| USN Fleet Corrosion Control: Future Navy Needs for Corrosion Control and Maintenance |
13-Jan-2009 |
20 pages |
| Authors:
Rich Hays; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD
|
 | FUTURE FOCUS: Affordability * Fleet Readiness * Effective Execution of Programs * Efficient Use of Tools (Design, Inspection, Monitoring) * TECHNICAL KNOWLEDGE, CAPABILITY AND TOOLS: Use of Non-traditional Alloys * Aluminum Structure * High Strength * New Applications * Reduced conservatism and Redundancy * Mixed metals * Extended Service Life * Added Environmental Stressors * Reliance on Risk Analysis * Knowledge * Tool Sets. |
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| Development of a Novel Approach for Fatigue Life Prediction of Structural Materials |
Dec-2008 |
155 pages |
| Authors:
Yanyao Jiang; NEVADA UNIV RENO DEPT OF MECHANICAL ENGINEERING
|
| Experiments were conducted to study the fatigue initiation and crack growth of four structural materials: aluminum 7075T651 alloy, stainless steel AL6-XN, stainless steel 304L, and Aerospace Steel 4340. It was confirmed that fatigue can occur under compression-compression loading for the aluminum alloy. Results from multiaxial fatigue experiments revealed that the fatigue cracking behavior was material and loading amplitude dependent. Under cyclic pure shear loading, the S-N curves of aluminum alloy ... |
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| Development of a Ballistic Specification for Magnesium Alloy AZ31B |
Dec-2008 |
52 pages |
| Authors:
Tyrone L Jones; Richard D DeLorme; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| The U.S. Army Research Laboratory (ARL) and Magnesium Elektron North America (MENA) have conducted a joint effort to develop and evaluate rolled plate in commercially available magnesium alloy-temper AZ31B-H24. MENA produced the rolled product and conducted the mechanical analysis, while ARL performed the ballistic analysis. The magnesium alloy plates were parametrically compared with the minimum performance requirements of aluminum alloy 5083-H131 temper rolled plate using various armor-piercing and fragment-simulating projectiles ... |
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| Variability in Component Life Due to Fatigue Crack Growth Variability (Preprint) |
Oct-2008 |
26 pages |
| Authors:
A H Rosenberger; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| The variation in component damage tolerance life is assessed in terms of the variation in crack growth rate using a cycle by cycle integration technique. The results of a fatigue crack growth rate interlaboratory study are reanalyzed in order to predict the life of a component-like structure. It was determined that the variability in crack growth rate is fundamentally the same as the variability in the predicted fracture mechanics life ... |
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| Imaging Tools and Thin Film Coatings for Corrosion Prevention in Aluminum Alloys |
18 JAN 2008 |
4 pages |
| Authors:
Daniel A. Buttry; WYOMING UNIV LARAMIE DEPT OF CHEMISTRY
|
| The fundamental activities involved use of various imaging techniques to study corrosion processes that occur at metal surfaces. We applied these methods to understand both the anodic and cathodic processes involved in corrosion at Al alloy surfaces, and how those processes are influenced by environmental conditions. The applied activities were development and testing of new corrosion inhibition systems based on blends of thermoplastics and conducting polymers. These blends contain smart ... |
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| Effects of Strain Path on the Microstructure of Aluminum Alloys During Equal Channel Angular Pressing (ECAP) |
DEC 2007 |
71 pages |
| Authors:
Katrina M. Houston; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Aluminum alloys AA1050 and AA6061 were processed by ECAP following either monotonic or redundant routes. The materials were characterized by optical microscopy and orientation imaging microscopy. Grain shape changes were analyzed in different billet planes to assess microstructure refinement mechanisms and were consistent with a proposed model. The results demonstrate that microstructure development is not independent of processing route. In the case of AA6061, annealing characteristics were examined to determine ... |
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| The "Lazy S" Feature in Friction Stir Welding of AA2099 Aluminum -Lithium Alloy |
DEC 2007 |
63 pages |
| Authors:
Holli K. Klages; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The addition of Lithium to Aluminum-Lithium (Al-Li) alloys results in reduced density as well as increased stiffness and strength, and so these materials are attractive for selected aerospace structures. Friction Stir Welding (FSW) of Al-Li alloys may provide high join efficiency in such structures but potential FSW defects must be understood. This thesis examines the occurrence of the "Lazy S: feature, which may be a defect. Welds were made after ... |
