| Analysis of Shock and High-Rate Data for Ceramics: Equation of State Properties and Fragmentation in the Ballistic Environment |
01-May-2009 |
64 pages |
| Authors:
Dennis E Grady; APPLIED RESEARCH ASSOCIATES INC ALBUQUERQUE NM
|
 | The project effort reported on here is a continuing study undertaken to collect, survey, analyze and model shock wave, and other related high-rate and supporting data, available for candidate armor ceramics with emphasis on response in the ballistic environment. Ceramics considered here include the various light metal-nonmetal compounds selected by the Army for consideration such as silicon carbide and aluminum oxide, as well as other ceramics, glass ceramics and glasses ... |
|
| Investigation of Plasma Spray Coatings as an Alternative to Hard Chrome Plating on Internal Surfaces |
14 SEP 2006 |
180 pages |
| Authors:
Keith O. Legg; Bruce D. Sartwell; Jean-Gabriel Legoux; Montia Nestler; Christopher Dambra; Daming Wang; John Quets; Paul Natishan; Philip Bretz; Jon Devereaux; NAVAL RESEARCH LAB WASHINGTON DC
|
| Hard chromium electroplating is extensively used by aircraft manufacturers and military maintenance depots to provide wear and/or corrosion resistance or to restore dimensional tolerance to components. However, chrome plating utlizes hexavalent chromium, which is a highly toxic carcinogen, with increasingly stringent government regulations making it more expensive for DoD. This document constitutes the final report on an investigation of deposition of coatings using miniature plasma spray guns that could replace ... |
|
| Spall Strength of Tungsten Carbide |
SEP 2004 |
28 pages |
| Authors:
Dattatraya P. Dandekar; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Spall strength of a hot-pressed tungsten carbide manufactured by Cercom Inc. referred to as CER-WC. is determined by performing plane shock wave experiments as a function of shock-induced compressive stress and its duration. Shock-induced stress varied between 3.5 and 24 GPa. The duration of shock- induced stress. i.e.. pulse with. ranged from 0.35 to 1.13 mus. These experiments showed that CER-WC retained substantial spall strength to 24 GPa. i. e.. ... |
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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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| Tribology-Related Behaviour of Coated Titanium Ball Screw Mechanisms under Thermal-Vacuum Conditions |
01 JUN 2004 |
12 pages |
| Authors:
Sandro Corradi; Mario Marchetti; Fabio Mazza; UNIVERSITA DEGLI STUDI LA SAPIENZA ROME (ITALY)
|
| Grade 5 Titanium telescopic ball screws have been tested under thermal-vacuum conditions in order to verify performances during on-orbit functioning. A solid multilayer film of Tungsten Carbide/Carbon (WC/C) was deposited on screw surfaces as a lubricant and was then compared with the case of no lubrication, which presently appears promising for many mechanisms. In order to compare experimental results, traditional stainless steel (AISI 4140) mechanisms were also tested and analyzed. ... |
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| Fracture and Residual Characterization of Tungsten Carbide Cobalt Coatings on High Strength Steel |
MAY 2003 |
9 pages |
| Authors:
Donald S. Parker; OAK RIDGE NATIONAL LAB TN
|
| Tungsten carbide cobalt coatings applied via high velocity oxygen fuel thermal spray deposition are essentially anisotropic composite structures with aggregates of tungsten carbide particles bonded with both amorphous and crystalline cobalt phases. X-ray diffraction was used to characterize the residual stresses within the coatings to understand the crack initiation and propagation behavior of samples subjected to axial fatigue loads. Diffraction was also used to establish a baseline stress state of ... |
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| Thermophysical Properties and Phase Equilibria of Materials Systems |
27 JUN 2002 |
5 pages |
| Authors:
R. R. Reeber; D. Brenner; K. Wang; John Prater; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| The objective is to improve thermal expansion, specific heat, molar volume, and bulk moduli predictions at the highest temperatures and pressures. In those regions experiments are difficult and data is often marginally reliable. In a series of papers, we have developed models for predicting these properties for a wide range of metals, ceramics and semiconductors. By considering the influence of thermal defects on thermal expansion it has been possible to ... |
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| Compressor Impeller Erosion Resistant Surface Treatment |
09 OCT 2000 |
33 pages |
| Authors:
Michael A. Riley; SURFACE TREATMENT TECHNOLOGIES INC GLENBURNIE MD
|
| Electro-spark alloyed ?ESA) surfaces were developed as an erosion barrier for Ti-6-4 impellers on shaft driven compressors (SDCs). Coatings based on tungsten carbide tantalum carbide. titanium carbide all with a cobalt matrix were evaluated for high velocity particle erosion in conventional wear test studies as well as wind tunnel testing. In both cases the coating survived erosion by alumina and silica sand ranging in size ... |
