Tingan Zhang, Daixiu Wei, Liqiang Wang, Eryi Lu, Wen Wang, Kuai-She Wang, Xiaoqing Li, Lai‐Chang Zhang, H. Kato, Weijie Lu
A series of novel α+β dual-phase Ti-Nb-Ta-Zr (Ti-(3, 5) wt.% Nb-(2, 10, 13) wt.% Ta- 2 wt.% Zr) alloys with low elastic modulus were designed by reducing the stability of β-phase under the guidelines of ab initio calculations and d-electronic theory. The alloys exhibit typical characteristics of α+β dual-phase microstructure. Among the alloys, Ti-3Nb-13Ta-2Zr alloy shows the lowest Young’s modulus (61 GPa) with highest ultimate tensile strength (779 MPa), mainly attributed to the combination of α + β dual-phase structure with stress-induced α" martensite. Moreover, {0001} α α and {001} β β textures also contribute to the reduction of elastic modulus of the alloy. Atom probe tomography analysis reveals that the elemental partitioning between α and β leads to the enrichment of solutes (Nb, Ta, Zr) in the β phase, and the elements distribution in the β phase is uneven.
{"title":"Effects of Alloying Elements on the Microstructure and Mechanical Properties of Novel α+β Dual-Phase Ti-Nb-Ta-Zr Alloys","authors":"Tingan Zhang, Daixiu Wei, Liqiang Wang, Eryi Lu, Wen Wang, Kuai-She Wang, Xiaoqing Li, Lai‐Chang Zhang, H. Kato, Weijie Lu","doi":"10.2139/ssrn.3746792","DOIUrl":"https://doi.org/10.2139/ssrn.3746792","url":null,"abstract":"A series of novel α+β dual-phase Ti-Nb-Ta-Zr (Ti-(3, 5) wt.% Nb-(2, 10, 13) wt.% Ta- 2 wt.% Zr) alloys with low elastic modulus were designed by reducing the stability of β-phase under the guidelines of ab initio calculations and d-electronic theory. The alloys exhibit typical characteristics of α+β dual-phase microstructure. Among the alloys, Ti-3Nb-13Ta-2Zr alloy shows the lowest Young’s modulus (61 GPa) with highest ultimate tensile strength (779 MPa), mainly attributed to the combination of α + β dual-phase structure with stress-induced α\" martensite. Moreover, {0001} α α and {001} β β textures also contribute to the reduction of elastic modulus of the alloy. Atom probe tomography analysis reveals that the elemental partitioning between α and β leads to the enrichment of solutes (Nb, Ta, Zr) in the β phase, and the elements distribution in the β phase is uneven.","PeriodicalId":180833,"journal":{"name":"Mechanical Properties & Deformation of Materials eJournal","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123845793","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 : 2020-11-30DOI: 10.21303/2585-6847.2020.001475
A. Kozma
The analysis of literary data on thermodynamic, thermal and elastic properties of titanium nitride TiN which included values Debye temperature θD, volume coefficient of thermal expansion αV and bulk modulus B under standard conditions is carried out. It has been shown that the known data have a significant spread of values from 20 to 43 %. The 8 most rational variants of optimizing calculations are proposed, which make it possible to reveal the most reliable values of some TiN parameters. At the same time, the minimum and maximum values of θD and αV were used from literary sources, as well as the least contradictory data on isobaric heat capacity Cp, melting temperature Tm.p and density d of TiN. To improve the calculated results, the values of θD(TiN) determined using the methods of Magnus ‒ Lindeman and Debye were also used. The Mayer’s relation was the basic test expression. The obtained values of the bulk modulus were compared with the literature data. This made it possible to distinguish the least and most reliable values of αV and θD, as well as make a refinement correction for the last value. As a result, it was found that under standard conditions, the value of θD(TiN) close to the optimal should be within 746‒769 K, and for its isochoric heat capacity CV ‒ in the range 36.55‒37.19 J/(mol×K). The range of values, after optimization, does not exceed 3 %, unlike the 20 % available in the literature. A more accurate definition of Debye temperature for TiN needs to radically refine the values of its αV and B
{"title":"Thermodynamic, Thermal and Elastic Properties of Titanium Nitride TiN: Comparison of Various Data and Determination of the Most Reliable Values","authors":"A. Kozma","doi":"10.21303/2585-6847.2020.001475","DOIUrl":"https://doi.org/10.21303/2585-6847.2020.001475","url":null,"abstract":"The analysis of literary data on thermodynamic, thermal and elastic properties of titanium nitride TiN which included values Debye temperature θD, volume coefficient of thermal expansion αV and bulk modulus B under standard conditions is carried out. It has been shown that the known data have a significant spread of values from 20 to 43 %. The 8 most rational variants of optimizing calculations are proposed, which make it possible to reveal the most reliable values of some TiN parameters. At the same time, the minimum and maximum values of θD and αV were used from literary sources, as well as the least contradictory data on isobaric heat capacity Cp, melting temperature