固化度的方法。根据所进行的研究，对测量过程中的加热和冷却速率、温度测试程序（特别是加热循环前等温暴露的存在和持续时间）以及曲线处理方法进行了修正，并在建议的方法中进行了选择。这项工作的目的是分析所开发的保护涂层固化度测定方法的精度，以确认在遵守规定程序的情况下获得的数值具有很高的准确性。分析是通过统计处理在四个测试实验室进行的对比测试所获得的结果来进行的，包括通过标准偏差计算结果的可重复性、可重复性和评估这些参数的可接受性。从取样到处理 DSC 曲线，所开发的确定保护涂层固化程度的程序显示出良好的精确性，这表明所建议的方法具有重现性和可重复性。所开发的方法可作为不同实验室测定用作保护涂层的油漆和清漆固化度的统一程序。
{"title":"Estimation of the repeatability and reproducibility of test results in determining the degree of cure of protective paint coatings using differential scanning calorimetry","authors":"M. M. Melnikov, Y. V. Prykina, Y. Z. Vagapova","doi":"10.26896/1028-6861-2024-90-3-39-44","DOIUrl":"https://doi.org/10.26896/1028-6861-2024-90-3-39-44","url":null,"abstract":"The degree of curing of protective paint-and-varnish coatings for oil country tubular goods is a parameter characterizing the completeness of their polymerization, and allows drawing a conclusion about the final physicomechanical properties and the possibility of using the material under specific conditions. This parameter is considered decisive in conducting acceptance tests and incoming quality control of pipe products with plated protective epoxy coatings despite a low accuracy of the obtained results and the impact of various instrumental factors and methodological approaches. The authors have developed a methodology for determining the curing degree of coatings based on the procedures given in regulatory documents (CSA Z245.20 Series-18, GOST R ISO 21809-2), taking into account the analysis of factors affecting the results of determining the curing degree carried out in the previous work. According to the conducted studies, the rates of heating and cooling during the measurement process, the temperature test program (in particular, the presence and duration of isothermal exposures before heating cycles), and curve processing methods were corrected and selected in the proposed methodology. The aim of this work is the analysis of the precision of the developed method for determining the curing degree of protective coatings to confirm the high accuracy of the obtained values under observing the prescribed procedure. The analysis was carried out by statistical processing of the results obtained in comparative tests performed in four testing laboratories, and included calculation of the repeatability of the results by their standard deviation, reproducibility and assessment of the acceptability of these parameters. The developed procedure for determining the curing degree of protective coatings, from sampling to processing of DSC curves, showed good precision, which indicates the reproducibility and repeatability of the proposed method. The developed method can be used as a unified sequence for determining the curing degree of paints and varnishes used as protective coatings in different laboratories.","PeriodicalId":504498,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":" 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140221036","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 : 2024-03-21DOI: 10.26896/1028-6861-2024-90-3-5-11
A. Y. Sozin, O. Y. Chernova, T. G. Sorochkina, O. Troshin, A. Kotkov
Silicon tetrachloride is a sought-after substance in the semiconductor and optoelectronics industries. High demands placed on its purity entail the need for detail information about the impurities present. The impurity composition of silicon tetrachloride obtained by different technologies (chlorination of diatomite and charcoal, disproportionation of trichlorosilane and chlorination of isotopically enriched silicon) was studied using the method of chromatography-mass spectrometry. Study of the possibility of using a DB-5MS 30 m × 0.32 mm × 0.25 μm capillary column with methylsiloxane as a stationary liquid phase to separate impurities revealed that most of the identified substances are eluted in the form of separate chromatographic peaks, which simplifies their determination. The exceptions are impurities N2, O2, Ar, as well as CO2, SiF4, and CHClF2, HCl, H2S. They were registered using the characteristic peaks of the mass spectra. To identify impurities, experimental mass spectra were compared to data from the NIST library and those known from the literature. Information on the impurity composition of SiCl4 has been expanded. It contains permanent gases, aliphatic and chlorine-containing hydrocarbons, chlorides of elements, sulfur-containing substances, and organosilicon compounds. A total of 30 compounds are identified, 19 being discovered for the first time. The mass spectrum of C2H6Cl4OSi2, which is absent in the literature, was obtained and described. For the first time, data on the impurity composition of isotopically enriched silicon tetrachloride have been obtained. A comparative analysis of the impurity composition of the samples under study was carried out and the impurities characteristic of each of them were determined. The data obtained in the study can be used in developing the technology for deep purification of silicon tetrachloride and in characterization of SiCl4 by manufacturing enterprises.