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| Magnesium Rich Primer for Chrome Free Protection of Aluminum Alloys (Preprint) |
DEC 2007 |
19 pages |
| Authors:
Joel A. Johnson; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH NONSTRUCTURAL MATERIALS BRANCH
|
| Hexavalent chromium compounds used for corrosion protection are one of the top hazardous waste materials generated by the U.S. Air Force and legislation is in effect to further restrict their use. Magnesium rich primers that utilize sacrificial magnesium metal pigment to cathodically protect aerospace aluminum alloy substrates are a potential alternative to chromated primers. This material has proven to be particularly effective as part of a completely chromate-free coating system ... |
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| Assessment of the Effect of Pitting Corrosion on the Safe Life Prediction of the P-3C |
DEC 2007 |
|
| Authors:
Alexandra Shekhter; Christopher Loader; Weiping Hu; Bruce R. Crawford; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION VICTORIA (AUSTRALIA) AIR VEHICLES DIV
|
 | This report presents the results of an experimental programme aimed at assessing the implications of pitting corrosion damage on P-3C safe lives calculated using the methods developed in the P-3C Service Life Assessment Program, the Equivalent Crack Size method and the Crack Initiation method. The results of both of these methods were that, for the pitting corrosion distribution used, the safe life prediction was not invalidated by corrosion. However, larger ... |
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| Fiber Optic Strain Sensors (FOSS) to Monitor Strains on a Navy Vessel During Operations |
23 NOV 2007 |
12 pages |
| Authors:
Jonathan M. Nichols; Mark Seaver; Stephen T. Trickey; Kenneth C. Scandell; Liming Salvino; NAVAL RESEARCH LAB WASHINGTON DC OPTICAL TECHNIQUES BRANCH
|
| This document summarizes the recent deployment of a fiber optic strain sensing (FOSS) system to monitor loads on a Navy Vessel, as requested and authorized by Commander Naval Surface Force, Atlantic. The objectives were to (1) conduct an in-service validation of the technology onboard a U.S. Navy ship and (2) determine contributing influences to recurring cracking of [new] deckplate, as described by the Southeast Regional Maintenance Center (SERMC) Port Engineer. ... |
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| Shot-Peening Sensitivity of Aluminum With Corrosion-Preventive Coatings |
NOV 2007 |
60 pages |
| Authors:
Scott Grendahl; Daniel Snoha; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| The U.S. Army Aviation and Missile Research, Development, and Engineering Center Aviation Engineering Division (Huntsville, AL) requested that the U.S. Army Research Laboratory Weapons and Materials Research Directorate (Aberdeen Proving Ground, MD) execute a program aimed at evaluating the shot-peening sensitivity of 7075-T73 aluminum with U.S. Army corrosion-preventive coatings for aluminum. The coatings represent the two most common coatings for aviation aluminum alloys. The study was a follow-up to previous ... |
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| Impact Response of Sandwich Plates with a Pyramidal Lattice Core |
20-Jul-2007 |
18 pages |
| Authors:
Haydn N Wadley; Christian J Yungwirth; John H O'Connor; Alan J Zakraysek; Vikram S Deshpande; VIRGINIA UNIV CHARLOTTESVILLE DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| The ballistic performance edge clamped 304 stainless-steel sandwich panels has been measured by impacting the plates at mid-span with a spherical steel projectile whose impact velocity ranged from 250 to 1300 ms(-1). The sandwich plates comprised two identical face sheets and a pyramidal truss core: the diameter of the impacting spherical projectile was approximately half the 25 mm truss core cell size. The ballistic behavior has been compared with monolithic ... |
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| Titanium Brazing for Structures and Survivability |
MAY 2007 |
12 pages |
| Authors:
Kevin J. Doherty; Jason R. Tice; Steven T. Szewczyk; Gary A. Glide; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| Titanium is a candidate as a structural material for all new tactical and armored ground vehicles, because of its high strength-to-weight ratio, excellent corrosion resistance, and inherent ballistic resistance. However, titanium as a structural material is much less mature than both steel and aluminum alloys, especially in the area of joining. While welding is the typical joining method for titanium, vacuum brazing is an option in areas that are difficult ... |