Tm.p and density d of TiN. To improve the calculated results, the values of θD(TiN) determined using the methods of Magnus ‒ Lindeman and Debye were also used. The Mayer’s relation was the basic test expression. The obtained values of the bulk modulus were compared with the literature data. This made it possible to distinguish the least and most reliable values of αV and θD, as well as make a refinement correction for the last value. As a result, it was found that under standard conditions, the value of θD(TiN) close to the optimal should be within 746‒769 K, and for its isochoric heat capacity CV ‒ in the range 36.55‒37.19 J/(mol×K). The range of values, after optimization, does not exceed 3 %, unlike the 20 % available in the literature. A more accurate definition of Debye temperature for TiN needs to radically refine the values of its αV and B","PeriodicalId":180833,"journal":{"name":"Mechanical Properties & Deformation of Materials eJournal","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130141743","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 : 2020-10-30DOI: 10.15587/2706-5448.2020.213475
G. Mirzayeva, V. Rzayeva
Structural elements made of heterogeneous natural and artificial materials are widely used in the construction of modern building complexes and in many other areas. Among them is the use of boards and shells of different configurations. Currently, one of the most important requirements for designers and accountants is to properly assess the mechanical properties of the material of the structural element and the impact of the environment in contact during operation. Taking these into account, the mathematical solution of the problem becomes difficult, and if not, serious mistakes can be made. One of the most problematic places is considering the resistance of the external environment.
Objects of research are modern pipes exposed to the external environment.
In the paper is analysis Pasternak is one of the mathematical models that accurately reflects the elastic real properties of the environment, the model Winkler, which is characterized by two constants, the model of Karnet and the model of Rjanitsin. And is analysis their effected.
In the course of the research, the method of separation of variables and then Bubnov-Galerkin method is used, which explain relationship between the dimensionless value of frequency, the parameters that characterize the non-homogeneous of the base, and the pipe. The selection of special frequencies is carried out by selecting the corresponding special equation and boundary conditions. There are nonlinear algebraic equations and their solution using computer technology. It is shown that when the mechanical properties of the pipe vary in length, the above solution method does not work and the determination of the characteristic parameters must be performed using other approximate analytical methods. In engineering practice, it is usually sufficient to find the basic tone of the frequency. As a result of the research it is shown that the external environment effects are important for non-homogeneous pipe and should be considered in the design of the structure-ground interaction. In the future, the proposed approach and should be considered in the design of the structure non-homogenous pipe interaction.
{"title":"Analysis of Free Oscillations of a Non-Homogeneous Pipe Along Thickness and Length, Taking Into Account the Resistance of the External Environment","authors":"G. Mirzayeva, V. Rzayeva","doi":"10.15587/2706-5448.2020.213475","DOIUrl":"https://doi.org/10.15587/2706-5448.2020.213475","url":null,"abstract":"Structural elements made of heterogeneous natural and artificial materials are widely used in the construction of modern building complexes and in many other areas. Among them is the use of boards and shells of different configurations. Currently, one of the most important requirements for designers and accountants is to properly assess the mechanical properties of the material of the structural element and the impact of the environment in contact during operation. Taking these into account, the mathematical solution of the problem becomes difficult, and if not, serious mistakes can be made. One of the most problematic places is considering the resistance of the external environment.<br><br>Objects of research are modern pipes exposed to the external environment.<br><br>In the paper is analysis Pasternak is one of the mathematical models that accurately reflects the elastic real properties of the environment, the model Winkler, which is characterized by two constants, the model of Karnet and the model of Rjanitsin. And is analysis their effected.