| Army Corrosion Program Update |
09 Feb 2010 |
22 pages |
| Authors:
Mitchell H Stevenson; DEPARTMENT OF THE ARMY WASHINGTON DC
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 | AGENDA: Department of the Army G-4 Vision and Mission * Roles and Responsibilities of DA G-4 Related to Corrosion * Army Corrosion Structure * Army Corrosion Partners * Army Initiatives to Combat Corrosion * Challenges * Way Ahead * DEPARTMENT OF THE ARMY G-4 -- VISION: Enable a ready Army by providing and overseeing integrated logistics policies, programs, and plans in support of Army Force Generation. MISSION: Recognized as the ... |
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| RDECOM Corrosion Prevention and Control (CPC) Research, Development, Test and Evaluation Strategy |
09 Feb 2010 |
15 pages |
| Authors:
Erik Hangeland; ARMY RESEARCH DEVELOPMENT AND ENGINEERING COMMAND ABERDEEN PROVING GROUND MD ENVIRONMENTAL ACQUISITION AND LOGISTICS SUSTAINMENT PROGRAM
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| Corrosion Control Anniston Army Depot |
09 Feb 2010 |
11 pages |
| Authors:
Chris Coss; ANNISTON ARMY DEPOT AL
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| COATINGS: Oil/lube select parts * Anodize, Chrome, and Black Oxide * Substrate Prep and CARC paint. STOWAGE: Climate controlled storage (limited) * Weather resistant (rain, uv) stowage * Right Material -- Right Time. IN PROCESS ACTIONS: Installation of new cleaning technologies for small arms overhaul and plating operations that incorporate rust inhibition into final state. * 'Single Piece' flow through Bldg 409 * Advent of Automated Proportioners (eliminate hand mixing ... |
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| Moving Technical Knowledge into Decision Making |
09 Feb 2010 |
42 pages |
| Authors:
Cliff Johnson; NATIONAL ASSOCIATION OF CORROSION ENGINEERS HOUSTON TX
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| Development of High Strength Thermally Stable Al-based Alloys with Nanocomposite Structure |
05 Feb 2010 |
26 pages |
| Authors:
Valeriy V Maslov; INSTITUTE FOR METAL PHYSICS KIEV (UKRAINE)
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| This report results from a contract tasking Institute for Metal Physics, NAS of Ukraine as follows: The demands on materials set by aerospace and aircraft manufacturers include the development of alloys possessing high strength-to-weight ratios and capable to withstand high temperature exposures during service. One of the promising classes of materials which may meet these requirements are Al-based alloys with nanocomposite structures formed by partial crystallization of amorphous precursors the ... |
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| Ab Initio Calculations and Synthesis of Sc2InC-Y2InC Solid Solution |
03 Feb 2010 |
9 pages |
| Authors:
Jochen M Schneider; RWTH AACHEN UNIV (GERMANY)
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| This report results from a contract tasking RWTH Aachen as follows: The aim of this project is to contribute towards the development of novel tribological materials. It will study a solid solution of this fascinating new class of nanolaminated materials using both theoretical and experimental means. The M2InC system was selected based on our recent EOARD project (FA8655-05-1-3009). Our specific research directions are 1) to tailor shearing in Sc2InC-Y2InC solid ... |
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| Linewidth Narrowing and Purcell Enhancement in Photonic Crystal Cavities on an Er-Doped Silicon Nitride Platform |
01 Feb 2010 |
13 pages |
| Authors:
Yiyang Gong; Maria Makarova; Selcuk Yerci; Rui Li; Martin J Stevens; Burm Baek; Sae W Nam; Robert H Hadfield; Sander N Dorenbos; Val Zwiller; Jelena Vuckovic; Luca D Negro; STANFORD UNIV CA DEPT OF ELECTRICAL ENGINEERING
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| Light emission at 1.54 mm from an Er-doped amorphous silicon nitride layer coupled to photonic crystal resonators at cryogenic and room temperatures and under varying optical pump powers has been studied. The results demonstrate that small mode volume, high quality factor resonators enhance Er absorption and emission rates at the cavity resonance. Time resolved measurements give 11- to 17-fold Purcell enhancement of spontaneous emission at cryogenic temperatures, and 2.4-fold enhancement ... |
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| Small Fatigue Crack Growth and Failure Mode Transitions in a Ni-Base Superalloy at Elevated Temperature (Preprint) |
Feb 2010 |
30 pages |
| Authors:
M J Catona; S K Jha; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
