The Experts below are selected from a list of 96 Experts worldwide ranked by ideXlab platform
Akihisa Inoue - One of the best experts on this subject based on the ideXlab platform.
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non equilibrium copper based Crystalline Alloy sheet having ultrahigh strength and good electrical conductivity
Journal of Alloys and Compounds, 2011Co-Authors: Haruko Miura, Nobuyuki Nishiyama, Akihisa InoueAbstract:Abstract To develop an alternative material to Cu–Be Alloys, Cu 93.5 Zr 5.5 Ag 1 non-equilibrium Alloy sheets were prepared through the simple production process of die-casting, annealing and cold rolling. The developed sheets exhibit ultrahigh tensile strength of 1530 MPa, plastic elongation of 1.2% and good electrical conductivity. These results suggest that the developed sheets have excellent properties and constitute an alternative material to Cu–Be Alloys.
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structure conductivity and mechanical properties of non equilibrium copper based Crystalline Alloy nano composites
Intermetallics, 2010Co-Authors: Haruko Miura, Nobuyuki Nishiyama, N Togashi, Minoru Nishida, Akihisa InoueAbstract:Abstract Beryllium copper (Cu–Be) Alloys exhibit well-balanced properties of strength, elongation and conductivity, and have been used as the conventional material of electrical contacting parts. However, improved materials with higher performances are strongly required for miniaturization of their parts and environmental issues of Be. Recently, an Alloy design on the basis of glass-forming rules has enabled the development of Cu–Zr–Ag Alloys with tensile strength of 1200 MPa, plastic elongation of 3.1% and electrical conductivity of 30.7% IACS in a thin strip form through the simple production process of casting, cold rolling and annealing. This paper intends to present microstructure and properties of the newly developed Alloys and discuss the possibility for applying to electrical contacting materials.
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mechanisms of high strain rate superplasticity of al 14 mass ni 14 mass mm misch metal Alloy produced from amorphous powder
Materials Transactions Jim, 1995Co-Authors: Kenji Higashi, Akihisa Inoue, Toshiji Mukai, A. Uoya, Tsuyoshi MasumotoAbstract:The deformation mechanisms of a fine grained Al-14 mass%Ni-14 mass%Mm [Mm = misch metal] Crystalline Alloy consolidated from its amorphous powders have been discussed from the mechanical data examined previously at strain-rates between 10 -3 and 100 s -1 at temperatures from 773 to 898 K. This Alloy exhibits superplasticity at unusually high strain rates of nearly 1 s -1 in the temperature range from 848 to 885 K, which is close to the measured melting point. By incorporation of the temperature dependence of grain size, threshold stress and shear modulus into the constitutive equation, the activation energy is found to be 158 kJ mol -1 at temperatures below the melting point. In the temperature range above the melting point, however, the activation energy is very large at more than 350 kJ mol -1 . This activation energy in the temperature range below the melting point is similar to that for lattice self-diffusion of aluminum, and all mechanical data in these temperatures ranges can be represented by a single equation. It is postulated that superplastic flow in the Al-Ni-Mm Crystalline Alloy is controlled by a grain boundary sliding mechanism accommodated by dislocation climb controlled by lattice self-diffusion at the solid state, and in the temperature range higher than the melting point is accommodated by the liquid phase at grain boundaries and/or interfaces. The further deformation mechanisms in high strain rate superplasticity should take the phase state of liquid and solid into account.
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high strain rate superplasticity in an alni misch metal Alloy produced from its amorphous powders
Scripta Metallurgica Et Materialia, 1992Co-Authors: Kenji Higashi, Akihisa Inoue, Toshiji Mukai, Shinji Tanimura, Tsuyoshi Masumoto, K. Ohtera, K Kita, J NagahoraAbstract:The detection is reported of high-strain-rate superplasticity in a new aluminum-based Crystalline Alloy, an as-extruded Al-Ni-Mm (Mm = misch) Alloy which was fabricated by warm consolidation of its amorphous powders and was developed to be a very fine-grained structure of 70 nm in size, with a very uniform distribution of both Al3Mm and Al3Ni particulates of 70 nm. The maximum elongation of 540 pct was recorded at 0.7 s and 873 K, at which a high m value of 0.5 was obtained. The superplastic strain rate for the Al-Ni-Mm Alloy was many orders of magnitude higher than that for typical superplastic Alloys. This result shows a new possibility for the development of high strain rate superplasticity in aluminum-based Alloys fabricated by warm consolidation of their amorphous powders. 7 refs.