<br><br>In the course of the research, the method of separation of variables and then Bubnov-Galerkin method is used, which explain relationship between the dimensionless value of frequency, the parameters that characterize the non-homogeneous of the base, and the pipe. The selection of special frequencies is carried out by selecting the corresponding special equation and boundary conditions. There are nonlinear algebraic equations and their solution using computer technology. It is shown that when the mechanical properties of the pipe vary in length, the above solution method does not work and the determination of the characteristic parameters must be performed using other approximate analytical methods. In engineering practice, it is usually sufficient to find the basic tone of the frequency. As a result of the research it is shown that the external environment effects are important for non-homogeneous pipe and should be considered in the design of the structure-ground interaction. In the future, the proposed approach and should be considered in the design of the structure non-homogenous pipe interaction.","PeriodicalId":180833,"journal":{"name":"Mechanical Properties & Deformation of Materials eJournal","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130400982","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}
Abstract Machine learning (ML) models enable exploration of vast structural space faster than the traditional methods, such as finite element method (FEM). This makes ML models suitable for stochastic fracture problems in brittle porous materials. In this work, fully convolutional networks (FCNs) were trained to predict stress and stress concentration factor distributions in two-dimensional isotropic elastic materials with uniform porosity. We show that even with downsampled data, FCN models predict the stress distributions for a given porous structure. FCN predicted stress concentration factors 10,000 times faster than the FEM simulations. The FCN-predicted stresses combined with fracture mechanics captured the effect of porosity on the strength of porous glass. Increasing variations in pore size increased the variations in fracture strength. Furthermore, the FCN model predicts the pore configurations with the lowest and highest stresses from a set of structures, enabling ML optimization of porous microstructures for increased reliability.
{"title":"Prediction of Elastic Stresses in Porous Materials Using Fully Convolutional Networks","authors":"Ö. Keleş, Yinchuan He, B. Sirkeci-Mergen","doi":"10.2139/ssrn.3714501","DOIUrl":"https://doi.org/10.2139/ssrn.3714501","url":null,"abstract":"Abstract Machine learning (ML) models enable exploration of vast structural space faster than the traditional methods, such as finite element method (FEM). This makes ML models suitable for stochastic fracture problems in brittle porous materials. In this work, fully convolutional networks (FCNs) were trained to predict stress and stress concentration factor distributions in two-dimensional isotropic elastic materials with uniform porosity. We show that even with downsampled data, FCN models predict the stress distributions for a given porous structure. FCN predicted stress concentration factors 10,000 times faster than the FEM simulations. The FCN-predicted stresses combined with fracture mechanics captured the effect of porosity on the strength of porous glass. Increasing variations in pore size increased the variations in fracture strength. Furthermore, the FCN model predicts the pore configurations with the lowest and highest stresses from a set of structures, enabling ML optimization of porous microstructures for increased reliability.","PeriodicalId":180833,"journal":{"name":"Mechanical Properties & Deformation of Materials eJournal","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126278111","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}
The prediction of active slip systems during plastic deformation is analyzed for FCC metals under various deformation conditions (uniaxial, plane strain). The analysis reveals the orientation dependent stress contributions (Taylor factor and similar) and metallurgical effects of dislocation interaction, resulting in strain hardening and recrystallization mechanisms, i.e. nucleation and driving force for grain boundary motion. In technical terms the orientation effective strength as quantified by the Schmid- or Taylor-factor is of main interest for mechanical and anisotropic behavior of metal parts. The activated {111} slip systems and the relative amount of glide is evaluated for the case of stable orientations in uniaxial (tension, compression, bi-axial loading) and plane strain deformation (sheet rolling) in FCC metals. The classical Taylor analysis and related texture simulation models are applied under conditions of full and various relaxed constraints, considering the various boundary conditions, as described in the classical Sachs and Taylor models and derived "Relaxed Constraints" (RC) or "Grain Inter-Action" (GIA) models. These models which describe the principle effects slip system selection during plastic deformation and related texture formation and orientation stability have been analyzed for active slip systems and resulting stress contributions of stable orientations and textures of FCC metals.