{"title":"Study of the impurity composition of silicon tetrachloride by gas chromatography-mass-spectrometry","authors":"A. Y. Sozin, O. Y. Chernova, T. G. Sorochkina, O. Troshin, A. Kotkov","doi":"10.26896/1028-6861-2024-90-3-5-11","DOIUrl":"https://doi.org/10.26896/1028-6861-2024-90-3-5-11","url":null,"abstract":"Silicon tetrachloride is a sought-after substance in the semiconductor and optoelectronics industries. High demands placed on its purity entail the need for detail information about the impurities present. The impurity composition of silicon tetrachloride obtained by different technologies (chlorination of diatomite and charcoal, disproportionation of trichlorosilane and chlorination of isotopically enriched silicon) was studied using the method of chromatography-mass spectrometry. Study of the possibility of using a DB-5MS 30 m × 0.32 mm × 0.25 μm capillary column with methylsiloxane as a stationary liquid phase to separate impurities revealed that most of the identified substances are eluted in the form of separate chromatographic peaks, which simplifies their determination. The exceptions are impurities N2, O2, Ar, as well as CO2, SiF4, and CHClF2, HCl, H2S. They were registered using the characteristic peaks of the mass spectra. To identify impurities, experimental mass spectra were compared to data from the NIST library and those known from the literature. Information on the impurity composition of SiCl4 has been expanded. It contains permanent gases, aliphatic and chlorine-containing hydrocarbons, chlorides of elements, sulfur-containing substances, and organosilicon compounds. A total of 30 compounds are identified, 19 being discovered for the first time. The mass spectrum of C2H6Cl4OSi2, which is absent in the literature, was obtained and described. For the first time, data on the impurity composition of isotopically enriched silicon tetrachloride have been obtained. A comparative analysis of the impurity composition of the samples under study was carried out and the impurities characteristic of each of them were determined. The data obtained in the study can be used in developing the technology for deep purification of silicon tetrachloride and in characterization of SiCl4 by manufacturing enterprises.","PeriodicalId":504498,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":" 34","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140221065","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 : 2024-03-21DOI: 10.26896/1028-6861-2024-90-3-24-31
N. V. Chapysheva, O. M. Miloserdova
Methods for determining nitrogen in the products of self-propagating high-temperature synthesis (SHS), i.e., titanium, aluminum, silicon, and hafnium nitrides using a Metavak-AK gas analyzer have been developed. The optimal modes of analysis have been selected: the time and temperature of degassing of the crucible with flux in the furnace, the time and temperature of purging the extraction chamber with the sample, the time of automatic dumping of the sample from the loading chamber into the crucible, the time and temperature of purging the chamber after loading, the time of removal of gaseous products of reduction melting and registration of nitrogen signals. Furnace operating programs were compiled to determine the nitrogen content in TiN, AlN, Si3N4, HfN. Reduction melting of the samples took place in a helium flow at a furnace temperature of 2700°C for TiN, AlN, HfN, and 2500°C for Si3N4. To speed up the process and complete nitrogen extraction, a metal bath was used: nickel grit in the case of titanium and hafnium nitrides, and combined Sn/Ni flux for aluminum and silicon nitrides. The nitrogen content in the studied samples was determined in the range from 0.12 up to 39.3 %wt., the relative standard deviation was 0.6 – 3.6%. The accuracy of the results obtained on a Metavak-AK gas analyzer is confirmed by the Kjeldahl and Dumas reference methods.
{"title":"Determination of nitrogen in titanium, aluminum, silicon, hafnium nitrides and compositions on their base using a Metavak-AK analyzer","authors":"N. V. Chapysheva, O. M. Miloserdova","doi":"10.26896/1028-6861-2024-90-3-24-31","DOIUrl":"https://doi.org/10.26896/1028-6861-2024-90-3-24-31","url":null,"abstract":"Methods for determining nitrogen in the products of self-propagating high-temperature synthesis (SHS), i.e., titanium, aluminum, silicon, and hafnium nitrides using a Metavak-AK gas analyzer have been developed. The optimal modes of analysis have been selected: the time and temperature of degassing of the crucible with flux in the furnace, the time and temperature of purging the extraction chamber with the sample, the time of automatic dumping of the sample from the loading chamber into the crucible, the time and temperature of purging the chamber after loading, the time of removal of gaseous products of reduction melting and registration of nitrogen signals. Furnace operating programs were compiled to determine the nitrogen content in TiN, AlN, Si3N4, HfN. Reduction melting of the samples took place in a helium flow at a furnace temperature of 2700°C for TiN, AlN, HfN, and 2500°C for Si3N4. To speed up the process and complete nitrogen extraction, a metal bath was used: nickel grit in the case of titanium and hafnium nitrides, and combined Sn/Ni flux for aluminum and silicon nitrides. The nitrogen content in the studied samples was determined in the range from 0.12 up to 39.3 %wt., the relative standard deviation was 0.6 – 3.6%. The accuracy of the results obtained on a Metavak-AK gas analyzer is confirmed by the Kjeldahl and Dumas reference methods.","PeriodicalId":504498,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":"2 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140222701","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}
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