Roy Arrowood - Academia.edu (original) (raw)
Papers by Roy Arrowood
Journal of Materials Science - J MATER SCI, 2001
Copper clusters, as nodules and micro dendritic masses, were observed to nucleate and grow on Al ... more Copper clusters, as nodules and micro dendritic masses, were observed to nucleate and grow on Al 2524 surfaces after corrosion immersion experiments for up to 5 days in 0.6 M NaCl solutions; with pH values ranging from 3 to 11. Cu clusters observed by SEM on the corroded surfaces and confirmed by EDX analysis were extracted or stripped from their original sites and examined in detail utilizing TEM and EDX spectrometry. These observations confirm a mechanism contributing to pitting corrosion in copper-rich aluminum alloys involving the plating or cementation of Cu2+ from solution as an electrochemical displacement reaction, resulting in nucleation and growth of Cu clusters on the aluminum alloy surface, and causing additional aluminum dissolution and pitting around the Cu deposits.
Journal of Materials Science - J MATER SCI, 2001
Copper clusters, as nodules and micro dendritic masses, were observed to nucleate and grow on Al ... more Copper clusters, as nodules and micro dendritic masses, were observed to nucleate and grow on Al 2524 surfaces after corrosion immersion experiments for up to 5 days in 0.6 M NaCl solutions; with pH values ranging from 3 to 11. Cu clusters observed by SEM on the corroded surfaces and confirmed by EDX analysis were extracted or stripped from their original sites and examined in detail utilizing TEM and EDX spectrometry. These observations confirm a mechanism contributing to pitting corrosion in copper-rich aluminum alloys involving the plating or cementation of Cu2+ from solution as an electrochemical displacement reaction, resulting in nucleation and growth of Cu clusters on the aluminum alloy surface, and causing additional aluminum dissolution and pitting around the Cu deposits.
Materials Science and Engineering, 1987
ABSTRACT The deformation kinetics of fine-grained (4.6 μm) samples of Sn-38.1wt.%Pb at 313 K disp... more ABSTRACT The deformation kinetics of fine-grained (4.6 μm) samples of Sn-38.1wt.%Pb at 313 K displayed a sigmoidal stress dependence. Below 0.6 MPa (region I) the stress exponent n was 3.1; between 0.6 and 10 MPa (region II), n was 1.6; above 10 MPa (region III), n was 3.0. The activation energy of region II creep was 49 kJ mol−1, which compares with that of diffusion along grain boundaries or interphase boundaries. In region II the grain size exponent of the steady creep rate was 3.0. A decelerating primary stage of creep occurred in region I and in much of region II.
... Ferregut • Dr. Roy Arrowood • Dr. Soheil Nazarian ADVISORY COMMITTEE • Dr. Yoseph Bar-Cohen, ... more ... Ferregut • Dr. Roy Arrowood • Dr. Soheil Nazarian ADVISORY COMMITTEE • Dr. Yoseph Bar-Cohen, JPL/Caltech • Dr. Dale Chimenti, Iowa State ... S. Choi 23 Damage Detection Methods Based on Wavelet Analyses of Sensor Signals X. Deng, Q. Wang, CA Rogers, V. Giurgiutiu ...
... Ferregut • Dr. Roy Arrowood • Dr. Soheil Nazarian ADVISORY COMMITTEE • Dr. Yoseph Bar-Cohen, ... more ... Ferregut • Dr. Roy Arrowood • Dr. Soheil Nazarian ADVISORY COMMITTEE • Dr. Yoseph Bar-Cohen, JPL/Caltech • Dr. Dale Chimenti, Iowa State ... S. Choi 23 Damage Detection Methods Based on Wavelet Analyses of Sensor Signals X. Deng, Q. Wang, CA Rogers, V. Giurgiutiu ...