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| Technical Operations Support (TOPS) II. Delivery Order 0022: Research and Development of Advanced Aerospace Coatings |
01-Mar-2007 |
17 pages |
| Authors:
UNIVERSAL TECHNOLOGY CORP DAYTON OH
|
| The objective of this Delivery Order was to conduct basic research on development of novel materials for advanced aerospace coating applications. This research effort included development of quasi-crystal metallurgical and sol-gel coating materials for improved corrosion protections of aerospace aluminum alloys. Thorough testing and analysis of coatings structure and properties, investigation of mechanisms of their protection action, as well as understanding of structure-properties relationship for these materials was also included ... |
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| Fretting Wear-Resistant, Micro-Arc Oxidation Coatings for Aluminum and Titanium Alloy Bearings (Preprint) |
MAR 2007 |
23 pages |
| Authors:
K. J. Choppy; R. F. Kovar; B. M. Cushman; INFOSCITEX CORP WALTHAM MA
|
| This report was developed under a SBIR contract, and has been released to the public by Infoscitex. Aluminum and titanium alloys are used as replacements for steel in gear boxes of aircraft and helicopters in both military and commercial air vehicles, due to their low density, mechanical strength and thermal conductivity. However, these alloys are susceptible to fretting wear when matched to harder steel surfaces under high loads at elevated ... |
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| Novel, One-Step, Chromate-Free Coatings Containing Anticorrosion Pigments for Metals That Can Be Used in a Variety of Industries |
2007 |
9 pages |
| Authors:
A. Ashirgade; P. Puomi; W. J. van Ooij; S. Bafna; A. Seth; C. Shivane; CINCINNATI UNIV OH DEPT OF CHEMICAL AND MATERIALS ENGINEERING
|
| The concept of superprimers, i.e., primers for metals with the conversion coating built in, has proven to be feasible. Such primers can be applied on any bare metal, provided it is reasonably clean. These primers are based on water-dispersed organic resins and organofunctional silanes, which assure good adhesion both to the substrate and the overcoat. In this paper we will discuss an epoxy-novolac based system for AA20242-T3, but we will ... |
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| Friction Stir Processing Parameters and Property Distributions in Cast Nickel Aluminum Bronze |
DEC 2006 |
67 pages |
| Authors:
Brian P. Rosemark; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF MECHANICAL ENGINEERING
|
| Cast nickel-aluminum bronze (NAB) alloy is specified for many marine applications, including ship propellers, due to its excellent corrosion-resistance combined with acceptable mechanical properties. Friction stir processing (FSP) can be used to improve the alloy's mechanical properties by localized microstructure modification in the cast material. FSP converts an as-cast microstructure to a wrought condition in the absence of macroscopic shape change, closes porosity, and provides a means to surface harden ... |
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| Unlubricated Gross Slip Fretting Wear of Metallic Plasma Sprayed Coatings for Ti6A14V Surfaces |
NOV 2006 |
37 pages |
| Authors:
Jr. Hager Carl H.; Jeffrey H. Sanders; Shashi K. Sharma; UNIVERSAL TECHNOLOGY CORP DAYTON OH
|
| Plasma sprayed Al-bronze (Al-Br) or CuNiIn coatings are often applied to protect against fretting wear and extend the operational life of Ti-alloy compressor blades in turbine engines. In order to develop a fundamental understanding of how these coating systems perform under gross slip fretting conditions, bench level fretting wear tests were conducted at room temperature to simulate cold engine startup. Alternative coatings such as plasma sprayed molybdenum and nickel were ... |
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| The Development of an Environmentally Compliant, Multi-Functional Aerospace Coating Using Molecular- and Nano-Engineering Methods |
02 OCT 2006 |
135 pages |
| Authors:
S. R. Taylor; G. J. Shiflet; J. R. Scully; R. G. Buchheit; W. J. van Ooij; K. Sieradzki; R. E. Diaz; C. J. Brinker; A. L. Moran; MISSISSIPPI UNIV MEDICAL CENTER JACKSON
|
| The coating system presently used on military aircraft is constrained in function (e.g., static color, low glint) and limited to the use of toxic, chromate-based compounds for the mitigation of corrosion. This report summarizes a MURI that was tasked to establish the scientific foundation for a military aerospace coating with expanded functionality and environmental compliance. By implementing advances in molecular and nano-engineered materials, an academic team has identified the enabling ... |