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| A study of the long and small fatigue crack growth behavior in IN100 tested at 650 deg C both with and without dwell periods is summarized. A significant small crack effect is evident in this alloy, and it is observed that the influence of loading variables on small crack behavior is profoundly different from that on long cracks. While a 6-second dwell has negligible effect on long crack growth rates, ... |
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| Atomic-Scale Study of Plastic-Yield Criterion in Nanocrystalline Cu at High Strain Rates |
Feb 2010 |
11 pages |
| Authors:
A M Dongare; A M Rajendran; B Lamattina; D W Brenner; M A Zikry; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
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| Large-scale molecular dynamics (MD) simulations are used to understand the macroscopic yield behavior of nanocrystalline Cu with an average grain size of 6 nm at high strain rates. The MD simulations at strain rates varying from 10(exp 9)/sec to 8 x 9 10(exp)9/sec suggest an asymmetry in the flow stress values in tension and compression, with the nanocrystalline metal being stronger in compression than in tension. The tension-compression strength asymmetry ... |
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| Impact of Corrosion on Ground Vehicles: Program Review, Issues and Solutions |
Feb 2010 |
16 pages |
| Authors:
Ali Baziari; ARMY TANK-AUTOMOTIVE COMMAND WARREN MI
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| Influence future design and acquisition * Design with corrosion in mind * Adoption of new technology * Programmatic reviews * Improve current production, repair, upgrades * Identify product and process improvements * Materials and coatings improvements Protect fielded fleet * Coatings and inhibitors * Controlled environments * Vehicle assessments. Bottom Line: - Keep readiness rates up - Keep costs down. |
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| The Use of Zinc-Lead Composites to Prevent the Corrosion of Lead |
Feb 2010 |
16 pages |
| Authors:
Sean W Morefield; Weiss; Charles A Jr; Phillip G Malone; ENGINEER RESEARCH AND DEVELOPMENT CENTER CHAMPAIGN IL CONSTRUCTION ENGINEERING RESEARCH LAB
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| U.S. Marine Corps Corrosion Prevention and Control (CPAC) Program Overview |
Feb 2010 |
38 pages |
| Authors:
MARINE CORPS SYSTEMS COMMAND QUANTICO VA
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| OSD sponsored study found Cost of Corrosion to DoD is $22.4B a year * Annual Cost to Marine Corps Ground Equipment is $700M/yr (2005) * Effects Service Life, Readiness and Total Ownership Costs. Marine Corps Order 4790.18_ MISSION: To establish an effective CPAC program to extend the useful life of all Marine Corps tactical ground and ground support equipment. OBJECTIVE: Mitigate the Impact of Corrosion on USMC Assets through a ... |
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| The Use of Organic Humectants as Non-Corrosive Dust Control Agents |
Feb 2010 |
12 pages |
| Authors:
Sean W Morefield; Weiss; Charles A Jr; Philip G Malone; ENGINEER RESEARCH AND DEVELOPMENT CENTER CHAMPAIGN IL CONSTRUCTION ENGINEERING RESEARCH LAB
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| The Effect of Chlorides on the Correlation of Accelerated Laboratory Corrosion Tests to Out-Door Exposure Tests for Ceramics-Aluminum Couples |
Feb 2010 |
33 pages |
| Authors:
Raghu Srinivasan; L H Hihara; HAWAII UNIV HONOLULU (MANOA CAMPUS) DEPT OF MECHANICAL ENGINEERING
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| Data Analysis Supporting Army Aviation Corrosion Control and Prevention Investment Decisions |
Feb 2010 |
25 pages |
| Authors:
ARMY AVIATION AND MISSILE LIFE CYCLE MANAGEMENT COMMAND REDSTONE ARSENAL AL
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| PEO Missiles and Space Overview Briefing for the 2010 Corosion Summit |
Feb 2010 |
20 pages |
| Authors:
ARMY PROGRAM EXECUTIVE OFFICE (MISSILES AND SPACE) REDSTONE ARSENAL AL
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| Product Performance Verification for Highly Corrosive Environments |
Feb 2010 |
16 pages |
| Authors:
Pauline Smith; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
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| These briefing charts discuss the topic of corrosion, including costs of corrosion, product performance versus product safety compliance, importance of independent product performance verification, and understanding coatings. |
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| Missile Corrosion Prevention and Control |
Feb 2010 |
27 pages |
| Authors:
Donald Smallwood; Steven F Carr; ARMY AVIATION AND MISSILE LIFE CYCLE MANAGEMENT COMMAND REDSTONE ARSENAL AL