Journal of Materials Science, 2000
Copper and copper-rich particle clusters were observed to deposit on aging aircraft skin material... more Copper and copper-rich particle clusters were observed to deposit on aging aircraft skin material (Al 2024 sheet coupons) after corrosion immersion experiments for 5 days in acidic (pH 3) neutral (pH ~ 6), and basic (pH 11) 0.6 M NaCl solutions. SEM analysis employing an EDX spectrometer showed a propensity of large Cu particle clusters on Fe-rich or Fe-containing areas
This report summarizes the results of research into the areas of the fragmentation and entrainmen... more This report summarizes the results of research into the areas of the fragmentation and entrainment of airborne respirable dust (ARD). The objectives of the program were fourfold: first, to review the present state of knowledge regarding ARD; second, to expand this state of knowledge through the identification of hypothetical microscopic mechanisms by which the coal is fragmented and the dust
Scripta Metallurgica, 1984
Abstract: This report summarizes the results of a three-phase study of (1) fatigue crack growth a... more Abstract: This report summarizes the results of a three-phase study of (1) fatigue crack growth and load interaction modeling in aluminum alloys,(2) the effect of microstructure on susceptibility to hydrogen embrittlement in titanium alloys, and (3) micromechanisms of ...
This report summarizes the results of research into the areas of the fragmentation and entrainmen... more This report summarizes the results of research into the areas of the fragmentation and entrainment of airborne respirable dust (ARD). The objectives of this program were fourfold: first, to review the present state of knowledge regarding ARD; second, to expand this state of knowledge through the identification of hypothetical microscopic mechanisms by which the coal is fragmented and the dust becomes entrained; third, to specify the informational requirements to verify or nullify these hypotheses; and fourth, to relate experimental techniques that will produce that required information. Volume II contains the appendix.
Materials Characterization, 1997
Exfoliation, a directional attack along elongated grain boundaries, has been examined in some det... more Exfoliation, a directional attack along elongated grain boundaries, has been examined in some detail in rolled 2024 aluminum sheet and plate for KC-135 aging aircraft body skin samples utilizing optical (light) metallography, scanning electron microscopy, and transmission electron microscopy. A detailed analysis and comparison of precipitates within the grains and in the grain boundaries were performed, as well as an examination of elemental depletion profiles across grain boundaries. These observations suggest that corrosion-related anodic sites play a far less significant role in the propagation of exfoliation than do the hard corrosion products creating wedging stresses within the elongated grain boundaries, which seem to demonstrate unique and unusual structural or energetic features or both. 0 Elsevier Science Inc.
Materials Science and Engineering, 1987
ABSTRACT The deformation kinetics of fine-grained (4.6 μm) samples of Sn-38.1wt.%Pb at 313 K disp... more ABSTRACT The deformation kinetics of fine-grained (4.6 μm) samples of Sn-38.1wt.%Pb at 313 K displayed a sigmoidal stress dependence. Below 0.6 MPa (region I) the stress exponent n was 3.1; between 0.6 and 10 MPa (region II), n was 1.6; above 10 MPa (region III), n was 3.0. The activation energy of region II creep was 49 kJ mol−1, which compares with that of diffusion along grain boundaries or interphase boundaries. In region II the grain size exponent of the steady creep rate was 3.0. A decelerating primary stage of creep occurred in region I and in much of region II.
Materials Science and Engineering, 1987
ABSTRACT Stress relaxation experiments on fine-grained samples of the SnPb eutectic alloy exhibi... more ABSTRACT Stress relaxation experiments on fine-grained samples of the SnPb eutectic alloy exhibit precipitous decreases in strain rate at nearly constant stress. However, comparison with creep results on the same material demonstrates that this behavior does not reflect any threshold stress for creep deformation. The relaxation behavior is well described by a mechanical analog model which incorporates an anelastic element similar to reported “superanelasticity” in this alloy. Creep of this material at a low stress can be described by a power law, with the strain rate proportional to the third power of stress, or by the influence of a threshold stress about an order of magnitude smaller than the false threshold of the stress relaxation experiments.
Strength of Metals and Alloys, 1979
Review of Scientific Instruments, 1980
A suitably shaped cam lever permits creep testing of polycrystals under constant stress rather th... more A suitably shaped cam lever permits creep testing of polycrystals under constant stress rather than constant load. The usual procedure for designing the cam lever is a graphical method, or an equivalent computational scheme. This paper derives simple analytical formulas for the cam lever shape.
Journal of Materials Science, 1987
At atmospheric pressure, a commercial 85% alumina fails by granulation, breaking into small flake... more At atmospheric pressure, a commercial 85% alumina fails by granulation, breaking into small flakes and splinters with long dimensions parallel to the load axis. Replica transmission elec-tron microscopy examination of polished surfaces on specimens loaded to 89% (or ...