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| Mechanism and Inhibition of Oxygen Reduction on Light Weight Alloys |
01 JUL 2006 |
11 pages |
| Authors:
Richard McCreery; Gerald Frankel; OHIO STATE UNIV COLUMBUS DEPT OF CHEMISTRY
|
| Inhibition of oxygen reduction is a very effective means for reducing corrosion of Al alloys and many other materials. The oxygen reduction reaction is quite complex, and very dependent on the existence of catalytic sites on the metallic surface. Recent projects on Al corrosion and inhibition have identified the importance of oxygen reduction, but have not elucidated the mechanism or the most effective means for its inhibition. The work proposed ... |
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| Residual Stress, Micro- and Macrotexture in Surface-Enhanced Titanium Alloys: Their Nondestructive Inspection and Effects on High-Cycle Fatigue Properties |
MAY 2006 |
49 pages |
| Authors:
Chi-Sing Man; Tongguang Zhai; KENTUCKY UNIV LEXINGTON
|
| An acousto-elastic method was developed to estimate the residual stress and texture of a flat metal surface by simultaneous measurement of Rayleigh waves and surface skimming longitudinal waves (or P waves). The method showed promise in the successful recovery of surface residual stress in an AA 7076-T651 aluminum sample surface-treated by low plasticity burnishing. The effects of sandblasting and shot peening on a commercially pure titanium, a Ti-6Al-4V titanium alloy, ... |
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| Study of Hydraulic System Component Storage with a Rust Inhibited Barium Free Development Hydraulic Fluid Candidate |
APR 2006 |
21 pages |
| Authors:
Lois J. Gschwender; Angie Campo; Carl E. Snyder; Shashi K. Sharma; Tim Jenney; George Fultz; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| METSS Corporation, under a Small Business Innovation Research program (F33615-96-C-5074) with AFRL/MLBT, developed a hydraulic fluid candidate known as METTS HyTherm CI-2. This fluid is intended to be rust inhibited, barium free, thermally stable and fire resistant hydraulic fluid suitable for aircraft use. METSS HyTherm CI-2 would eliminate the need for a separate storage fluid for components. The currently used storage fluid is classified as hazardous waste due to the ... |
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| A Preparation Technique for Microscopy Samples of Mechanically Alloyed Nickel-Coated Aluminum Powders |
APR 2006 |
15 pages |
| Authors:
George T. Dewing; Franklyn R. Kellogg; Bradley R. Klotz; Laszlo J. Kecskes; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| A method for the preparation of fine powders for microscopic examination of their cross section is described. Heavily worked nickel-coated aluminum powders were mounted in epoxy and polished to a mirror finish to allow for the characterization of their interior structure. The method presented would be applicable to all types of finely divided media. |
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| Novel Electroactive Polymers as Environmentally Compliant Coatings for Corrosion Control |
03-Feb-2006 |
189 pages |
| Authors:
Florian Mansfeld; Jun Xu; Peter Zarras; Wynne; J Kenneth; Dennis E Tallman; Brian C Benicewicz; Gay Kendall; NAVAL AIR WARFARE CENTER WEAPONS DIV CHINA LAKE CA
|
| The objectives of this SERDP program (WP 1148) have been completed successfully. The synthesis, scale-up and characterization of new monomers based on a bis-amino derivative of poly-p-phenylene vinylene (PPV) called poly(2,5-bis(N-methyl-N-hexylamino)phenylene vinylene, (BAM-PPV) and oligomers of polyaniline have been completed. These polymers have been thoroughly characterized using advanced spectroscopic and analytical methods. The details regarding the EAP synthesis has been published in the literature for duplication including potential industrial use. ... |
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| The Effect of Friction Stir Processing on the Microstructure and Mechanical Properties of AF/C458 Aluminum Lithium Alloy |
SEP 2005 |
87 pages |
| Authors:
Tanya L. Giles; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Aluminum-lithium alloys have been under development for lightweight-high strength aerospace structures but implementation has been slowed significantly because of poor short transverse fracture toughness and brittle intergranular delamination cracking. The alloy AF/C458 (now designated AA 2099) has been designed to exhibit decreased mechanical anisotropy and improved fracture toughness while maintaining ductility and strength levels. This thesis examines the application of Friction Stir Processing (FSP) of AF/C458 as an approach to ... |
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| Air Vehicle Technology Integration Program (AVTIP). Delivery Order 0033: Advanced Sol-Gel Adhesion Processes - Transition Support |