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| INTRODUCTION TO CORROSION: Why Are You Here? United States General Accounting Office (GAO) estimated the cost of corrosion to the DoD to be between $9 and $20 Billion annually * The Annual Cost of Corrosion for Army Aviation and Missile Equipment: Report SKT50T3 June 2007 * $1.6 Billion estimated annual corrosion maintenance cost to the Army Aviation and Missile Life Cycle Management Command (AMCOM) * The Annual Cost of Corrosion ... |
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| Corrosion Prevention and Control in the Army Warfighting Capability Development Process |
Feb 2010 |
10 pages |
| Authors:
James E Chambers; ARMY COMBINED ARMS SUPPORT COMMAND FORT LEE VA
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| Testing for Stray Current Corrosion in Earth Covered Magazines with EOP |
Feb 2010 |
27 pages |
| Authors:
O S Marshall; ENGINEER RESEARCH AND DEVELOPMENT CENTER CHAMPAIGN IL
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| OUTLINE: EOP Technology * Stray Current * Stray Current Testing * Test Findings * Recommended Test Procedures * Conclusion. BACKGROUND: Underground Structures inherently have moisture intrusion problems. Walls, floors, and ceilings * Rising damp * Wicking * High External Head * Joints and cracks. BACKGROUND: The water intrusion causes corrosion * Structural steel * Stored assets making many unusable * Mold and poor air quality. |
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| Aviation and Missile Corrosion Prevention and Control |
Feb 2010 |
30 pages |
| Authors:
Robert A Herron; ARMY AVIATION AND MISSILE LIFE CYCLE MANAGEMENT COMMAND REDSTONE ARSENAL AL
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| Use of Dilute Flowable Backfill for Corrosion Mitigation of Buried Pipe |
Feb 2010 |
17 pages |
| Authors:
Scott M Lux; Charlie Marsh; Tom Carlson; ENGINEER RESEARCH AND DEVELOPMENT CENTER CHAMPAIGN IL CONSTRUCTION ENGINEERING RESEARCH LAB
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| Army Corrosion Prevention and Control (CPC) Program for Facilities and Infrastructure |
Feb 2010 |
14 pages |
| Authors:
Craig E College; ASSISTANT CHIEF OF STAFF FOR INSTALLATION MANAGEMENT (ARMY) WASHINGTON DC
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| Partnership Research with the ERDC, MS&T and PPEC |
Feb 2010 |
19 pages |
| Authors:
Mike Koenigstein; PRO PERMA ENGINEERED COATINGS ROLLA MO
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| Design Considerations for Abrasive Blast Rooms and Recovery Systems |
Feb 2010 |
83 pages |
| Authors:
Bob Kerr; CLEMCO INDUSTRIES CORP SAN FRANCISCO CA
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| PLANNING CONSIDERATIONS: Enclosure * Location of Room * Completely Inside * Room Inside, Collector Outside * Completely Outside * Partially Outside * Recovery System Location * On Top of Existing Floor * Flush-Mounted (Recovery System In Pit) ... CLEMCO WORLDWIDE ... The demand for abrasive blasting is extensive. Ship building and maintenance in Singapore, construction in Saudi Arabia, refining in Houston... these are but a few of the major industries ... |
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| Protecting Stored Critical Parts from Corrosion and Heat Damage |
Feb 2010 |
17 pages |
| Authors:
Chip Crotty; COCOON INC NORTH HAMPTON NH
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| The GAO has identified corrosion as the single largest controllable cost in the weapons system life cycle with more than $20B spent annually to fight the effects of. * In 2003, the GAO report on Corrosion in the DoD (GAO-03-753) estimated that the Army's 2,770 helicopters and fixed-wing aircraft require $4B in corrosion repair annually (this translates to $1.4MM per aircraft per year in corrosion-related repair costs) Provide shelters and ... |
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| Impact of Corrosion on Ground Vehicles, Field Site Operations |
Feb 2010 |
30 pages |
| Authors:
Greg Bock; VSE CORP STERLING HEIGHTS MI
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| Prime contractor for U.S. Army and U.S. Marine Corps programs for over five years: Management support of the programs, to include vendors * Life cycle support: corrosion prevention techniques, processes, compounds, and controls. TARGET: Tactical Wheeled Vehicles and Ground Support Equipment. |
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| The Effective Behavior of Heterogeneous Ferromagnetic Materials |
31 Jan 2010 |
3 pages |
| Authors:
WASHINGTON UNIV SEATTLE
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| In the project, we have studied a variety of heterogeneous ferromagnetic materials, including ferromagnetic shape memory alloys, multiferroic materials, and ferromagnetic composites. The main achievements have been summarized as following: 1. A constrained theory of magnetoelastic materials has been developed to study the effective behavior of single-crystalline and polycrystalline ferromagnetic shape memory alloys (FSMA) based on nonlinear homogenization theory and variational principle. The actuation strain induced by domain switching under ... |