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| Advanced Nanoscale Coatings with Plasma Spray |
APR 2000 |
33 pages |
| Authors:
David G. Atteridge; Martin Becker; Graham A. Tewksbury; Milton Scholl; OREGON GRADUATE INST BEAVERTON
|
| The Oregon Graduate Institute was originally charged with assessing the potential of using plasma spraying techniques to produce thermal spray coatings consisting of tungsten carbide (WC) particles in a cobalt (Co) matrix (WC-Co). The WC particles of interest in this study were those with size on the nanometer scale embedded in a Co matrix. A secondary research charter developed as this program proceeded was the ... |
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| A Ceramic Armor Material Database |
JAN 1999 |
240 pages |
| Authors:
T. J. Holmquist; A. M. Rajendran; D. W. Templeton; K. D. Bishnoi; TACOM RESEARCH DEVELOPMENT AND ENGINEERING CENTER WARREN MI
|
| This report compiles and documents a Ceramic Armor Material Database. Experimental data obtained from numerous journals and conference proceedings, by researchers of various disciplines, covering over thirty years are documented in this report. The data include nine different ceramic materials. The ceramics are Silicon Carbide, Boron Carbide, Titanium Diboride, Aluminum Nitride, Silicon Nitride, Aluminum Oxide (85% pure), Aluminum Oxide (high purity), Tungsten Carbide and Glass. For each ceramic material, experimental ... |
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| Fabrication of a Monolithic Single-Crystal Silicon Inner Cone Substrate for the Roma Program |
SEP 96 |
15 pages |
| Authors:
Frank Groark; TRW INC REDONDO BEACH CA
|
| Previous high energy laser mirrors were made of metals such as molybdenum, copper and tungsten carbide. These mirrors required active heat exchanger coolant systems to maintain the desired surface figure and were complicated and costly to manufacture. The successful use of uncooled, single crystal silicon mirrors for beam transfer optics in high energy lasers has demonstrated the feasibility of uncooled resonator mirrors. The Resonator Optics Material Assessment (ROMA) program surveyed ... |
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| Materials Research Society Symposium Proceedings. Volume 434. Layered Materials for Structural Applications. April 8-11, 1996, San Francisco, California |
APR 96 |
|
| Authors:
J. J. Lewandowski; C. H. Ward; M. R. Jackson; W. H. Hunt Jr; MATERIALS RESEARCH SOCIETY PITTSBURGH PA
|
| Layered materials and systems based on metallic, intermetallic, polymeric and ceramic constituents are becoming increasingly important to meet the structural requirements of current and future high-performance products. In response to various research and development activities in these areas, Symposium was organized to cover a range of topics dealing with layered materials for structural applications and was supported by contributions from The Air Force Office of Scientific Research and Office of ... |
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| Diamond-Coated Versus Conventional Bits for Rotary Cutter Head Equipment |
JUL 95 |
47 pages |
| Authors:
Roy L. Campbell Sr.; G. S. Wong; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS STRUCTURES LAB
|
| The objectives of this research were (a) to quantitatively demonstrate the diamond-coated-bit, culler-boom tool as an expedient, cost- effective, concrete- removal method for the rehabilitation of locks, dams, tunnels, and other similar structures and (b) to provide real production and cost data for comparison with other removal methods. The end product of this research was to be a new diamond-coated-bit, culler-boom tool that would give U. S. contractors a competitive ... |
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| Diamond Growth on Carbide Surfaces Using a Selective Etching Technique |
JUL 93 |
30 pages |
| Authors:
K. J. Grannen; R. P. Chang; NORTHWESTERN UNIV EVANSTON IL DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| Microwave plasma-enhanced chemical vapor deposition of diamond films on silicon carbide and tungsten carbide (with 6% cobalt) surfaces using fluorocarbon gases has been demonstrated. No diamond powder pre-treatment is necessary to grow these films with a (100) texture. The diamond films are characterized by scanning electron microscopy and Raman spectroscopy. The proposed nucleation and growth mechanism involves concurrent etching of the non- carbon component by atomic fluorine and deposition of ... |
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| Thermomechanical Contact Phenomena and Wear of Sliding Components |
31 JUL 89 |
68 pages |
| Authors:
Francis E. Kennedy Jr.; Beda M. Espinoza; Susanne M. Pepper; Lin Tang; THAYER SCHOOL OF ENGINEERING HANOVER N H
|
| The objectives of this investigation were to better understand the tribological behavior of ceramic-coated rings sliding against carbon graphite and thermocracking that occurs with some of the ceramic coatings. Sliding wear tests were conducted on Inconel 625 substrates coated with four different hare materials: chromium oxide, chromium carbide, titanium nitride, and tungsten carbide. Tests were also run to determine the corrosion behavior of the ceramic- coated rings in seawater. Surface ... |