W. L. Johnson - One of the best experts on this subject based on the ideXlab platform.
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a highly processable metallic glass zr sub 41 2 ti sub 13 8 cu sub 12 5 ni sub 10 0 be sub 22 5
Applied Physics Letters; (United States), 1993Co-Authors: Atakan Peker, W. L. JohnsonAbstract:We report on the properties of one example of a new family of metallic Alloys which exhibit excellent glass forming ability. The critical cooling rate to retain the glassy phase is of the order of 10 K/s or less. Large samples in the form of rods ranging up to 14 mm in diameter have been prepared by casting in silica containers. The undercooled liquid Alloy has been studied over a wide range of temperatures between the glass transition temperature and the thermodynamic melting point of the equilibrium Crystalline Alloy using scanning calorimetry. Crystallization of the material has been studied. Some characteristic properties of the new material are presented. The origins of exceptional glass forming ability of these new Alloys are discussed.
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A highly processable metallic glass: Zr41.2Ti13.8Cu12.5Ni10.0Be22.5
Applied Physics Letters, 1993Co-Authors: Atakan Peker, W. L. JohnsonAbstract:We report on the properties of one example of a new family of metallic Alloys which exhibit excellent glass forming ability. The critical cooling rate to retain the glassy phase is of the order of 10 K/s or less. Large samples in the form of rods ranging up to 14 mm in diameter have been prepared by casting in silica containers. The undercooled liquid Alloy has been studied over a wide range of temperatures between the glass transition temperature and the thermodynamic melting point of the equilibrium Crystalline Alloy using scanning calorimetry. Crystallization of the material has been studied. Some characteristic properties of the new material are presented. The origins of exceptional glass forming ability of these new Alloys are discussed.
Brunemeier, Paul Edward - One of the best experts on this subject based on the ideXlab platform.
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Liquid phase epitaxial growth and heterointerface characteristics of long-wavelength indium gallium arsenide phosphide heterostructures
1Co-Authors: Brunemeier, Paul EdwardAbstract:Data are presented that demonstrate that the InGaAsP quaternary grown by constant temperature liquid phase epitaxy on InP substrate can, under certain growth conditions, exhibit considerably narrower diffraction profile half-widths than previously reported. The double crystal x-ray diffraction half-width is a relatively new assay of Crystalline Alloy compositional homogeneity, and the 13 arc sec value presented here for InGaAsP may represent a lower limit for the homogeneity of this material system, as a result of Alloy effects. Bandgap and lattice constant data are given that characterize the transient composition that occurs at the onset of liquid phase epitaxial growth of InGaAsP on InP substrates. This compositional inhomogeneity, a region of significantly different bandgap and lattice constant than that of the remainder of the layer, is a result of the extreme non-equilibirum conditions that exist in the first milliseconds of growth. The data presented here indicate a shift in mismatch and bandgap of " 16xlO-4 and (20 meV t respectively, as a result of the transient composition. These results permit a calculation of the changes in the individual solidus atomic species, which illuminate some aspects of incorporation kinetic effects. Transmission electron microscopy (TEM) data are presented that characterize the interfacial "damage" that arises during the liquid phase epitaxial growth of an arsenic-poor InGaAsP quatenary on a previously grown iv arsenic-rich layer. This "damage" takes the form of a ragged heterointerface with extensive dislocations and is observed for Some of the heterostructures examined. Other heterostructures are demonstrated that yield high-quality interfaces in TEM, which is corroborated by their performance as roomtemperature lasers. Stimulated emission data for single-well quantum well heterostructures (QWH's) permit a direct measurement of the InGaAsP-lnP valence-band discontinuity (llEv). As the width of a single quantum well grows small, photogenerated electrons are poorly. collected, while the heavier-mass holes are efficiently collected. Recombination between "hot" electrons and bound holes produces radiation that is depressed from the InP bandgap energy by ~Ev' which is observed in the photoluminescence of single-well QWH's. The photoluminescence method is potentially the most direct and accurate measurement of heterojunction band discontinuities.U of I OnlyThesi
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Liquid Phase Epitaxial Growth and Heterointerface Characteristics of Long-Wavelength Indium - Gallium Arsenide - Phosphide Heterostructures (Lasers, Semiconductors)
1Co-Authors: Brunemeier, Paul EdwardAbstract:185 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1985.Data are presented that demonstrate that the InGaAsP quaternary grown by constant temperature liquid phase epitaxy on InP substrate can, under certain growth conditions, exhibit considerably narrower diffraction profile half-widths than previously reported. The double crystal x-ray diffraction half-width is a relatively new assay of Crystalline Alloy compositional homogeneity, and the 13 arc sec value presented here for InGaAsP may represent a lower limit for the homogeneity of this material system, as a result of Alloy effects.Bandgap and lattice constant data are given that characterize the transient composition that occurs at the onset of liquid phase epitaxial growth of InGaAsP on InP substrates. This compositional inhomogeneity, a region of significantly different bandgap and lattice constant than that of the remainder of the layer, is a result of the extreme non-equilibrium conditions that exist in the first milliseconds of growth. The data presented here indicate a shift in mismatch and bandgap of (LESSTHEQ) 16 x 10('-4) and (LESSTHEQ) 20 meV, respectively, as a result of the transient composition. These results permit a calculation of the changes in the individual solidus atomic species, which illuminate some aspects of incorporation kinetic effects.Transmission electron microscopy (TEM) data are presented that characterize the interfacial "damage" that arises during the liquid phase epitaxial growth of an arsenic-poor InGaAsP quatenary on a previously grown arsenic-rich layer. This "damage" takes the form of a ragged heterointerface with extensive dislocations and is observed for some of the heterostructures examined. Other heterostructures are demonstrated that yield high-quality interfaces in TEM, which is corroborated by their performance as room-temperature lasers.Stimulated emission data for single-well quantum well heterostructures (QWH's) permit a direct measurement of the InGaAsP-InP valence-band discontinuity ((DELTA)E(,v)). As the width of a single quantum well grows small, photogenerated electrons are poorly collected, while the heavier-mass holes are efficiently collected. Recombination between "hot" electrons and bound holes produces radiation that is depressed from the InP bandgap energy by (DELTA)E(,v), which is observed in the photoluminescence of single-well QWH's. The photoluminescence method is potentially the most direct and accurate measurement of heterojunction band discontinuities.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD
Atakan Peker - One of the best experts on this subject based on the ideXlab platform.