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| Aluminum Based Nanoeutectics: Synthesis and Microstructure |
30 Jan 2010 |
5 pages |
| Authors:
Kamanio Chattopadhyay; INDIAN INST OF SCIENCE BANGALORE (INDIA)
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| The primary aim of the project was to explore the possibility of synthesizing high strength multiphase eutectic alloys based on aluminium which also exhibits reasonable ductility. The approach used was to develop a multiscale microstructure including nanometer length scale eutectic colony using ternary alloys and evaluate their deformation behavior. We have carried out work on two alloy systems, Al-Cu-Si and Al-Fe-Ni. Both exhibit ternary eutectic reaction. The microstructures were manipulated ... |
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| Enhancement of Grain Refined Microstructure in a Nanostructured Metals via Ultrahigh Pressure Hydrostatic Consolidation Process - Construction of Master Sintering Curve (MSC) and Its Application to Densification of Al-Mg Alloy |
30 Jan 2010 |
9 pages |
| Authors:
Sangmok Lee; ASIAN OFFICE OF AEROSPACE RESEARCH AND DEVELOPMENT APO AP 96337-0007
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| Previously Al-Mg alloy was densified by hot isostatic processing and subsequently consolidated by hydrostatic extrusion. Through this process high strength and high formability nanostructured bulk Al-Mg alloy was fabricated. However, it is important to handle parametric control in powder metallurgical processing in terms of relative density, which is closely associated with its mechanical properties in acquiring a material of a desired property. At current stage processing parameter of density function ... |
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| Influence of Experimental Conditions on the Outcome of Laboratory Investigations Using Natural Coastal Seawaters |
Jan 2010 |
9 pages |
| Authors:
Jason S Lee; Richard I Ray; Brenda J Little; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
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| Methods for handling and storing natural coastal seawater, particularly methods for deaeration over time, influenced the chemistry and microflora. Bubbling nitrogen into natural seawater to achieve an anaerobic condition was not conducive to the growth of sulfate-reducing bacteria (SRB). Despite a higher initial dissolved sulfate concentration and higher total organic carbon in Persian Gulf seawater, higher dissolved sulfide concentrations and SRB populations were measured in Key West, Florida, seawater under ... |
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| On the Nucleation and Growth of Alpha-Ti Off of TiB Precipitates (PREPRINT) |
Jan 2010 |
27 pages |
| Authors:
T T Sasaki; B Fu; K Torres; G B Thompson; R Srinivasan; J S Tiley; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
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| We have investigated the microstructure of the beta-stabilized Ti-15Mo-2.6Nb-3Al-0.2Si-0.12B alloy at two different aging temperatures, 540 degrees C/8 hr and 660 degrees C/8 hr. At the lower aging temperature, alpha-Ti precipitated as needle-like shapes off of the TiB phase. In contrast, the higher aged sample exhibited globular alpha-Ti morphology around the TiB phase. This difference has been rationalized by the coarsening behavior of alpha-Ti around the TiB phase. Various orientation ... |
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| Probabilistic Fretting Fatigue Life Prediction of Ti-6Al-4V (PREPRINT) |
Jan 2010 |
35 pages |
| Authors:
Patrick J Golden; Harry R Millwater; Xiaobin Yang; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
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| A probabilistic analysis of the fatigue life of specimens subject to fretting fatigue was developed. A mechanics based fretting life analysis was applied that employed the local stress gradient at the edge of contact. The random variables in the analysis included the initial crack size, coefficient of friction, crack growth rate law, and the contact pad profile. The variation in pad profiles was determined through measurement of seventy-seven machined pads. ... |
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| Microstructural Evolution in Laser Deposited Nickel-Titanium-Carbon in Situ Metal-Matrix Composites (Preprint) |
Jan 2010 |
16 pages |
| Authors:
J Tiley; S Gopagoni; A R Singh; J Y Hwang; T W Scharf; R Banerjee; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