Journal of Materials Science, 2001
Copper clusters, as nodules and micro dendritic masses, were observed to nucleate and grow on Al ... more Copper clusters, as nodules and micro dendritic masses, were observed to nucleate and grow on Al 2524 surfaces after corrosion immersion experiments for up to 5 days in 0.6 M NaCl solutions; with pH values ranging from 3 to 11. Cu clusters observed by SEM on the corroded surfaces and confirmed by EDX analysis were extracted or stripped from their
Bioinorganic Chemistry and Applications, 2012
The interaction of thioindigo and the phyllosilicate clay sepiolite is investigated using density... more The interaction of thioindigo and the phyllosilicate clay sepiolite is investigated using density functional theory (DFT) and molecular orbital theory (MO). The best fit to experimental UV/Vis spectra occurs when a single thioindigo molecule attaches via Van der Waals forces to a tetrahedrally coordinated Al 3+ cation with an additional nearby tetrahedrally coordinated Al 3+ also present. The thioindigo molecule distorts from its planar structure, a behavior consistent with a color change. Due to the weak interaction between thioindigo and sepiolite we conclude that the thioindigo molecule must be trapped in a channel, an observation consistent with previous experimental studies. Future computational studies will look at the interaction of indigo with sepiolite.
Advanced Performance Materials, 1998
Multiple plastic compositions containing polyethylene, polystyrene, PVC, ABS, Nylon, polypropylen... more Multiple plastic compositions containing polyethylene, polystyrene, PVC, ABS, Nylon, polypropylene, with various particle morphologies and a narrow range of sizes and size distributions were mixed with similar size brown glass into "glastic" composites having glass compositions of 15, 30, and 45 wt%. These prototypes were molded in a form similar to standard clay bricks at 235 • C and were compression tested to more than double the fracture stress of clay bricks at temperatures ranging from 20 to 50 • C. These prototypes illustrate the prospects for utilizing waste plastics and glass in simple commercial materials applications and the relief of land fill problems which are now world-wide.
Journal of Materials Science - J MATER SCI, 2001
Copper clusters, as nodules and micro dendritic masses, were observed to nucleate and grow on Al ... more Copper clusters, as nodules and micro dendritic masses, were observed to nucleate and grow on Al 2524 surfaces after corrosion immersion experiments for up to 5 days in 0.6 M NaCl solutions; with pH values ranging from 3 to 11. Cu clusters observed by SEM on the corroded surfaces and confirmed by EDX analysis were extracted or stripped from their original sites and examined in detail utilizing TEM and EDX spectrometry. These observations confirm a mechanism contributing to pitting corrosion in copper-rich aluminum alloys involving the plating or cementation of Cu2+ from solution as an electrochemical displacement reaction, resulting in nucleation and growth of Cu clusters on the aluminum alloy surface, and causing additional aluminum dissolution and pitting around the Cu deposits.
Journal of Materials Science - J MATER SCI, 2001
Copper clusters, as nodules and micro dendritic masses, were observed to nucleate and grow on Al ... more Copper clusters, as nodules and micro dendritic masses, were observed to nucleate and grow on Al 2524 surfaces after corrosion immersion experiments for up to 5 days in 0.6 M NaCl solutions; with pH values ranging from 3 to 11. Cu clusters observed by SEM on the corroded surfaces and confirmed by EDX analysis were extracted or stripped from their original sites and examined in detail utilizing TEM and EDX spectrometry. These observations confirm a mechanism contributing to pitting corrosion in copper-rich aluminum alloys involving the plating or cementation of Cu2+ from solution as an electrochemical displacement reaction, resulting in nucleation and growth of Cu clusters on the aluminum alloy surface, and causing additional aluminum dissolution and pitting around the Cu deposits.
