The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
G L Chen - One of the best experts on this subject based on the ideXlab platform.
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investigation of shear bands under Compressive Testing for zr base bulk metallic glasses containing nanocrystals
Scripta Materialia, 2002Co-Authors: Z Bian, G He, G L ChenAbstract:Granular flow of nickel particles down a vertical pipe from a hopper is shown to be retarded by a horizontal ac electric field applied to a local region along the pipe. The particles are released from the hopper by pulling out a stopper in the hopper. Two sequences of experiments with different initial flow conditions are performed. In the first sequence, a dilute flow in the pipe is created after a fixed voltage V (less than or equal to4.8 kV) is applied across two short, vertical copper electrodes. The steady-state flow rate Q remains practically constant for V V-1, the flow becomes dense; Q decreases with a power law, Qsimilar toV(-1). In the second sequence of experiments, V is first set at 4.8 kV; the flow is allowed to start, and soon becomes a dense flow; then, V is reduced to the desired voltage. The new, steady-state Q vs V curve coincides with the previous Q(V) curve of the first sequence, except for V-2 V-2) to a dilute flow (V
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microstructure and ductile brittle transition of as cast zr based bulk glass alloys under Compressive Testing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2001Co-Authors: Z Bian, G L Chen, G HeAbstract:Abstract This paper investigates mechanical properties and fracture mechanisms of Zr 52.5 Cu 17.9 Ni 14.6 Al 10 Ti 5 alloys with various volume fractions of quenched-in crystalline. The alloys with various volume fractions of quenched-in crystalline were prepared by controlled oxygen content of alloys and overheating of the pouring. The phase structure, particle size and volume fraction of all samples were identified by X-ray diffraction, differential scanning calorimeter (DSC) curves and scanning electron microscopy (SEM) photographs. The mean sizes of crystalline increased from 0.3 to 1.3 μm with increasing volume fraction of crystalline from 4 to 13%. The Compressive mechanical tests show a ductile–brittle transition with significant decrease in the fracture stress and ductility. Detailed observations in the flow deformation and fracture surface illustrate the relationship between the quenching-in crystalline and the mechanical behavior. The full bulk amorphous Zr-based alloy exhibits typical ductile deformation and fracture behavior. The torn shear bands form the typical vein patterns on the fracture surface. The effects of quenching-in crystalline on the flow deformation and fracture behavior depend on the nature, size, volume fraction and distribution. The particle size of the crystalline in the sense of the width of shear bands is critical. When the size is larger than the width of the shear bands the particles induce an obvious inhomogeneity of the flow deformation and more microcracks by the separation of the interfaces. Nano-scale particles, on the other hand, may increase the viscosity of the flow but do not form microcracks, resulting in particle strengthening of the metallic glass. Increasing the volume fraction of large-scale particles is favorable to leaking the microcracks and brittle fracture. With increasing particle size and volume fraction up to two times the width of the shear band and 10% vol., respectively, the ductile fracture of bulk amorphous alloy completely transforms to brittle fracture under Compressive Testing.
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Microstructure and ductile–brittle transition of as-cast Zr-based bulk glass alloys under Compressive Testing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2001Co-Authors: Z Bian, G L Chen, G HeAbstract:Abstract This paper investigates mechanical properties and fracture mechanisms of Zr 52.5 Cu 17.9 Ni 14.6 Al 10 Ti 5 alloys with various volume fractions of quenched-in crystalline. The alloys with various volume fractions of quenched-in crystalline were prepared by controlled oxygen content of alloys and overheating of the pouring. The phase structure, particle size and volume fraction of all samples were identified by X-ray diffraction, differential scanning calorimeter (DSC) curves and scanning electron microscopy (SEM) photographs. The mean sizes of crystalline increased from 0.3 to 1.3 μm with increasing volume fraction of crystalline from 4 to 13%. The Compressive mechanical tests show a ductile–brittle transition with significant decrease in the fracture stress and ductility. Detailed observations in the flow deformation and fracture surface illustrate the relationship between the quenching-in crystalline and the mechanical behavior. The full bulk amorphous Zr-based alloy exhibits typical ductile deformation and fracture behavior. The torn shear bands form the typical vein patterns on the fracture surface. The effects of quenching-in crystalline on the flow deformation and fracture behavior depend on the nature, size, volume fraction and distribution. The particle size of the crystalline in the sense of the width of shear bands is critical. When the size is larger than the width of the shear bands the particles induce an obvious inhomogeneity of the flow deformation and more microcracks by the separation of the interfaces. Nano-scale particles, on the other hand, may increase the viscosity of the flow but do not form microcracks, resulting in particle strengthening of the metallic glass. Increasing the volume fraction of large-scale particles is favorable to leaking the microcracks and brittle fracture. With increasing particle size and volume fraction up to two times the width of the shear band and 10% vol., respectively, the ductile fracture of bulk amorphous alloy completely transforms to brittle fracture under Compressive Testing.
