Wei Zhang, S. Lv, Yijing Lv, Xiaosheng Gao, T. Srivatsan
In this paper, a coating–substrate interfacial corrosion test method was developed to simulate and study the failure processes occurring at the coating interface as a direct consequence of environment-induced degradation or corrosion. It was found that the corrosion-induced failure rate of the coating–substrate interface upon exposure to an aggressive corrosive medium was high. Microscopic pits tend to appear at the interface of the coating and the substrate. The permeation channel at the coating interface did cause the corrosive medium, primarily the chloride ions, to gradually diffuse from the sides of the sample to the inner surface of the interface thereby enabling the initiation and continued progression of “local” corrosion. The process for failure due essentially to corrosion of the coating was established, while ensuring to include the infiltration phase, the presence of “local” corrosion phases, expansion, if any, due to corrosion, and eventually culminating in failure. Based on the experimental results, a finite element simulation of the “local” corrosion occurring at the coating interface was executed. The results revealed the microscopic pits at the interface to progressively increase the “local” stress concentration on the surface of the substrate but were found to have little influence on overall stress distribution in the coating. It was also found the shape of the etch pit had an effect on failure expansion under the influence of stress. The numerical method can be used to predict structural failure caused by corrosion pits at the interface of the coating–substrate system in an aggressive environment.
{"title":"Corrosion Behavior of an Anti-Icing Coating on an Aluminum Alloy: An Experimental and Numerical Study","authors":"Wei Zhang, S. Lv, Yijing Lv, Xiaosheng Gao, T. Srivatsan","doi":"10.1115/1.4049589","DOIUrl":"https://doi.org/10.1115/1.4049589","url":null,"abstract":"\u0000 In this paper, a coating–substrate interfacial corrosion test method was developed to simulate and study the failure processes occurring at the coating interface as a direct consequence of environment-induced degradation or corrosion. It was found that the corrosion-induced failure rate of the coating–substrate interface upon exposure to an aggressive corrosive medium was high. Microscopic pits tend to appear at the interface of the coating and the substrate. The permeation channel at the coating interface did cause the corrosive medium, primarily the chloride ions, to gradually diffuse from the sides of the sample to the inner surface of the interface thereby enabling the initiation and continued progression of “local” corrosion. The process for failure due essentially to corrosion of the coating was established, while ensuring to include the infiltration phase, the presence of “local” corrosion phases, expansion, if any, due to corrosion, and eventually culminating in failure. Based on the experimental results, a finite element simulation of the “local” corrosion occurring at the coating interface was executed. The results revealed the microscopic pits at the interface to progressively increase the “local” stress concentration on the surface of the substrate but were found to have little influence on overall stress distribution in the coating. It was also found the shape of the etch pit had an effect on failure expansion under the influence of stress. The numerical method can be used to predict structural failure caused by corrosion pits at the interface of the coating–substrate system in an aggressive environment.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"39 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87419282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Advances in manufacturing technologies have led to the development of a new approach to material selection, in which architectured designs can be created to achieve a specific mechanical objective. Cellular lattice structures have been at the forefront of this movement due to the ability to tailor their mechanical response through tuning of the topology, surface thickness, cell size, and cell density. In this work, the mechanical properties of additively manufactured periodic cellular lattices are evaluated and compared, primarily through the topology and surface thickness parameters. The evaluated lattices were based upon triply periodic minimal surfaces (TPMS), including novel variations on the base TPMS designs, which have not been tested previously. These lattices were fabricated out of Inconel 718 (IN718) through the selective laser melting (SLM) process. Specimens were tested under uniaxial compression, and the resultant mechanical properties were determined. Further discussion of the fabrication quality and deformation behavior of the lattices is provided. Results of this work indicate that the Diamond TPMS lattice has superior mechanical properties to the other lattices tested. Additionally, with the exception of the primitive TPMS lattice, the base TPMS designs exhibited superior mechanical performance to their derivative lattice designs.