{"title":"Slip System Selection and Taylor Factor Evolution in FCC Metals","authors":"J. Hirsch, Evgenij Aryshesnkij, S. Konovalov","doi":"10.2139/ssrn.3618715","DOIUrl":"https://doi.org/10.2139/ssrn.3618715","url":null,"abstract":"The prediction of active slip systems during plastic deformation is analyzed for FCC metals under various deformation conditions (uniaxial, plane strain). The analysis reveals the orientation dependent stress contributions (Taylor factor and similar) and metallurgical effects of dislocation interaction, resulting in strain hardening and recrystallization mechanisms, i.e. nucleation and driving force for grain boundary motion. In technical terms the orientation effective strength as quantified by the Schmid- or Taylor-factor is of main interest for mechanical and anisotropic behavior of metal parts. The activated {111} slip systems and the relative amount of glide is evaluated for the case of stable orientations in uniaxial (tension, compression, bi-axial loading) and plane strain deformation (sheet rolling) in FCC metals. The classical Taylor analysis and related texture simulation models are applied under conditions of full and various relaxed constraints, considering the various boundary conditions, as described in the classical Sachs and Taylor models and derived \"Relaxed Constraints\" (RC) or \"Grain Inter-Action\" (GIA) models. These models which describe the principle effects slip system selection during plastic deformation and related texture formation and orientation stability have been analyzed for active slip systems and resulting stress contributions of stable orientations and textures of FCC metals.","PeriodicalId":180833,"journal":{"name":"Mechanical Properties & Deformation of Materials eJournal","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115707659","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}
A. Anssari-Benam, Y. Tseng, Gerhard A. Holzapfel, A. Bucchi
In this study we investigate the rate-dependency of the mechanical behaviour of semilunar heart valves under biaxial deformation, from quasi-static to physiological loading rates. This work extends and complements our previous undertaking, where the rate-dependency in the mechanical behaviour of semilunar valve specimens was documented in sub-physiological rate domains (Acta Biomater. 2019; https://doi.org/10.1016/j.actbio.2019.02.008). For the first time we demonstrate herein that the stress-stretch curves obtained from specimens under physiological rates too are markedly different to those at sufficiently lower rates and at quasi-static conditions. The results importantly underline that the mechanical behaviour of semilunar heart valves is rate dependent, and the physiological mechanical behaviour of the valves may not be correctly obtained via material characterisation tests at arbitrary low deformation rates. Presented results in this work provide an inclusive dataset for material characterisation and modelling of semilunar heart valves across a 10,000 fold deformation rate, both under equi-biaxial and 1:3 ratio deformation rates. The important application of these results is to inform the development of appropriate mechanical testing protocols, as well as devising new models, for suitable determination of the rate-dependent constitutive mechanical behaviour of the semilunar valves.
{"title":"Rate-Dependent Mechanical Behaviour of Semilunar Valves Under Biaxial Deformation: From Quasi-Static to Physiological Loading Rates","authors":"A. Anssari-Benam, Y. Tseng, Gerhard A. Holzapfel, A. Bucchi","doi":"10.2139/ssrn.3455094","DOIUrl":"https://doi.org/10.2139/ssrn.3455094","url":null,"abstract":"In this study we investigate the rate-dependency of the mechanical behaviour of semilunar heart valves under biaxial deformation, from quasi-static to physiological loading rates. This work extends and complements our previous undertaking, where the rate-dependency in the mechanical behaviour of semilunar valve specimens was documented in sub-physiological rate domains (Acta Biomater. 2019; https://doi.org/10.1016/j.actbio.2019.02.008). For the first time we demonstrate herein that the stress-stretch curves obtained from specimens under physiological rates too are markedly different to those at sufficiently lower rates and at quasi-static conditions. The results importantly underline that the mechanical behaviour of semilunar heart valves is rate dependent, and the physiological mechanical behaviour of the valves may not be correctly obtained via material characterisation tests at arbitrary low deformation rates. Presented results in this work provide an inclusive dataset for material characterisation and modelling of semilunar heart valves across a 10,000 fold deformation rate, both under equi-biaxial and 1:3 ratio deformation rates. The important application of these results is to inform the development of appropriate mechanical testing protocols, as well as devising new models, for suitable determination of the rate-dependent constitutive mechanical behaviour of the semilunar valves.","PeriodicalId":180833,"journal":{"name":"Mechanical Properties & Deformation of Materials eJournal","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134244667","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}
Residual stress distributions as a function of depth in APS TBCs after different heat treatment times have been measured by synchrotron XRD. Three types of residual stress distribution were observed. The first type was a low stress state from the as-received sample; the second type was a compressive stress state increasing from the surface to the interface with a discontinuous "jump feature" in the trend near the interface; the third type of residual stress distribution has two "jump" features in the trend, one was observed near the sample surface and the other near the interface. To understand the double "jump" features in the third kind of trend, the 3D microstructures of the measured samples were systematically measured X-ray μ-CT. Vertical cracks and edge cracks were observed. We have shown by image based modelling that the vertical cracks do not have a large effect on the residual stress distribution and that edge cracks are related to the "jump features" near the sample surface. The edge crack can be observed in all the measured samples with the third kind of the residual stress trend; and the measured samples with the second kind of the residual stress trend are crack free. The relationship between the middle and the through edge cracks and the residual stress distribution was also investigated by image based modelling. It was found that the middle crack can also cause a "jump feature" near the sample surface while the through edge crack seems to not have a large effect on the residual stress distribution. A semi-destructive method was developed to determine the existence and the position of horizontal cracks in the APS TBC samples based on the above findings.