G He - One of the best experts on this subject based on the ideXlab platform.
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investigation of shear bands under Compressive Testing for zr base bulk metallic glasses containing nanocrystals
Scripta Materialia, 2002Co-Authors: Z Bian, G He, G L ChenAbstract:Granular flow of nickel particles down a vertical pipe from a hopper is shown to be retarded by a horizontal ac electric field applied to a local region along the pipe. The particles are released from the hopper by pulling out a stopper in the hopper. Two sequences of experiments with different initial flow conditions are performed. In the first sequence, a dilute flow in the pipe is created after a fixed voltage V (less than or equal to4.8 kV) is applied across two short, vertical copper electrodes. The steady-state flow rate Q remains practically constant for V V-1, the flow becomes dense; Q decreases with a power law, Qsimilar toV(-1). In the second sequence of experiments, V is first set at 4.8 kV; the flow is allowed to start, and soon becomes a dense flow; then, V is reduced to the desired voltage. The new, steady-state Q vs V curve coincides with the previous Q(V) curve of the first sequence, except for V-2 V-2) to a dilute flow (V
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microstructure and ductile brittle transition of as cast zr based bulk glass alloys under Compressive Testing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2001Co-Authors: Z Bian, G L Chen, G HeAbstract:Abstract This paper investigates mechanical properties and fracture mechanisms of Zr 52.5 Cu 17.9 Ni 14.6 Al 10 Ti 5 alloys with various volume fractions of quenched-in crystalline. The alloys with various volume fractions of quenched-in crystalline were prepared by controlled oxygen content of alloys and overheating of the pouring. The phase structure, particle size and volume fraction of all samples were identified by X-ray diffraction, differential scanning calorimeter (DSC) curves and scanning electron microscopy (SEM) photographs. The mean sizes of crystalline increased from 0.3 to 1.3 μm with increasing volume fraction of crystalline from 4 to 13%. The Compressive mechanical tests show a ductile–brittle transition with significant decrease in the fracture stress and ductility. Detailed observations in the flow deformation and fracture surface illustrate the relationship between the quenching-in crystalline and the mechanical behavior. The full bulk amorphous Zr-based alloy exhibits typical ductile deformation and fracture behavior. The torn shear bands form the typical vein patterns on the fracture surface. The effects of quenching-in crystalline on the flow deformation and fracture behavior depend on the nature, size, volume fraction and distribution. The particle size of the crystalline in the sense of the width of shear bands is critical. When the size is larger than the width of the shear bands the particles induce an obvious inhomogeneity of the flow deformation and more microcracks by the separation of the interfaces. Nano-scale particles, on the other hand, may increase the viscosity of the flow but do not form microcracks, resulting in particle strengthening of the metallic glass. Increasing the volume fraction of large-scale particles is favorable to leaking the microcracks and brittle fracture. With increasing particle size and volume fraction up to two times the width of the shear band and 10% vol., respectively, the ductile fracture of bulk amorphous alloy completely transforms to brittle fracture under Compressive Testing.
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Microstructure and ductile–brittle transition of as-cast Zr-based bulk glass alloys under Compressive Testing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2001Co-Authors: Z Bian, G L Chen, G HeAbstract:Abstract This paper investigates mechanical properties and fracture mechanisms of Zr 52.5 Cu 17.9 Ni 14.6 Al 10 Ti 5 alloys with various volume fractions of quenched-in crystalline. The alloys with various volume fractions of quenched-in crystalline were prepared by controlled oxygen content of alloys and overheating of the pouring. The phase structure, particle size and volume fraction of all samples were identified by X-ray diffraction, differential scanning calorimeter (DSC) curves and scanning electron microscopy (SEM) photographs. The mean sizes of crystalline increased from 0.3 to 1.3 μm with increasing volume fraction of crystalline from 4 to 13%. The Compressive mechanical tests show a ductile–brittle transition with significant decrease in the fracture stress and ductility. Detailed observations in the flow deformation and fracture surface illustrate the relationship between the quenching-in crystalline and the mechanical behavior. The full bulk amorphous Zr-based alloy exhibits typical ductile deformation and fracture behavior. The torn shear bands form the typical vein patterns on the fracture surface. The effects of quenching-in crystalline on the flow deformation and fracture behavior depend on the nature, size, volume fraction and distribution. The particle size of the crystalline in the sense of the width of shear bands is critical. When the size is larger than the width of the shear bands the particles induce an obvious inhomogeneity of the flow deformation and more microcracks by the separation of the interfaces. Nano-scale particles, on the other hand, may increase the viscosity of the flow but do not form microcracks, resulting in particle strengthening of the metallic glass. Increasing the volume fraction of large-scale particles is favorable to leaking the microcracks and brittle fracture. With increasing particle size and volume fraction up to two times the width of the shear band and 10% vol., respectively, the ductile fracture of bulk amorphous alloy completely transforms to brittle fracture under Compressive Testing.