{"title":"Mechanical Properties of Additively Manufactured Periodic Cellular Structures and Design Variations","authors":"Derek G. Spear, A. Palazotto, R. Kemnitz","doi":"10.1115/1.4050939","DOIUrl":"https://doi.org/10.1115/1.4050939","url":null,"abstract":"\u0000 Advances in manufacturing technologies have led to the development of a new approach to material selection, in which architectured designs can be created to achieve a specific mechanical objective. Cellular lattice structures have been at the forefront of this movement due to the ability to tailor their mechanical response through tuning of the topology, surface thickness, cell size, and cell density. In this work, the mechanical properties of additively manufactured periodic cellular lattices are evaluated and compared, primarily through the topology and surface thickness parameters. The evaluated lattices were based upon triply periodic minimal surfaces (TPMS), including novel variations on the base TPMS designs, which have not been tested previously. These lattices were fabricated out of Inconel 718 (IN718) through the selective laser melting (SLM) process. Specimens were tested under uniaxial compression, and the resultant mechanical properties were determined. Further discussion of the fabrication quality and deformation behavior of the lattices is provided. Results of this work indicate that the Diamond TPMS lattice has superior mechanical properties to the other lattices tested. Additionally, with the exception of the primitive TPMS lattice, the base TPMS designs exhibited superior mechanical performance to their derivative lattice designs.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"24 1","pages":"1-48"},"PeriodicalIF":1.2,"publicationDate":"2021-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83461845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Out-of-plane compression experiments with the strain rate from 0.0001/s to 1000/s are performed on a three-dimensional (3D) fine weave-pierced Carbon/Carbon (C/C) composite using a universal testing machine, a high-speed testing machine, and a split Hopkinson pressure bar (SHPB). The compressive failure mechanism of the composite is analyzed by a multi-scale analysis method, which ranges from micro-scale defect propagation, through meso-scale microstructure failure, to macro-scale material failure. In order to predict the out-of-plane compressive properties of 3D fine weave-pierced C/C composite at different strain rates, a strain-rate-dependent compressive constitutive model is proposed. The results show that the out-of-plane compressive behavior of the 3D fine weave-pierced C/C composite is sensitive to strain rate. With increasing the strain rate, the initial compressive modulus, the maximum stress, and the strain at the maximum stress increase. The difference in mechanical behavior between quasi-static and high strain rate compression is owing to the strain rate effect on the defect propagation of the 3D fine weave-pierced C/C composite. The proposed constitutive model matches well with the experimental data.
{"title":"Dynamic Out-of-Plane Compressive Failure Mechanism of Carbon/Carbon Composite: Strain Rate Effect on the Defect Propagation and Microstructure Failure","authors":"G. Fei, Q. Fei, Yanbin Li, N. Gupta","doi":"10.1115/1.4050889","DOIUrl":"https://doi.org/10.1115/1.4050889","url":null,"abstract":"Out-of-plane compression experiments with the strain rate from 0.0001/s to 1000/s are performed on a three-dimensional (3D) fine weave-pierced Carbon/Carbon (C/C) composite using a universal testing machine, a high-speed testing machine, and a split Hopkinson pressure bar (SHPB). The compressive failure mechanism of the composite is analyzed by a multi-scale analysis method, which ranges from micro-scale defect propagation, through meso-scale microstructure failure, to macro-scale material failure. In order to predict the out-of-plane compressive properties of 3D fine weave-pierced C/C composite at different strain rates, a strain-rate-dependent compressive constitutive model is proposed. The results show that the out-of-plane compressive behavior of the 3D fine weave-pierced C/C composite is sensitive to strain rate. With increasing the strain rate, the initial compressive modulus, the maximum stress, and the strain at the maximum stress increase. The difference in mechanical behavior between quasi-static and high strain rate compression is owing to the strain rate effect on the defect propagation of the 3D fine weave-pierced C/C composite. The proposed constitutive model matches well with the experimental data.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"101 1","pages":"1-31"},"PeriodicalIF":1.2,"publicationDate":"2021-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89920484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Viscoelastic (VE) dampers are a kind of effective passive vibration control device and widely used to attenuate structural vibration. In this article, experimental study and multiscale modeling analysis on the VE damper for reducing wind-excited vibration are carried out. First, an experimental study on VE damper is conducted to reveal the dynamic properties of VE damper. The experimental results show that the dynamic properties of VE material are influenced by excitation frequency and insignificantly affected by displacement amplitude, and the VE material has good energy dissipation capacity. Second, the damping mechanism of VE damper is analyzed from micro-perspectives by considering the influence of cross-linked and free molecular chain networks. Then, a novel type spherical chain network model based on the chain network microstructure is proposed. The proposed model is verified by comparing the experimental data and the mathematical results, which indicates that the proposed model can accurately describe the dynamic properties of VE damper affected by different temperatures, frequencies, and displacements.