JUL 2005 |
80 pages |
| Authors:
Kay Y. Blohowiak; Jacob W. Grob; Jill E. Seebergh; BOEING CO SEATTLE WA
|
| This report summarizes optimization and transition support work for surface preparations utilizing nanostructured sol-gel coatings on metal alloy substrates. The project focuses on optimization and transition of user-friendly sol-gel methods for preparing metal surfaces for bonding with 250 deg F-cure epoxy adhesives. Studies indicate that careful choice of abrasive media and tools is required to achieve reproducible performance for the surface preparation of aluminum alloys. Verification of these processes and ... |
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| Synthesis of Bulk Nanostructured Al Alloys with Ultra-High Strength and Wear Resistance for Army Applications |
26 APR 2005 |
24 pages |
| Authors:
E. J. Lavernia; CALIFORNIA UNIV DAVIS
|
| Synthesis/processing of nanostructured (amorphous or ultra fine grained) materials was studied via various processing routes such as gas atomization, melt spinning, cryomilling, equal-channel angular pressing (ECAP) and conventional consolidation. Microstructures and mechanical properties of both the amorphous powders and consolidated bulk materials were characterized. The amorphous alloy of A185Ni10La5 (at.%) was fabricated in terms of melt-spun ribbons and particularly, gas-atomized powders (283 degs, the devitrification tends to complete in a ... |
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| Evaluation of Corrosion Preventive Compounds for Aviation Materials Applications |
APR 2005 |
149 pages |
| Authors:
Brian E. Placzankis; Chris E. Miller; Scott M. Grendahl; Tracey L. Miller; Stephanie M. Piraino; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Corrosion preventive compounds (CPCs) were evaluated using substrates comprised of five commonly used rotary wing aviation materials. The materials used were magnesium alloy AZ31B-H24 aluminum alloy 2024-T3, 4130 low alloy steel. 4340 high strength steel, and AM-355 stainless steel. The relative performance of each CPC was assessed in combination with the materials under several different tests. These tests consisted of general corrosion resistance. resistance to crevice corrosion attack. stress corrosion ... |
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| Structure Synthesis and Kinetics During Undercooled Liquid Solidification and Intense Plastic Deformation |
29 MAR 2005 |
19 pages |
| Authors:
John H. Perepezko; WISCONSIN UNIV-MADISON DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| At high undercooling, solidification is rapid and can result in the suppression of the usual reactions to yield amorphous phases and nonequilibrium crystalline phases with novel microstructures. In a complimentary approach, the intense deformation of an elemental layered array drives an atomic scale mixing at the interfaces to yield alloying and in some systems an amorphization reaction. Similarly, deformation of amorphous ribbons can drive instabilities that result in the development ... |
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| Microstructural Control of a Precipitate-Hardenable Al-Ag Alloy Using Severe Plastic Deformation |
23 MAR 2005 |
6 pages |
| Authors:
Kunihiro Ohashi; Takeshi Fujita; Keiichiro Oh-ishi; Kenji Kaneko; Zenji Horita; KYUSHU UNIV FUKUOKA (JAPAN) DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| An Al-10.8wt%Ag alloy was subjected to aging treatment followed by Equal-Channel Angular Pressing (ECAP) (designated process AE) or ECAP followed by aging treatment (designated process EA). Hardness measurements were undertaken with respect to the number of ECAP passes for process AE or with respect to aging time for process EA. Microstructures were examined by transmission electron microscopy (TEM) including X-ray mapping. It is shown that age hardening is observed for ... |
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| Processing and Properties of Mechanical Alloyed Al93Fe3Cr2Ti2 Alloys |
23 MAR 2005 |
6 pages |
| Authors:
L. Shaw; H. Luo; J. Villegas; D. Miracle; CONNECTICUT UNIV STORRS
|
| Nanostructured Al93Fe3Ti2Cr2 alloys were prepared via mechanical alloying (MA) starting from elemental powders, followed by extrusion to form bulk material. The microstructure and phase formation as a function of the milling time and the concentration of the process-control agent were investigated. The thermal stability of the mechanical alloyed powder was also studied. The bulk material extruded from the mechanical alloyed powder exhibited superior strength with good ductility at both ambient ... |
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| Electronic Structure and Mechanical Properties of Metals and Intermetallics |
10 DEC 2004 |
17 pages |