Z Bian - One of the best experts on this subject based on the ideXlab platform.
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investigation of shear bands under Compressive Testing for zr base bulk metallic glasses containing nanocrystals
Scripta Materialia, 2002Co-Authors: Z Bian, G He, G L ChenAbstract:Granular flow of nickel particles down a vertical pipe from a hopper is shown to be retarded by a horizontal ac electric field applied to a local region along the pipe. The particles are released from the hopper by pulling out a stopper in the hopper. Two sequences of experiments with different initial flow conditions are performed. In the first sequence, a dilute flow in the pipe is created after a fixed voltage V (less than or equal to4.8 kV) is applied across two short, vertical copper electrodes. The steady-state flow rate Q remains practically constant for V V-1, the flow becomes dense; Q decreases with a power law, Qsimilar toV(-1). In the second sequence of experiments, V is first set at 4.8 kV; the flow is allowed to start, and soon becomes a dense flow; then, V is reduced to the desired voltage. The new, steady-state Q vs V curve coincides with the previous Q(V) curve of the first sequence, except for V-2 V-2) to a dilute flow (V
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microstructure and ductile brittle transition of as cast zr based bulk glass alloys under Compressive Testing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2001Co-Authors: Z Bian, G L Chen, G HeAbstract:Abstract This paper investigates mechanical properties and fracture mechanisms of Zr 52.5 Cu 17.9 Ni 14.6 Al 10 Ti 5 alloys with various volume fractions of quenched-in crystalline. The alloys with various volume fractions of quenched-in crystalline were prepared by controlled oxygen content of alloys and overheating of the pouring. The phase structure, particle size and volume fraction of all samples were identified by X-ray diffraction, differential scanning calorimeter (DSC) curves and scanning electron microscopy (SEM) photographs. The mean sizes of crystalline increased from 0.3 to 1.3 μm with increasing volume fraction of crystalline from 4 to 13%. The Compressive mechanical tests show a ductile–brittle transition with significant decrease in the fracture stress and ductility. Detailed observations in the flow deformation and fracture surface illustrate the relationship between the quenching-in crystalline and the mechanical behavior. The full bulk amorphous Zr-based alloy exhibits typical ductile deformation and fracture behavior. The torn shear bands form the typical vein patterns on the fracture surface. The effects of quenching-in crystalline on the flow deformation and fracture behavior depend on the nature, size, volume fraction and distribution. The particle size of the crystalline in the sense of the width of shear bands is critical. When the size is larger than the width of the shear bands the particles induce an obvious inhomogeneity of the flow deformation and more microcracks by the separation of the interfaces. Nano-scale particles, on the other hand, may increase the viscosity of the flow but do not form microcracks, resulting in particle strengthening of the metallic glass. Increasing the volume fraction of large-scale particles is favorable to leaking the microcracks and brittle fracture. With increasing particle size and volume fraction up to two times the width of the shear band and 10% vol., respectively, the ductile fracture of bulk amorphous alloy completely transforms to brittle fracture under Compressive Testing.