{"title":"Direct Correlation of the Crack Distribution in APS Thermal Barrier Coatings with the Measured Synchrotron XRD Residual Stress Distribution","authors":"C. Lia, R. Cernik","doi":"10.2139/ssrn.3513103","DOIUrl":"https://doi.org/10.2139/ssrn.3513103","url":null,"abstract":"Residual stress distributions as a function of depth in APS TBCs after different heat treatment times have been measured by synchrotron XRD. Three types of residual stress distribution were observed. The first type was a low stress state from the as-received sample; the second type was a compressive stress state increasing from the surface to the interface with a discontinuous \"jump feature\" in the trend near the interface; the third type of residual stress distribution has two \"jump\" features in the trend, one was observed near the sample surface and the other near the interface. To understand the double \"jump\" features in the third kind of trend, the 3D microstructures of the measured samples were systematically measured X-ray μ-CT. Vertical cracks and edge cracks were observed. We have shown by image based modelling that the vertical cracks do not have a large effect on the residual stress distribution and that edge cracks are related to the \"jump features\" near the sample surface. The edge crack can be observed in all the measured samples with the third kind of the residual stress trend; and the measured samples with the second kind of the residual stress trend are crack free. The relationship between the middle and the through edge cracks and the residual stress distribution was also investigated by image based modelling. It was found that the middle crack can also cause a \"jump feature\" near the sample surface while the through edge crack seems to not have a large effect on the residual stress distribution. A semi-destructive method was developed to determine the existence and the position of horizontal cracks in the APS TBC samples based on the above findings.","PeriodicalId":180833,"journal":{"name":"Mechanical Properties & Deformation of Materials eJournal","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133602715","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}
K. Das, Trina Dutta, S. Chattaraj, Aditya Dasgupta, T. Mondal, A. Chakraborty, Akash Roy, Moutoshi Das
Concrete which has been made from waste of concrete that are eco friendly is termed as green concrete. 8 to 10% of world total CO2 emission comes from production of cement, when lime stone and crushed clay are heated at high temperature during the production. Green concrete uses waste material at least one of its component and environment destruction did not occur during the time of production. Researchers have conducted various experiments to find perfect solution for sustainable construction and from them green concrete is one. Here an effort has been made to inculcate the ideas about the mechanical and rheological properties of Green Concrete grade M25 by replacing cement with micro silica, fine and coarse aggregates with crushed recycled aggregates and crushed glass from 10 to 30% replacement by weight of the materials. And they have been compared with conventional mixed concrete. It has been observed that when cement, sand and coarse aggregate is replaced by 30% 0f micro silica, 20% crushed recycled aggregates and 30% crushed glass it has shown a better result in mechanical and fresh property with respect to conventional concrete.