Materials Science and Engineering, 1987
ABSTRACT The deformation kinetics of fine-grained (4.6 μm) samples of Sn-38.1wt.%Pb at 313 K disp... more ABSTRACT The deformation kinetics of fine-grained (4.6 μm) samples of Sn-38.1wt.%Pb at 313 K displayed a sigmoidal stress dependence. Below 0.6 MPa (region I) the stress exponent n was 3.1; between 0.6 and 10 MPa (region II), n was 1.6; above 10 MPa (region III), n was 3.0. The activation energy of region II creep was 49 kJ mol−1, which compares with that of diffusion along grain boundaries or interphase boundaries. In region II the grain size exponent of the steady creep rate was 3.0. A decelerating primary stage of creep occurred in region I and in much of region II.
... Ferregut • Dr. Roy Arrowood • Dr. Soheil Nazarian ADVISORY COMMITTEE • Dr. Yoseph Bar-Cohen, ... more ... Ferregut • Dr. Roy Arrowood • Dr. Soheil Nazarian ADVISORY COMMITTEE • Dr. Yoseph Bar-Cohen, JPL/Caltech • Dr. Dale Chimenti, Iowa State ... S. Choi 23 Damage Detection Methods Based on Wavelet Analyses of Sensor Signals X. Deng, Q. Wang, CA Rogers, V. Giurgiutiu ...
... Ferregut • Dr. Roy Arrowood • Dr. Soheil Nazarian ADVISORY COMMITTEE • Dr. Yoseph Bar-Cohen, ... more ... Ferregut • Dr. Roy Arrowood • Dr. Soheil Nazarian ADVISORY COMMITTEE • Dr. Yoseph Bar-Cohen, JPL/Caltech • Dr. Dale Chimenti, Iowa State ... S. Choi 23 Damage Detection Methods Based on Wavelet Analyses of Sensor Signals X. Deng, Q. Wang, CA Rogers, V. Giurgiutiu ...
Journal of Materials Science, 2000
Copper and copper-rich particle clusters were observed to deposit on aging aircraft skin material... more Copper and copper-rich particle clusters were observed to deposit on aging aircraft skin material (Al 2024 sheet coupons) after corrosion immersion experiments for 5 days in acidic (pH 3) neutral (pH ~ 6), and basic (pH 11) 0.6 M NaCl solutions. SEM analysis employing an EDX spectrometer showed a propensity of large Cu particle clusters on Fe-rich or Fe-containing areas
This report summarizes the results of research into the areas of the fragmentation and entrainmen... more This report summarizes the results of research into the areas of the fragmentation and entrainment of airborne respirable dust (ARD). The objectives of the program were fourfold: first, to review the present state of knowledge regarding ARD; second, to expand this state of knowledge through the identification of hypothetical microscopic mechanisms by which the coal is fragmented and the dust
Scripta Metallurgica, 1984
Abstract: This report summarizes the results of a three-phase study of (1) fatigue crack growth a... more Abstract: This report summarizes the results of a three-phase study of (1) fatigue crack growth and load interaction modeling in aluminum alloys,(2) the effect of microstructure on susceptibility to hydrogen embrittlement in titanium alloys, and (3) micromechanisms of ...
This report summarizes the results of research into the areas of the fragmentation and entrainmen... more This report summarizes the results of research into the areas of the fragmentation and entrainment of airborne respirable dust (ARD). The objectives of this program were fourfold: first, to review the present state of knowledge regarding ARD; second, to expand this state of knowledge through the identification of hypothetical microscopic mechanisms by which the coal is fragmented and the dust becomes entrained; third, to specify the informational requirements to verify or nullify these hypotheses; and fourth, to relate experimental techniques that will produce that required information. Volume II contains the appendix.
Materials Characterization, 1997
Exfoliation, a directional attack along elongated grain boundaries, has been examined in some det... more Exfoliation, a directional attack along elongated grain boundaries, has been examined in some detail in rolled 2024 aluminum sheet and plate for KC-135 aging aircraft body skin samples utilizing optical (light) metallography, scanning electron microscopy, and transmission electron microscopy. A detailed analysis and comparison of precipitates within the grains and in the grain boundaries were performed, as well as an examination of elemental depletion profiles across grain boundaries. These observations suggest that corrosion-related anodic sites play a far less significant role in the propagation of exfoliation than do the hard corrosion products creating wedging stresses within the elongated grain boundaries, which seem to demonstrate unique and unusual structural or energetic features or both. 0 Elsevier Science Inc.