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a highly processable metallic glass zr sub 41 2 ti sub 13 8 cu sub 12 5 ni sub 10 0 be sub 22 5
Applied Physics Letters; (United States), 1993Co-Authors: Atakan Peker, W. L. JohnsonAbstract:We report on the properties of one example of a new family of metallic Alloys which exhibit excellent glass forming ability. The critical cooling rate to retain the glassy phase is of the order of 10 K/s or less. Large samples in the form of rods ranging up to 14 mm in diameter have been prepared by casting in silica containers. The undercooled liquid Alloy has been studied over a wide range of temperatures between the glass transition temperature and the thermodynamic melting point of the equilibrium Crystalline Alloy using scanning calorimetry. Crystallization of the material has been studied. Some characteristic properties of the new material are presented. The origins of exceptional glass forming ability of these new Alloys are discussed.
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A highly processable metallic glass: Zr41.2Ti13.8Cu12.5Ni10.0Be22.5
Applied Physics Letters, 1993Co-Authors: Atakan Peker, W. L. JohnsonAbstract:We report on the properties of one example of a new family of metallic Alloys which exhibit excellent glass forming ability. The critical cooling rate to retain the glassy phase is of the order of 10 K/s or less. Large samples in the form of rods ranging up to 14 mm in diameter have been prepared by casting in silica containers. The undercooled liquid Alloy has been studied over a wide range of temperatures between the glass transition temperature and the thermodynamic melting point of the equilibrium Crystalline Alloy using scanning calorimetry. Crystallization of the material has been studied. Some characteristic properties of the new material are presented. The origins of exceptional glass forming ability of these new Alloys are discussed.
Haruko Miura - One of the best experts on this subject based on the ideXlab platform.
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non equilibrium copper based Crystalline Alloy sheet having ultrahigh strength and good electrical conductivity
Journal of Alloys and Compounds, 2011Co-Authors: Haruko Miura, Nobuyuki Nishiyama, Akihisa InoueAbstract:Abstract To develop an alternative material to Cu–Be Alloys, Cu 93.5 Zr 5.5 Ag 1 non-equilibrium Alloy sheets were prepared through the simple production process of die-casting, annealing and cold rolling. The developed sheets exhibit ultrahigh tensile strength of 1530 MPa, plastic elongation of 1.2% and good electrical conductivity. These results suggest that the developed sheets have excellent properties and constitute an alternative material to Cu–Be Alloys.
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structure conductivity and mechanical properties of non equilibrium copper based Crystalline Alloy nano composites
Intermetallics, 2010Co-Authors: Haruko Miura, Nobuyuki Nishiyama, N Togashi, Minoru Nishida, Akihisa InoueAbstract:Abstract Beryllium copper (Cu–Be) Alloys exhibit well-balanced properties of strength, elongation and conductivity, and have been used as the conventional material of electrical contacting parts. However, improved materials with higher performances are strongly required for miniaturization of their parts and environmental issues of Be. Recently, an Alloy design on the basis of glass-forming rules has enabled the development of Cu–Zr–Ag Alloys with tensile strength of 1200 MPa, plastic elongation of 3.1% and electrical conductivity of 30.7% IACS in a thin strip form through the simple production process of casting, cold rolling and annealing. This paper intends to present microstructure and properties of the newly developed Alloys and discuss the possibility for applying to electrical contacting materials.