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| Thermomechanical Contact Phenomena and Wear of Sliding Seal Components |
30 MAR 88 |
40 pages |
| Authors:
Francis E. Kennedy Jr.; Beda M. Espinoza; Susanne M. Pepper; THAYER SCHOOL OF ENGINEERING HANOVER N H
|
| The objectives of this investigation were to better understand the tribological behavior of ceramic-coated rings sliding against carbon graphite and the thermocracking that occurs with some of the ceramic coatings. Sliding wear tests were conducted on Inconel 625 substrates coated with four different hard materials: chromium oxide, chromium carbide, titanium nitride, and tungsten carbide. Tests were also run to determine the corrosion behavior of the ceramic- coated rings in seawater. ... |
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| Surface Chemistry of Transition Metal Carbides: A Theoretical Analysis |
JUL 87 |
|
| Authors:
Susan A. Jansen; Roald Hoffmann; CORNELL UNIV ITHACA NY LAB OF ATOMIC AND SOLID STATE PHYSICS
|
| Extended Huckel tight binding calculations have been employed to analyze the interactions of oxygen, carbon monoxide and methanol with the (100) and (111) faces of a representative rocksalt carbide, TiC. The (111) face have been experimentally shown to be the most active toward the adsorption, dissociation or decomposition of adsorbates, whereas the (100) face demonstrates very little activity. Calculations suggest that the differential reactivity of the two faces is the ... |
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| Analysis of Composite Shrink Fits - Tresca Material |
JUL 87 |
|
| Authors:
Peter C. Chen; ARMY ARMAMENT RESEARCH, DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET WEAPONS LAB
|
| A thin composite shrink fit assembly is examined herein using an elastic-plastic analysis. The ring and disk are made of different materials. Interferences large enough to induce plastic deformations in the ring are considered. The ring material is assumed to be a linear strain-hardening material that obeys Tresca's yield condition and the associated flow rule. The explicit expressions for stresses and deformations in the shrink fit assembly have been obtained. ... |
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| Thermomechanical Contact Phenomena and Wear of Sliding Components |
27 MAR 87 |
53 pages |
| Authors:
Francis E. Kennedy Jr.; Syed Z. Hussaini; Beda M. Espinoza; THAYER SCHOOL OF ENGINEERING HANOVER N H
|
| The objectives of this work have been to gain a better understanding of the wear of solid ceramic and ceramic-coated metallic seal rings in contact with carbon graphite and to determine the solid/solid contact conditions responsible for that wear. Ring-on-ring tests were run under dry conditions (no sealed fluid) with carbon graphite seal rings sliding against two types of hard seal face materials, monolithic silicon carbide and metallic materials coated ... |
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| Ion Implantation Manufacturing Technology Project |
JAN 87 |
|
| Authors:
SPIRE CORP BEDFORD MA
|
| The objective of the NRL MANTECH Program was to design, build, and operate a high-throughput ion implantation facility. This facility is to be used to demonstrate the transfer of implantation technology to industrial pilot production conditions. The program consisted of three phases, each intended to involve one year of effort. The first involved design of a vacuum end station with compatible high-throughput workpiece-handling fixtures. Phase 2 consisted of fabrication of ... |
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| Numerical Study of Material Properties of Submerged Elastic Objects Using Resonance Response |
MAY 86 |
|
| Authors:
M. F. Werby; G. J. Tango; NAVAL OCEAN RESEARCH AND DEVELOPMENT ACTIVITY NSTL STATION MS
|
| Scattering from many fluid loaded elastic solid objects yields echo responses that are characteristic of rigid scatters, with the exception of narrow resonance regions. These resonances are related to Rayleigh type surface disturbances and thus are determined by the material properties of the scatter. The purpose of this study is to predict resonances for several representative elastic materials to ascertain material properties that can be associated with resonance phenomena. This ... |
|
| Padlock Shackle. |
31 DEC 1985 |
|
| Authors:
David Goldstein; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A padlock shackle made of an inner core of ductile nickel-titanium alloy, an outer casing of hardened stainless steel, and an intermediate layer of a composite of tungsten carbide particles in a nickel-titanium alloy matrix which is bonded to the nickel-titanium alloy core and mechanically bonded to the stainless outer casing. (Patents) |
|
| Acoustical Scattering from an Elastic Sphere in Water: Surface Wave Glory, Resonances, and the Sommerfeld-Watson Transformation for Amplitudes |
AUG 85 |
74 pages |
| Authors:
K. L. Williams; WASHINGTON STATE UNIV PULLMAN DEPT OF PHYSICS
|