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| Laser deposition of a mixture of elemental nickel, titanium, and carbon (graphite) powders with varying compositions, via the laser engineered net shaping (LENS) process, has resulted in novel in situ metal-matrix composites. The microstructure in these in situ composites can be substantially tailored depending on the ratio of graphitic carbon to titanium added. A lower C/Ti ratio results in a harder composite consisting of primary titanium carbide precipitates within a ... |
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| Measurement of gamma prime Precipitates in a Nickel-Based Superalloy using Energy-Filtered Transmission Electron Microscopy Coupled With Automated Segmenting Techniques (Preprint) |
Jan 2010 |
16 pages |
| Authors:
J S Tiley; G B Viswanathan; A Shiveley; M Tschopp; R Srinivasan; H L Fraser; R Banerjee; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH METALS BRANCH
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| Precipitates of the ordered L1(sub 2) gamma prime phase (dispersed in the face-centered cubic or FCC gamma matrix) were imaged in Rene 88 DT, a commercial multicomponent Ni-based superalloy, using energy filtered transmission electron microscopy (EFTEM). Imaging was performed using the Cr, Co, Ni, Ti and Al elemental L-edges in the energy loss spectrum. Manual and automated segmentation procedures were utilized for identification of precipitate boundaries, measurement of precipitate sizes ... |
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| Investigation of Variability in Fatigue Crack Nucleation and Propagation in Alpha+Beta Ti-6Al-4V |
Jan 2010 |
10 pages |
| Authors:
Patrick J Golden; Reji John; Porter; W J III; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
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| The understanding of fatigue variability in turbine engine materials is vital to permit a reduction of US Air Force sustainment costs through fatigue life extension and/or inspection interval extension. Additionally, the US Air Force is currently moving further towards the use of probabilistic damage tolerance design methods. These probabilistic models require not only a good understanding of the variability in specimen data, but also an understanding of the microstructural sources ... |
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| Digital Representation of Materials Grain Structure |
Jan 2010 |
53 pages |
| Authors:
Michael A Groeber; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
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| Recent initiatives to accelerate the insertion of materials and link the materials design and systems design processes have called for the advancement of microstructure-property relationships. In order to achieve these goals, the development of digital microstructure models in conjunction with computational methods for simulating material response is a necessity. There have been significant advancements in the collection and representation of microstructure, which coupled with computational power increases, has yielded microstructure ... |
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| Classification of Corrosion Defects in NiAl Bronze Through Image Analysis |
Jan 2010 |
7 pages |
| Authors:
Ramana M Pidaparti; Babak S Aghazadeh; Angela Whitfield; A S Rao; Gerald P Mercier; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD
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| Corrosion surface damage in the form of pitting and micro-cracks is observed in many metals. Cracks usually initiate from the pits and grow under cyclic stresses and eventually lead to material failure. An image analysis based on wavelet transforms and fractals was used to study the corrosion morphology of nickel aluminum bronze metal under varying corrosion conditions and applied stresses. Image feature parameters were extracted and analyzed to classify the ... |
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| Maskless Shaping of Gold Stud Bumps as High Aspect Ratio Microstructures |
Jan 2010 |
6 pages |
| Authors:
Rekha S Pai; Mark M Crain; Kevin M Walsh; LOUISVILLE UNIV KY DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
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| Micro/nanoimprinting is a simple and economical way of patterning polymeric structures over large areas. This paper seeks to extend this technique to fabricate three dimensional (3D) metallic microstructures even in trenches and constrained areas using a flip chip bonder in conjunction with a wire bonder. In this two step process, gold stud bumps were placed first on sputtered metal at appropriate locations using a wire bonder capillary tool. The second ... |