| Authors:
Nicholas Kioussis; CALIFORNIA STATE UNIV NORTHRIDGE CA DEPT OF PHYSICS
|
| State-of-the-art first-principles electronic structure calculations based on the full-potential linear-muffin-tin-orbital method and the pseudopotential method were employed to study systematically: 1) The dislocation core properties of the clean aluminum and silver systems; 2) The effect of sampling scheme of the misfit energy across the glide plane; 3) The Hydrogen- enhanced local plasticity in aluminum; 4) The correlation of the topology of the electronic charge density with the energetics and stability ... |
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| Issues of Compatibility Between Nanomaterials and Aluminum Scanning Electron Microscopic Mounts |
DEC 2004 |
18 pages |
| Authors:
Donovan Harris; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| Aluminum mounts are ubiquitously present in scanning electron microscope (SEM) laboratories. They are an inexpensive light material with good conductivity properties, and are generally compatible with conductive adhesive products. In the course of using aluminum mounts to examine nanoscale materials, some compatibility issues were revealed. One limiting issue was charge conduction. Nanoscale materials can be a more efficient conductor of electrons than the aluminum mount with its layer of oxides. ... |
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| Prediction of Ductile Fracture of Thin-Walled Cylinders Subjected to Localized Intense Heat |
30 NOV 2004 |
77 pages |
| Authors:
C. T. Sun; Z. Jin; S. Kalyanam; Nick Bruno; Adam Deitemeyer; PURDUE UNIV LAFAYETTE IN
|
| The objective of this research was to further develop two models that are capable of predicting crack growth in ductile materials. In this study, we measured CTOA (crack tip opening angle) at elevated temperatures for a stainless steel and aluminum alloy 2014-T6. The CTOA curves were then used as the fracture criterion to simulate crack extension and instability in thin-walled cylinders subjected to localized intense heat. The commercial finite element ... |
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| Corrosion Behavior of Friction Stir Welded High Strength Aluminum Alloys |
27 OCT 2004 |
12 pages |
| Authors:
J. B. Lumsden; M. W. Mahoney; G. A. Pollock; ROCKWELL SCIENTIFIC CO THOUSAND OAKS CA
|
| Friction stir welding (FSW), a relatively new solid state joining process, is used to join aluminum alloys of all compositions including alloys essentially considered unweldable. During FSW, a rotating tool provides a continual hot working action, plasticizing metal within a narrow zone at the join line, while transporting metal from the leading face of the probe to the trailing edge as the tool moves along the interface. Although melting does ... |
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| Effect of Sonic Thermographic Inspection on Fatigue Crack Growth in an Al Alloy |
OCT 2004 |
|
| Authors:
Kelly A. Tsoi; Nik Rajic; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION VICTORIA (AUSTRALIA) AIR VEHICLES DIV
|
| Sonic thermography has recently emerged as an important inspection technique capable of resolving inspection problems that contemporary methods have struggled with, such as tightly closed cracks in metallic structures and kissing bonds in composite repairs. The technique uses elastic waves injected by an acoustic horn resonating at typically either 20 or 40 kHz, which often excites lateral motion at the surfaces of a defect. This motion induces frictional heating and ... |
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| Microstructure and Properties of Cast Ingots of Al-Zn-Mg-Cu Alloys Modified with Sc and Zr |
OCT 2004 |
25 pages |
| Authors:
O. N. Senkov; R. B. Bhat; S. V. Senkova; D. Schloz; UES INC DAYTON OH
|
| The effect of combined additions of Sc and Zr on the microstructure and tensile properties of the direct chill (DC) cast ingots of developmental Al- Zn-Mg-Cu alloys has been evaluated in this work. The properties in both the longitudinal and transverse directions of the cast ingots were determined in as- cast and cast plus heat-treated conditions, at room and cryogenic temperatures. Extensive microstructural evaluation was carried out using optical and ... |
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| Advanced Methods for Highly-Portable Field Repair Welding and Assessing Phase Stability and Aging of Alloys in Service |
03 SEP 2004 |
28 pages |
| Authors:
David L. Olson; Yeong-Do Park; COLORADO SCHOOL OF MINES GOLDEN DEPT OF METALLURGICAL ENGINEERING
|
| New welding consumables and practices for weld repair are being investigated. Special attention was given to the repair of light metals (aluminum and magnesium alloys). Metal powder filled cored aluminum wires to be used with microwire GMA spool hand held guns were being developed. The use of strip-to-wire mill to make powder metal-cored wires was being perfected as an effective methodology for making specialty alloy welding consumable wires. These wires ... |