{"title":"Study on Experiment and Modeling of Viscoelastic Damper Considering Interfacial Effect of Matrix Rubber/Carbon Black","authors":"Teng Ge, Zhao-dong Xu, F. Yuan","doi":"10.1115/1.4050848","DOIUrl":"https://doi.org/10.1115/1.4050848","url":null,"abstract":"\u0000 Viscoelastic (VE) dampers are a kind of effective passive vibration control device and widely used to attenuate structural vibration. In this article, experimental study and multiscale modeling analysis on the VE damper for reducing wind-excited vibration are carried out. First, an experimental study on VE damper is conducted to reveal the dynamic properties of VE damper. The experimental results show that the dynamic properties of VE material are influenced by excitation frequency and insignificantly affected by displacement amplitude, and the VE material has good energy dissipation capacity. Second, the damping mechanism of VE damper is analyzed from micro-perspectives by considering the influence of cross-linked and free molecular chain networks. Then, a novel type spherical chain network model based on the chain network microstructure is proposed. The proposed model is verified by comparing the experimental data and the mathematical results, which indicates that the proposed model can accurately describe the dynamic properties of VE damper affected by different temperatures, frequencies, and displacements.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"36 1","pages":"1-28"},"PeriodicalIF":1.2,"publicationDate":"2021-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91015875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nano-aluminum powders and nano-ZrO2 reinforcement particles were mechanically milled and hot-pressed to produce Al–ZrO2 nanocomposites. Microstructure and mechanical properties of Al–ZrO2 nanocomposites were investigated using scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analyses and by performing hardness and compression testing. Uniform particle distribution was obtained up to 3 wt% of nano-ZrO2 particles using nano-sized aluminum powders as matrix powders and by applying a mechanical milling process. As the nano-ZrO2 reinforcement particles were uniformly distributed in the matrix, the relative density of the Al–ZrO2 nanocomposites increased up to 3 wt% nano-ZrO2 particles with an increase in milling time; on the other hand, the relative density decreased and the porosity increased with high-weight fractions (>3 wt%) of nano-ZrO2 particles due to the negative combined effect of less densification and an increase in the number of particle clusters. The hardness and compressive strength of the Al–ZrO2 nanocomposites improved despite increased porosity. However, the compressive strength of Al–ZrO2 nanocomposites with a high amount (>3 wt%) of nano-ZrO2 particles began to decrease due to the negative combined effect of the less densification of the powder particles and the clustering of nano-ZrO2 reinforcement particles. The brittle-ductile fracture occurred in the Al–ZrO2 nanocomposites.