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| Self-Aligned ALD AlOx T-gate Insulator for Gate Leakage Current Suppression in SiNx-Passivated AlGaN/GaN HEMTs |
Jan 2010 |
8 pages |
| Authors:
David J Meyer; Robert Bass; D S Katzer; David A Deen; Steven C Binari; Kevin M Daniels; Eddy; Charles R Jr; NAVAL RESEARCH LAB WASHINGTON DC ELECTRONICS SCIENCE AND TECHNOLOGY DIV
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| A proof-of-concept metal-insulator-semiconductor (MIS) AlGaN/GaN high-electron mobility transistor (HEMT) that uses a self-aligned 10 nm AlOx gate insulator and SiNx passivation in the device access regions was investigated. Self-alignment of the gate insulator to metal was achieved by utilizing a submicron tri-layer photoresist pattern to lift-off sequentially-deposited AlOx dielectric and Ni/Au gate metal layers. By keeping the temperature low (100 C) during the atomic-layer deposition (ALD) of AlOx, reflow of ... |
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| Consequences of Anode Interfacial Layer Deletion. HCl-Treated ITO in P3HT:PCBM-Based Bulk-Heterojunction Organic Photovoltaic Devices |
Jan 2010 |
12 pages |
| Authors:
Michael D Irwin; Jun Liu; Benjamin J Leever; Jonathan D Servaites; Mark C Hersam; Michael F Durstock; Tobin J Marks; NORTHWESTERN UNIV EVANSTON IL MATERIALS RESEARCH CENTER
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| In studies to simplify the fabrication of bulk-heterojunction organic photovoltaic (OPV) devices, it was found that when glass/tin-doped indium oxide (ITO) substrates are treated with dilute aqueous HCl solutions, followed by UV-ozone (UVO), and then used to fabricate devices of the structure glass/ITO/P3HT:PCBM/LiF/Al, device performance is greatly enhanced. Light-to-power conversion efficiency (Eff) increases from 2.4% for control devices in which the ITO surface is treated only with UVO, to 3.8% ... |
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| Scaling Projections for Sb-based p-channel FETs |
Jan 2010 |
11 pages |
| Authors:
M G Ancona; B R Bennett; J B Boos; NAVAL RESEARCH LAB WASHINGTON DC ELECTRONICS SCIENCE AND TECHNOLOGY DIV
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| Numerical device modeling is used to study p-channel FETs with InSb, GaSb and InGaSb channels. To be as realistic as possible, the basic parameters are chosen to be those measured experimentally in state-of-the- art high-mobility materials, and where possible, predictions are compared against published data. Confinement effects are captured in the simulations using the density-gradient description of quantum transport. The emphasis is on projecting scaling properties and ultimate performance, with ... |
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| Non-equilibrium GaNAs Alloys with Band Gap Ranging from 0.8-3.4 eV |
Jan 2010 |
4 pages |
| Authors:
K M Yu; S V Novikov; R Broesler; C R Staddon; M Hawkridge; Z Liliental-Weber; I Demchenko; J D Denlinger; V M Kao; F Luckert; CALIFORNIA UNIV BERKELEY LAWRENCE BERKELEY LAB
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| A new alloy system, the GaN(sub 1-x)As(sub x) alloys in the whole composition range was successfully synthesized using the non-equilibrium low temperature molecular beam epitaxy method. The alloys are amorphous in the composition range of 0.17 x 0.75 and crystalline outside this region. The amorphous films have smooth morphology, homogeneous composition and sharp, well defined optical absorption edges. The bandgap energy varies in a broad energy range from ... |
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| Activated States for Cross-slip at Screw Dislocation Intersections in Face-Centered Cubic Nickel and Copper via Atomistic Simulation |
Jan 2010 |
12 pages |
| Authors:
S I Rao; D M Dimiduk; J A El-Awady; T A Parthasarathy; M D Uchic; C Woodward; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIR METALS CERAMICS AND NONDESTRUCTIVE EVALUATION DIV/METALS BRANCH
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| We extend our recent simulation studies where a screw dislocation in face-centered cubic (fcc) Ni was found to spontaneously attain a low energy partially cross-slipped configuration upon intersecting a forest dislocation. Using atomistic (molecular statics) simulations with embedded atom potentials, we evaluated the activation barrier for a dislocation to transform from fully residing on the glide plane to fully residing on a cross-slip plane intersecting a forest dislocation in both ... |
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| On the Role of Built-in Electric Fields on the Ignition of Oxide Coated NanoAluminum: Ion Mobility versus Fickian Diffusion |
2010 |
13 pages |
| Authors:
Brian J. Henz; Takumi Hawa; MICHAEL R. ZACHARIAH; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
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| Using the classical molecular dynamics method we simulate the mechanochemical behavior of small, core diameter <10 nm oxide coated aluminum nanoparticles. Aluminum nanoparticles with core diameters of approximately 5 and 8 nm are simulated with 1 and 2 nm thick oxide coatings or shells. In addition to thickness the shells are parametrized by varying degrees of crystallinity, density, and atomic ratios in order to study their effect on the ignition ... |
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| Nitrogen Rings and Cages Stabilized by Metallic Atoms |
18 Dec 2009 |
6 pages |
| Authors:
Gabriel Merino; Manuel Villanueva; Francisco Tenorio; Oscar Jimenez-Halla; America Bravo; Kristel Garcia; Cristina Santiago; UNIVERSIDAD DE GUANAJUATO DEPARTAMENTO DE QUIMICA
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| Over the last four years, our research has been focused on the prediction of new molecular species. The initial aim of this project was to study on paper new nitrogen compounds that were stabilized by metal centers. We did not find any new attractive nitrogen species. However, the algorithms developed during this project are universal and allow us to study other interesting chemical systems like silicon-lithium clusters. Particularly, we developed ... |
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| Dynamic Loading Characteristics in Metals and Composites |
Dec 2009 |
54 pages |
| Authors:
Kian Sing Tan; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| This study investigates the mechanical characteristics of aluminum alloy AA3003-H14 when it is subjected to dynamic axial loads at low strain rates of less than 1/s. The tensile experiments show that both the ultimate and yield stresses, as well as the absorbed strain energy, increase with strain rate. Moreover, the strains at yield, ultimate load and fracture show positive sensitivity to strain rate. On the other hand, when the material ... |
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| Evaluation of the Effects of Hydrogen Peroxide on Common Aviation Structural Materials |
Dec 2009 |
21 pages |
| Authors:
S F Chou; M H Sk; N I Sofyan; R A Overfelt; W F Gale; H S Gale; C G Shannon; J W Fergus; J Watson; AUBURN UNIV AL NATIONAL AIR TRANSPORTATION CENTER OF EXCELLENCE FOR RESEARCH IN THE INTERMODAL TRANSPORT ENVIRONMENT
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| Infected passengers can unintentionally contaminate the interior of aircraft; deliberate biological contamination from criminals and international adversaries is also possible. Previous work has provided information regarding the delivery mechanism and capability of STERIS Corporation's Vaporized Hydrogen Peroxide (VHP*) technology as a decontaminant/disinfectant/sanitizer for transportation vehicles like aircraft, buses, subway trains, ambulances, etc. The present report documents a materials compatibility evaluation of the effects of hydrogen peroxide exposure on the physical ... |
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| Prediction of Formation of Amorphous Alloys During Annealing of Ti-binary Alloys and Validation of the Same |
22 Nov 2009 |
78 pages |
| Authors:
S Ranganathan; NATIONAL METALLURGICAL LAB JAMSHEDPUR (INDIA)
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| Observation of an amorphous phase produced on annealing has excited scientists since the process can be easily controlled leading to bulk amorphous alloys that can find several technological applications. However, this phenomenon has to be explored further and understood in order to exploit it. It is important to understand the thermodynamics of this unusual phase transformation. This can lead to a better understanding of the fundamental aspects of this process. ... |
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| Templated Synthesis of Aluminum Nanoparticles - A New Route to Stable Energetic Materials |
05-Nov-2009 |
5 pages |
| Authors:
Heting Li; Mohammed J Meziani; Fushen Lu; Christopher E Bunker; Elena A Guliants; Ya-Ping Sun; CLEMSON UNIV SC
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| Nanoscale structural cavities in ionomer membrane films were used as templates for the facile synthesis of small aluminum nanoparticles via catalytic decomposition of an alane precursor. The loading of reactive aluminum in the composite film could be varied, up to more than half of the film weight. While the embedded nanoparticles were protected by the membrane structure from any significant oxidation for the composite films to exhibit surprising stability in ... |
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Properties of Metals and Alloys