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Microstructure and ductile–brittle transition of as-cast Zr-based bulk glass alloys under Compressive Testing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2001Co-Authors: Z Bian, G L Chen, G HeAbstract:Abstract This paper investigates mechanical properties and fracture mechanisms of Zr 52.5 Cu 17.9 Ni 14.6 Al 10 Ti 5 alloys with various volume fractions of quenched-in crystalline. The alloys with various volume fractions of quenched-in crystalline were prepared by controlled oxygen content of alloys and overheating of the pouring. The phase structure, particle size and volume fraction of all samples were identified by X-ray diffraction, differential scanning calorimeter (DSC) curves and scanning electron microscopy (SEM) photographs. The mean sizes of crystalline increased from 0.3 to 1.3 μm with increasing volume fraction of crystalline from 4 to 13%. The Compressive mechanical tests show a ductile–brittle transition with significant decrease in the fracture stress and ductility. Detailed observations in the flow deformation and fracture surface illustrate the relationship between the quenching-in crystalline and the mechanical behavior. The full bulk amorphous Zr-based alloy exhibits typical ductile deformation and fracture behavior. The torn shear bands form the typical vein patterns on the fracture surface. The effects of quenching-in crystalline on the flow deformation and fracture behavior depend on the nature, size, volume fraction and distribution. The particle size of the crystalline in the sense of the width of shear bands is critical. When the size is larger than the width of the shear bands the particles induce an obvious inhomogeneity of the flow deformation and more microcracks by the separation of the interfaces. Nano-scale particles, on the other hand, may increase the viscosity of the flow but do not form microcracks, resulting in particle strengthening of the metallic glass. Increasing the volume fraction of large-scale particles is favorable to leaking the microcracks and brittle fracture. With increasing particle size and volume fraction up to two times the width of the shear band and 10% vol., respectively, the ductile fracture of bulk amorphous alloy completely transforms to brittle fracture under Compressive Testing.
Akihisa Inoue - One of the best experts on this subject based on the ideXlab platform.
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Carbon-nanotube-reinforced Zr-based bulk metallic glass composites and their properties
Advanced Functional Materials, 2004Co-Authors: Zan Bian, Ru Ju Wang, Wei-hua Wang, Tao Zhang, Akihisa InoueAbstract:In this paper, we systematically report the preparation of carbon-nanotube (CNT)-reinforced Zr-based bulk metallic glass (BMG) composites. The physical and mechanical properties of the composites were investigated. Compressive Testing shows that the composites still display high fracture strength. Investigation also shows that the composites have strong ultrasonic attenuation characteristics and excellent wave absorption ability. The strong wave absorption implies that CNT-reinforced Zr-based BMG composites, besides their excellent mechanical properties, may also have significant potential for applications in shielding acoustic sound or environmental noise.
Gergely Czel - One of the best experts on this subject based on the ideXlab platform.
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hybrid specimens eliminating stress concentrations in tensile and Compressive Testing of unidirectional composites
Composites Part A-applied Science and Manufacturing, 2016Co-Authors: Gergely Czel, Meisam Jalalvand, Michael R WisnomAbstract:Two novel approaches are proposed for elimination of stress concentrations in tensile and Compressive Testing of unidirectional carbon/epoxy composites. An interlayer hybrid specimen type is proposed for tensile Testing. The presented finite element study indicated that the outer continuous glass/epoxy plies suppress the stress concentrations at the grips and protect the central carbon/epoxy plies from premature failure, eliminating the need for end-tabs. The test results confirmed the benefits of the hybrid specimens by generating consistent gauge-section failures in tension. The developed hybrid four point bending specimen type and strain evaluation method were verified and applied successfully to determine the Compressive failure strain of three different grade carbon/epoxy composite prepregs. Stable failure and fragmentation of the high and ultra-high modulus unidirectional carbon/epoxy plies were reported. The high strength carbon/epoxy plies exhibited catastrophic failure at a significantly higher Compressive strain than normally observed.
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Hybrid specimens eliminating stress concentrations in tensile and Compressive Testing of unidirectional composites Part A Applied science and manufacturing
Composites, 2016Co-Authors: Gergely Czel, Meisam Jalalvand, Michael R WisnomAbstract:Two novel approaches are proposed for elimination of stress concentrations in tensile and Compressive Testing of unidirectional carbon/epoxy composites. An interlayer hybrid specimen type is proposed for tensile Testing. The presented finite element study indicated that the outer continuous glass/epoxy plies suppress the stress concentrations at the grips and protect the central carbon/epoxy plies from premature failure, eliminating the need for end-tabs. The test results confirmed the benefits of the hybrid specimens by generating consistent gauge-section failures in tension. The developed hybrid four point bending specimen type and strain evaluation method were verified and applied successfully to determine the Compressive failure strain of three different grade carbon/epoxy composite prepregs. Stable failure and fragmentation of the high and ultra-high modulus unidirectional carbon/epoxy plies were reported. The high strength carbon/epoxy plies exhibited catastrophic failure at a significantly higher Compressive strain than normally observed.