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| Hole Growth Equation Related to Al-1100 Witness Plates |
AUG 2004 |
|
| Authors:
Yves Baillargeon; Cynthia Lalanne; DEFENCE RESEARCH AND DEVELOPMENT CANADAVALCARTIER (QUEBEC)
|
| This memorandum presents a mathematical model to assess fragment hole area based on projectile impacting a target as a function of its velocity. Fragment Simulating Projectiles (FSP) of different mass and velocity were used for experimental trials with witness packs (WP). The analyses were performed with the latest versions of DeCaM (Debris Characterization and Modelling software) and WPAS (Witness Pack Analysis System). The hole growth equation developed is linear and ... |
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| Effect of Surface Treatments on Electron Beam Freeform Fabricated Aluminum Structures |
AUG 2004 |
11 pages |
| Authors:
Karen M. Taminger; Robert A. Hafley; David T. Fahringer; Richard E. Martin; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CENTER
|
| Electron beam freeform fabrication (EBF3) parts exhibit a ridged surface finish typical of many layer-additive processes. Thus, post-processing is required to produce a net shape with a smooth surface finish. High speed milling, wire electrical discharge machining (EDM), electron beam glazing, and glass bead blasting were performed on EBF(3)-built 2219 aluminum alloy parts to reduce or eliminate the ridged surface features. Surface roughness, surface residual stress state, and microstructural characteristics ... |
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| Metallurgical Examination of a Failed AH-64D Pilot Cyclic Stick (Part Number 7-511512001-3) |
AUG 2004 |
34 pages |
| Authors:
Victor Champagne; Scott Grendahl; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| The U.S. Army Research Laboratory was requested by the U.S. Aviation and Missile Command (AMCOM) to examine a pilot cyclic stick (part number P/N 7- 511512001-3) and a copilot cyclic stick (P/N 7-511515001-3) taken from an AH-64D Apache helicopter, which crashed at Ft. Rucker, AL. The pilot stick was received broken into two pieces while the copilot stick was cracked, but not completely separated. While this investigation focused on the ... |
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| Adequate Protection Systems for Reduction of Wear on Tornado Aircraft |
01 JUN 2004 |
|
| Authors:
Franco Bagnoli; AIR FORCE FLIGHT TEST CENTER POMEZIA (ITALY) DEPT OF CHEMISTRY
|
| The use in service life of the Tornado aircraft showed several areas subjected to wear. Due to its design some of them include, for example, the attachment for the variable wings, the related components, and the flap tracks; some concern the taileron and the air intake ducts. According to this, the affected interfaces of different materials and the structural components have been protected with appropriate coatings to maintain the operability ... |
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| Workshop Report: Linking Processing to Performance through Microstructure |
MAY 2004 |
5 pages |
| Authors:
EUROPEAN OFFICE OF AEROSPACE RESEARCH AND DEVELOPMENT FPO NEW YORK 09510
|
| This report summarizes the Linking Processing to Performance through Microstructure Workshop, which was held 2-5 May 2004 in Freiburg, Germany. The objective of this workshop was to review recent European advances in the characterization and representation of microstructure and how they can be used in linking processing and property models. Topics addressed included new approaches to three-dimensional quantification of material structure across all relevant length scales and the use of ... |
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| Sol-Gel Technology for Low-VOC, Nonchromated Adhesive Bonding Applications SERDP; Project PP-1113, Task 1 |
01 APR 2004 |
163 pages |
| Authors:
James J. Mazza; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| A government-industry team, primarily funded by the Strategic Environmental Research and Development Program (SERDP) under Project PP-1113, developed new environmentally friendly metal surface preparations for adhesive bonding applications. These processes were based on waterborne, nonchromated chemistry developed by Boeing and designated Boegel-EPII. Preparation of aluminum, titanium, and stainless steel adherends was investigated for on- component repair as well as original equipment manufacturer (OEM) applications. The bulk of the work was ... |
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| Aircraft Carrier Exposure Testing of Aircraft Materials |