{"title":"Effect of ZrO2 Nanoparticles and Mechanical Milling on Microstructure and Mechanical Properties of Al–ZrO2 Nanocomposites","authors":"Sinem Aktaş, Ege A Diler","doi":"10.1115/1.4050726","DOIUrl":"https://doi.org/10.1115/1.4050726","url":null,"abstract":"\u0000 Nano-aluminum powders and nano-ZrO2 reinforcement particles were mechanically milled and hot-pressed to produce Al–ZrO2 nanocomposites. Microstructure and mechanical properties of Al–ZrO2 nanocomposites were investigated using scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analyses and by performing hardness and compression testing. Uniform particle distribution was obtained up to 3 wt% of nano-ZrO2 particles using nano-sized aluminum powders as matrix powders and by applying a mechanical milling process. As the nano-ZrO2 reinforcement particles were uniformly distributed in the matrix, the relative density of the Al–ZrO2 nanocomposites increased up to 3 wt% nano-ZrO2 particles with an increase in milling time; on the other hand, the relative density decreased and the porosity increased with high-weight fractions (>3 wt%) of nano-ZrO2 particles due to the negative combined effect of less densification and an increase in the number of particle clusters. The hardness and compressive strength of the Al–ZrO2 nanocomposites improved despite increased porosity. However, the compressive strength of Al–ZrO2 nanocomposites with a high amount (>3 wt%) of nano-ZrO2 particles began to decrease due to the negative combined effect of the less densification of the powder particles and the clustering of nano-ZrO2 reinforcement particles. The brittle-ductile fracture occurred in the Al–ZrO2 nanocomposites.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"14 1","pages":"1-28"},"PeriodicalIF":1.2,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82917324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High entropy alloys (HEAs) are primarily known for their high strength and high thermal stability. These alloys have recently been studied for high strain rate applications as well. HEAs have been observed to exhibit different properties when subjected to different strain rates. Very few published results on HEAs are available for high strain rate loading conditions. In addition, modeling and simulation work of microstructural details, such as grain boundary and precipitates of HEAs have not yet been investigated. However, at an atomistic length scale, molecular dynamics simulation works of HEAs have already been published. In this study, a detailed microstructural analysis of plastic deformation of the material under high strain rate loading has been performed using dislocation density based crystal plasticity finite element modeling. The primary objective is, therefore, to assess the strengthening effects due to precipitates on a particular high entropy alloy Al0.3CoCrFeNi with ultrafine grains having randomly distributed NiAl precipitates.
{"title":"Effect of Precipitates on Plastic Deformation Behavior of High Entropy Alloy Al0.3CoCrFeNi Under High Strain Rate Loading","authors":"P. Das, Vishal Kumar, Prasenjit Khanikar","doi":"10.1115/1.4048607","DOIUrl":"https://doi.org/10.1115/1.4048607","url":null,"abstract":"\u0000 High entropy alloys (HEAs) are primarily known for their high strength and high thermal stability. These alloys have recently been studied for high strain rate applications as well. HEAs have been observed to exhibit different properties when subjected to different strain rates. Very few published results on HEAs are available for high strain rate loading conditions. In addition, modeling and simulation work of microstructural details, such as grain boundary and precipitates of HEAs have not yet been investigated. However, at an atomistic length scale, molecular dynamics simulation works of HEAs have already been published. In this study, a detailed microstructural analysis of plastic deformation of the material under high strain rate loading has been performed using dislocation density based crystal plasticity finite element modeling. The primary objective is, therefore, to assess the strengthening effects due to precipitates on a particular high entropy alloy Al0.3CoCrFeNi with ultrafine grains having randomly distributed NiAl precipitates.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"2 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87662583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study presents the elastic properties and nonlinear elasticity of the two-dimensional noncarbon nanomaterials of hexagonal lattice structures having molecular structure XY. Four nitride-based and two phosphide-based two-dimensional nanomaterials, having graphene-like hexagonal lattice structure, are considered in the present study. The four empirical parameters associated with the attractive and repulsive terms of the Tersoff–Brenner potential are calibrated for noncarbon nanomaterials and tested for elastic properties, nonlinear constitutive behavior, bending modulus, bending and torsional energy. The mathematical identities for the tangent constitutive matrix in terms of the interatomic potential function are derived through an atomistic–continuum coupled multiscale framework of the extended version of Cauchy–Born rule. The results obtained using newly calibrated empirical parameters for cohesive energy, bond length, elastic properties, and bending rigidity are compared with those reported in the literature through experimental investigations and quantum mechanical calculations. The continuum approximation is attained through the finite element method. Multiscale evaluations for elastic properties and nonlinear stretching of the nanosheets under in-plane loads are also compared with those obtained from atomistic simulations.