Materials Science and Engineering, 1987
ABSTRACT The deformation kinetics of fine-grained (4.6 μm) samples of Sn-38.1wt.%Pb at 313 K disp... more ABSTRACT The deformation kinetics of fine-grained (4.6 μm) samples of Sn-38.1wt.%Pb at 313 K displayed a sigmoidal stress dependence. Below 0.6 MPa (region I) the stress exponent n was 3.1; between 0.6 and 10 MPa (region II), n was 1.6; above 10 MPa (region III), n was 3.0. The activation energy of region II creep was 49 kJ mol−1, which compares with that of diffusion along grain boundaries or interphase boundaries. In region II the grain size exponent of the steady creep rate was 3.0. A decelerating primary stage of creep occurred in region I and in much of region II.
Materials Science and Engineering, 1987
ABSTRACT Stress relaxation experiments on fine-grained samples of the SnPb eutectic alloy exhibi... more ABSTRACT Stress relaxation experiments on fine-grained samples of the SnPb eutectic alloy exhibit precipitous decreases in strain rate at nearly constant stress. However, comparison with creep results on the same material demonstrates that this behavior does not reflect any threshold stress for creep deformation. The relaxation behavior is well described by a mechanical analog model which incorporates an anelastic element similar to reported “superanelasticity” in this alloy. Creep of this material at a low stress can be described by a power law, with the strain rate proportional to the third power of stress, or by the influence of a threshold stress about an order of magnitude smaller than the false threshold of the stress relaxation experiments.
Strength of Metals and Alloys, 1979
Review of Scientific Instruments, 1980
A suitably shaped cam lever permits creep testing of polycrystals under constant stress rather th... more A suitably shaped cam lever permits creep testing of polycrystals under constant stress rather than constant load. The usual procedure for designing the cam lever is a graphical method, or an equivalent computational scheme. This paper derives simple analytical formulas for the cam lever shape.
Journal of Materials Science, 1987
At atmospheric pressure, a commercial 85% alumina fails by granulation, breaking into small flake... more At atmospheric pressure, a commercial 85% alumina fails by granulation, breaking into small flakes and splinters with long dimensions parallel to the load axis. Replica transmission elec-tron microscopy examination of polished surfaces on specimens loaded to 89% (or ...
Journal of Materials Science, 2001
Copper clusters, as nodules and micro dendritic masses, were observed to nucleate and grow on Al ... more Copper clusters, as nodules and micro dendritic masses, were observed to nucleate and grow on Al 2524 surfaces after corrosion immersion experiments for up to 5 days in 0.6 M NaCl solutions; with pH values ranging from 3 to 11. Cu clusters observed by SEM on the corroded surfaces and confirmed by EDX analysis were extracted or stripped from their
Bioinorganic Chemistry and Applications, 2012
The interaction of thioindigo and the phyllosilicate clay sepiolite is investigated using density... more The interaction of thioindigo and the phyllosilicate clay sepiolite is investigated using density functional theory (DFT) and molecular orbital theory (MO). The best fit to experimental UV/Vis spectra occurs when a single thioindigo molecule attaches via Van der Waals forces to a tetrahedrally coordinated Al 3+ cation with an additional nearby tetrahedrally coordinated Al 3+ also present. The thioindigo molecule distorts from its planar structure, a behavior consistent with a color change. Due to the weak interaction between thioindigo and sepiolite we conclude that the thioindigo molecule must be trapped in a channel, an observation consistent with previous experimental studies. Future computational studies will look at the interaction of indigo with sepiolite.
Advanced Performance Materials, 1998
Multiple plastic compositions containing polyethylene, polystyrene, PVC, ABS, Nylon, polypropylen... more Multiple plastic compositions containing polyethylene, polystyrene, PVC, ABS, Nylon, polypropylene, with various particle morphologies and a narrow range of sizes and size distributions were mixed with similar size brown glass into "glastic" composites having glass compositions of 15, 30, and 45 wt%. These prototypes were molded in a form similar to standard clay bricks at 235 • C and were compression tested to more than double the fracture stress of clay bricks at temperatures ranging from 20 to 50 • C. These prototypes illustrate the prospects for utilizing waste plastics and glass in simple commercial materials applications and the relief of land fill problems which are now world-wide.