09 JAN 2004 |
21 pages |
| Authors:
Eui W. Lee; N. Abourialy; J. Kozol; NAVAL AIR WARFARE CENTER AIRCRAFT DIV PATUXENT RIVER MD
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| Previous studies have demonstrated that the aircraft carrier environment in the western Pacific Ocean is far more severe than other marine or industrial environments. Laboratory accelerated tests do not necessarily reproduce the real time corrosion behavior of materials on board an aircraft carrier on deployment. Test and control specimens were affixed on exposure racks and installed on aircraft carriers to compare adhesive bonding primers for aluminum and to determine the ... |
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| Corrective Measures to Restore Corrosion Resistance Following Friction Stir Welding |
2004 |
21 pages |
| Authors:
ROCKWELL SCIENTIFIC CO THOUSAND OAKS CA
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| Friction stir welding (FSW) is a solid state joining process invented at TWI in 1991. This technology makes it possible to join aluminum alloys, which are difficult or impossible to weld by conventional techniques.(1-7) A schematic illustration of the FSW process is shown in Figure 1. To friction stir weld either a butt or lap joint, a specially designed cylindrical tool is rotated and plunged into the joint line. The ... |
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| HVOF Application of Nickel and Nickel Alloy to Tungsten Heavy Alloy Jacketed Penetrators |
NOV 2003 |
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| Authors:
John V. Kelley; Russell Kilbane; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
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| In recent years, there has been an increased desire to replace depleted uranium (DL) anti-armor penetrators with tungsten heavy alloy (WHA) penetrators. However, the ballistic performance of WHA does not compare with that of DL). Many methods of improving the ballistic properties of tungsten have been explored. One recent method includes jacketing a long thin core of WHA with a more ductile metal. This report examines the use of thermal-sprayed, ... |
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| Grain Size Control in AA5083 by Thermomechanical Processing (TMP): The Role of Dispersed Particles |
SEP 2003 |
109 pages |
| Authors:
Ramiro E. Orellano Jr; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF MECHANICAL AND ASTRONAUTICAL ENGINEERING
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| Superplasiticity in Aluminum alloys allows for the economical forming of components of complex shapes while retaining the high-strength and stiffness- to-weight ratios characteristic of alloys used in automotive, aerospace and military applications. Superplastic materials require fine grains with high- angle boundaries having resistance to failure by cavitation. This study was designed to achieve improved control of microstructure of Continuously Cast (CC) AA 5083 utilizing the Particle Stimulated Nucleation (PSN) model ... |
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| Mechanically Milled Iron Alloys for High-Temperature Magnetic and Structural Applications |
29 AUG 2003 |
13 pages |
| Authors:
Anthony S. Arrott; Carey E. Stronach; David R. Noakes; VIRGINIA STATE UNIV PETERSBURG
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| Mechanically-milled alloys of iron with cobalt ("Hyperco")and aluminum have been fabricated with a puck-and-saucer mill, and have been studied with the bulk magnetization, differential scanning spectrometry, neutron scattering and muon spin rotation techniques. One as-yet-unresolved problem is that of compaction. Two major discoveries concerning iron-aluminum alloys were made during this reporting period, inverse melting, and the presence of incommensurate static spin-density waves. A laboratory for preparation and characterization of magnetically-ordered ... |
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| Low Temperature Active Joining of Structural and Electronic Composites |
15 JUL 2003 |
64 pages |
| Authors:
Ronald W. Smith; Travia Nelson; MATERIALS RESOURCES INTERNATIONAL LANSDALE PA
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| This report covers the technical work conducted under contract DASG60-00-C-0056. MRi has successfully completed an evaluation of its active solder joining technology (S-Bond) for joining lightweight aluminum matrix ceramic composites (Al-MMC), such as Al-SiC. This joining technology has been shown to have application in a range of applications for space platform structures and electronics, where Al-MMC's are finding application. S-Bond joining has joint capability from 190 - 350 C, depending ... |
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Reports by Keyword(s)
ALUMINUM ALLOYS