{"title":"Elastic Properties and Nonlinear Elasticity of the Noncarbon Hexagonal Lattice Nanomaterials Based on the Multiscale Modeling","authors":"S. Singh, B. M. R. Raj, K. Mali, G. Watts","doi":"10.1115/1.4048874","DOIUrl":"https://doi.org/10.1115/1.4048874","url":null,"abstract":"\u0000 This study presents the elastic properties and nonlinear elasticity of the two-dimensional noncarbon nanomaterials of hexagonal lattice structures having molecular structure XY. Four nitride-based and two phosphide-based two-dimensional nanomaterials, having graphene-like hexagonal lattice structure, are considered in the present study. The four empirical parameters associated with the attractive and repulsive terms of the Tersoff–Brenner potential are calibrated for noncarbon nanomaterials and tested for elastic properties, nonlinear constitutive behavior, bending modulus, bending and torsional energy. The mathematical identities for the tangent constitutive matrix in terms of the interatomic potential function are derived through an atomistic–continuum coupled multiscale framework of the extended version of Cauchy–Born rule. The results obtained using newly calibrated empirical parameters for cohesive energy, bond length, elastic properties, and bending rigidity are compared with those reported in the literature through experimental investigations and quantum mechanical calculations. The continuum approximation is attained through the finite element method. Multiscale evaluations for elastic properties and nonlinear stretching of the nanosheets under in-plane loads are also compared with those obtained from atomistic simulations.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"7 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90235937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The tearing response of sheets of nonwoven fiber material is investigated. It addresses the question on how notch length and notch geometry is related to the tearing strength and tearing processes. The system considered consists of elastic-brittle fibers connected by strong interfiber bonds. Fiber fracture is the only failure mechanism. For a random fiber orientation case, deformation of the unnotched specimen occurs by long-range fiber chains connecting the load inducing boundaries, and failure is by tearing the cross section. The strength of the notched random fiber sheets is well described by a net section criterion, independent of the notch geometry. For a fiber orientation with symmetry relative to the loading direction, tensile loading is transferred by formation of the X-shaped fiber chains centered in the specimen. The subsequent failure occurs along the fiber chain by shear. Thus, the tearing strength is independent of the notch depth in double-edge notched and single-edge notched specimens, when the presence of shallow notch does not disrupt the force chains in the model. As the notch disturbs the fiber chains, alternative shear failure path forms near the notch tip, leading to a dependence of failure strength on the notch geometry. Then, the failure strength of notched nonwoven networks is described by a shear strength and a notch geometry term.
{"title":"The Effect of Notches on the Failure of Two-Dimensional Nonwoven Fiber Networks","authors":"Yinglong Chen, T. Siegmund","doi":"10.1115/1.4048282","DOIUrl":"https://doi.org/10.1115/1.4048282","url":null,"abstract":"\u0000 The tearing response of sheets of nonwoven fiber material is investigated. It addresses the question on how notch length and notch geometry is related to the tearing strength and tearing processes. The system considered consists of elastic-brittle fibers connected by strong interfiber bonds. Fiber fracture is the only failure mechanism. For a random fiber orientation case, deformation of the unnotched specimen occurs by long-range fiber chains connecting the load inducing boundaries, and failure is by tearing the cross section. The strength of the notched random fiber sheets is well described by a net section criterion, independent of the notch geometry. For a fiber orientation with symmetry relative to the loading direction, tensile loading is transferred by formation of the X-shaped fiber chains centered in the specimen. The subsequent failure occurs along the fiber chain by shear. Thus, the tearing strength is independent of the notch depth in double-edge notched and single-edge notched specimens, when the presence of shallow notch does not disrupt the force chains in the model. As the notch disturbs the fiber chains, alternative shear failure path forms near the notch tip, leading to a dependence of failure strength on the notch geometry. Then, the failure strength of notched nonwoven networks is described by a shear strength and a notch geometry term.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"19 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81089887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The dissimilar titanium alloys Ti70/TA5 are welded by using electron beam welding. The microstructure and mechanical properties of the welded joints are systematically investigated, and the welding parameters are optimized. Results show that the fusion zone (FZ) is mainly α’ martensite, and the heat-affected zone (HAZ) in the Ti70 side consists of fine α’ martensite, residual α phase, and original β phase, while the HAZ in the TA5 side is composed of coarser α phase, serrated and acicular α phase. Transmission electron microscope (TEM) analysis demonstrates that the martensite in the FZ presents the lath-like morphology. There are high-density dislocations within martensite, which has a certain orientation relationship with the β phase. Under the appropriate welding procedure, the tensile strength of the dissimilar joint is close to that of the TA5 base metal. The joint fracture dominantly presents the characteristic of ductile fracture. During welding, electron beam scanning is beneficial to improving the solidification of molten pool and grain refinement; thus, the mechanical property of the welded joint is increased to a certain extent.