{"title":"Study Towards Green Concrete for Better Sustainable Construction","authors":"K. Das, Trina Dutta, S. Chattaraj, Aditya Dasgupta, T. Mondal, A. Chakraborty, Akash Roy, Moutoshi Das","doi":"10.2139/ssrn.3511629","DOIUrl":"https://doi.org/10.2139/ssrn.3511629","url":null,"abstract":"Concrete which has been made from waste of concrete that are eco friendly is termed as green concrete. 8 to 10% of world total CO2 emission comes from production of cement, when lime stone and crushed clay are heated at high temperature during the production. Green concrete uses waste material at least one of its component and environment destruction did not occur during the time of production. Researchers have conducted various experiments to find perfect solution for sustainable construction and from them green concrete is one. Here an effort has been made to inculcate the ideas about the mechanical and rheological properties of Green Concrete grade M25 by replacing cement with micro silica, fine and coarse aggregates with crushed recycled aggregates and crushed glass from 10 to 30% replacement by weight of the materials. And they have been compared with conventional mixed concrete. It has been observed that when cement, sand and coarse aggregate is replaced by 30% 0f micro silica, 20% crushed recycled aggregates and 30% crushed glass it has shown a better result in mechanical and fresh property with respect to conventional concrete.","PeriodicalId":180833,"journal":{"name":"Mechanical Properties & Deformation of Materials eJournal","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129556050","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}
Shenghang Xu, M. Du, Jia Li, K. Yan, B. Cai, Quanfeng He, Q. Fang, O. Magdysyuk, Bin Liu, Yong Yang, Yong Liu
Nature materials, such as bones and nacre, achieve excellent balance of toughness and strength via a hierarchical "brick-and-mortar" microstructure, which is an attractive model for engineering materials design. Here, we produced nacre-like Ti-Ta metallic composites via a powder metallurgy process, during which milled powders were sintered by spark plasma sintering, followed by hot rolling and then annealing. The structure consists of soft Ta-enriched regions and hard Ti-enriched regions in a hierarchical and laminated fashion. The microstructural heterogeneity spans several scales due to the diffusion between Ti and Ta. This yields a novel metal-metal composite with a balanced combination of strength and ductility (1226 MPa ultimate tensile strength and 20.8% elongation), outperforming most of conventional Ti based alloys and composites. Via complementary in situ synchrotron X-ray diffraction and electron microscopies, it is found out that multiple micromechanisms are active, including nano-particle and dislocation localized strengthening as well as a "phase transformation induced plasticity. The manufacturing route developed here is versatile, capable of making high performance bio-mimic metallic composites.
{"title":"Bio-Mimic Ti-Ta Composite with Hierarchical 'Brick-and-Mortar' Microstructure","authors":"Shenghang Xu, M. Du, Jia Li, K. Yan, B. Cai, Quanfeng He, Q. Fang, O. Magdysyuk, Bin Liu, Yong Yang, Yong Liu","doi":"10.2139/ssrn.3425440","DOIUrl":"https://doi.org/10.2139/ssrn.3425440","url":null,"abstract":"Nature materials, such as bones and nacre, achieve excellent balance of toughness and strength via a hierarchical \"brick-and-mortar\" microstructure, which is an attractive model for engineering materials design. Here, we produced nacre-like Ti-Ta metallic composites via a powder metallurgy process, during which milled powders were sintered by spark plasma sintering, followed by hot rolling and then annealing. The structure consists of soft Ta-enriched regions and hard Ti-enriched regions in a hierarchical and laminated fashion. The microstructural heterogeneity spans several scales due to the diffusion between Ti and Ta. This yields a novel metal-metal composite with a balanced combination of strength and ductility (1226 MPa ultimate tensile strength and 20.8% elongation), outperforming most of conventional Ti based alloys and composites. Via complementary in situ synchrotron X-ray diffraction and electron microscopies, it is found out that multiple micromechanisms are active, including nano-particle and dislocation localized strengthening as well as a \"phase transformation induced plasticity. The manufacturing route developed here is versatile, capable of making high performance bio-mimic metallic composites.","PeriodicalId":180833,"journal":{"name":"Mechanical Properties & Deformation of Materials eJournal","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125732330","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}
Daixiu Wei, Xiaoqing Li, S. Schönecker, Jing Jiang, W. Choi, Byeong-Joo Lee, Hyoung-Seop Kim, A. Chiba, H. Kato
Abstract Face-centered cubic (fcc)-phase high-entropy alloys (HEAs) have attracted much academic interest, with the stacking fault energy (SFE) playing an important role in regulating their mechanical behaviors. Here, we revealed the principles for regulating both the elastic and plastic behaviors by composition modification and Mo addition in an fcc-phase quaternary CoCrFeNi system with the assistance of ab initio and thermodynamics calculations. An increase in Co content and a decrease in Fe and Ni contents reduced the fcc phase stability and SFE, but enhanced the elastic modulus, anisotropy, and lattice friction stress. A minor substitution of Co by Mo increased the lattice constant, but decreased the SFE and elastic modulus. Based on these findings, we developed a series of strong and ductile metastable fcc-phase CoxCr25(FeNi)70-xMo5 (x = 30, 40, 50) HEAs with mechanical properties superior to those of the CoCrFeNi HEAs. The careful investigation revealed that the enhanced mechanical properties are due to the Mo-addition-induced strengthening accompanied with a low-SFE-induced restriction of planar behavior of dislocations, mechanical twinning, and strain-induced martensitic transformation. The findings shed light on the development of high-performance HEAs.
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