{"title":"Microstructural Evolution and Mechanical Properties of Electron Beam–Welded Ti70/TA5 Dissimilar Joint","authors":"Donghui Wang, Shaogang Wang, Wen Zhang","doi":"10.1115/1.4048283","DOIUrl":"https://doi.org/10.1115/1.4048283","url":null,"abstract":"The dissimilar titanium alloys Ti70/TA5 are welded by using electron beam welding. The microstructure and mechanical properties of the welded joints are systematically investigated, and the welding parameters are optimized. Results show that the fusion zone (FZ) is mainly α’ martensite, and the heat-affected zone (HAZ) in the Ti70 side consists of fine α’ martensite, residual α phase, and original β phase, while the HAZ in the TA5 side is composed of coarser α phase, serrated and acicular α phase. Transmission electron microscope (TEM) analysis demonstrates that the martensite in the FZ presents the lath-like morphology. There are high-density dislocations within martensite, which has a certain orientation relationship with the β phase. Under the appropriate welding procedure, the tensile strength of the dissimilar joint is close to that of the TA5 base metal. The joint fracture dominantly presents the characteristic of ductile fracture. During welding, electron beam scanning is beneficial to improving the solidification of molten pool and grain refinement; thus, the mechanical property of the welded joint is increased to a certain extent.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"47 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80251961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding a magnesium alloy sheet's response to load reversals is important to accurately simulate and optimize a component's manufacturing process. Through this research, the room temperature compression-tension and tension-compression experiments with strains up to ∼12% are performed on AZ31B-H24 sheet specimens along the normal direction of a 6.35 mm-thick sheet. Miniature specimens machined through thickness are tested using a novel setup designed for large strain reverse loading data generation where specimen size is limited. The reliability of the devised setup is verified by finite element simulation and by reproducing in-plane curves obtained via an anti-buckling fixture. A shot peening process involving prevailing through-thickness deformation is modeled and numerical results indicate that employing only in-plane properties of magnesium sheets for simulating such processes can lead to inaccurate predictions.
{"title":"A Novel Test Design for Large Strain Uniaxial Reverse Loading of AZ31B Sheet Out of the Rolling Plane","authors":"A. Yazdanmehr, Ali A. Roostaei, H. Jahed","doi":"10.1115/1.4050727","DOIUrl":"https://doi.org/10.1115/1.4050727","url":null,"abstract":"\u0000 Understanding a magnesium alloy sheet's response to load reversals is important to accurately simulate and optimize a component's manufacturing process. Through this research, the room temperature compression-tension and tension-compression experiments with strains up to ∼12% are performed on AZ31B-H24 sheet specimens along the normal direction of a 6.35 mm-thick sheet. Miniature specimens machined through thickness are tested using a novel setup designed for large strain reverse loading data generation where specimen size is limited. The reliability of the devised setup is verified by finite element simulation and by reproducing in-plane curves obtained via an anti-buckling fixture. A shot peening process involving prevailing through-thickness deformation is modeled and numerical results indicate that employing only in-plane properties of magnesium sheets for simulating such processes can lead to inaccurate predictions.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"47 1","pages":"1-14"},"PeriodicalIF":1.2,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87565406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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