| Scattering of acoustic waves from fluid-load elastic spheres with 10 < ka < 100 (where k is the wavenumber of the acoustic wave in the liquid and a the radius of the sphere) is studied, The main emphasis is on understanding the scattered pressure near backscattering. By carrying out a Sommerfeld-Watson Transformation (SWT) it is shown that this pressure includes contributions from specular reflection, transmitted bulk waves, and surface waves. ... |
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| Improved Lifetime High Voltage Switch Electrode |
28 JUN 85 |
|
| Authors:
W. Halverson; SPIRE CORP BEDFORD MA
|
| In this Phase I Small Business Innovation Research (SBIR) program, preliminary tests of ion implantation to increase the lifetime of spark switch electrodes have indicated that a 185 keV carbon ion implant into a tungsten- copper composite has reduced electrode erosion by a factor of two to four. Apparently, the thin layer of tungsten carbide (WC) has better thermal properties than pure tungsten; the WC may have penetrated into the ... |
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| Calibration Method for Acoustic Scattering Measurements Using a Spherical Target. |
09 OCT 1984 |
|
| Authors:
L. R. Dragonette; L. J. Frank; S. K. Numrich; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| This patent discloses a method for calibrating acoustic backscattering instrumentation utilizing a spherical body as a standard target. A spherical body made of high specific acoustic impedance material, such as tungsten carbide, is positioned a given distance from a source/receiver transducer which is energized to produce a short acoustic pulse directed toward the sphere. Acoustic signals reflected from the sphere are detected by the transducer and processed in the time ... |
|
| Laser Mirror and Method of Fabrication. |
21 FEB 1984 |
|
| Authors:
J. G. Gowan; K. R. Shillito; DEPARTMENT OF THE AIR FORCE WASHINGTON DC
|
| An improved laser mirror and heat exchanger and method of fabrication is described which comprises, in a preferred embodiment thereof, a carbon/carbon fiber matrix substrate having deposited thereon a transitional composition layer of carbon and tungsten carbide, and one or more layers of tungsten or tungsten carbide. These layers define a desired network of coolant passageways formed by depositing a low melting point material, such as antimony, in a raised ... |
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| Electrodeposition of Refractory Metal Carbides. |
07 FEB 1984 |
|
| Authors:
K. H. Stern; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A refractory metal carbide coating is electrodeposited onto an object, using a bath containing an alkali fluoride melt, an alkali carbonate dissolved in the melt, a refractory metal-containing compound also dissolved in the melt, and an anode composed of that refractory metal. The object to be coated is immersed into the bath as the anode, and a voltage is applied until the coating obtains the desired thickness. By this process, ... |
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| Rapid Runway Repair Program Subtask 1.07 - Rapid Concrete Cutting |
JUN 1983 |
|
| Authors:
R. K. Moats; F. D. Wang; William Dears; G. G. Yie; BDM CORP MCLEAN VA
|
| Two concrete-cutting technologies utilizing high-pressure waterjets have been investigated to assess their feasibility in achieving rapid cutting rates (30 sq ft/min) to facilitate bomb damage repair to runways. The current cutting rate of abrasive waterjets was established as 0.25 sq ft/min for a 60 hp system. Present scaling information indicates that for the near term the technology cannot feasibly achieve the desired cutting rate without a major technical breakthrough. Data ... |
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| Fuel Valve. |
01 FEB 1983 |
|
| Authors:
Raymond L. Williams; DEPARTMENT OF THE AIR FORCE WASHINGTON DC
|
| This invention is a spring-biased valve assembly that will not corrode, gall, or otherwise wear, and that is for use in selectively controlling a flow of liquid fuel. The valve assembly, in its preferred embodiment, is eminently suitable for use in a gas turbine engine to keep the fuel manifold of the afterburner full when not operating, and to effectuate equal distribution of the fuel flow to a plurality of ... |
|
| Electrodeposition of Refractory Carbide Coatings |
30 DEC 1982 |
|
| Authors:
K. H. Stern; NAVAL RESEARCH LAB WASHINGTON DC
|
| A novel method for electrodepositing refractory carbide coatings from molten salts is described. It consists of the simultaneous reduction of the appropriate metal species dissolved in the ternary LiF-NaF-KF eutectic and carbonate dissolved in the same melt. The metal and carbon deposit on the cathode where they react to form the carbide. The coatings are hard, abrasion resistant, and resist oxidation in air to 500 C. Carbides of tantalum and ... |
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| High Speed Metal Removal |
OCT 1982 |
|
| Authors:
Richard F. Pugh; Raymond F. Pohl; TEXTRON INC SPRINGFIELD VT JONES AND LAMSON DIV
|
| Four types of steel (AISI 1340, 4140, 4340, and HF-1) which are commonly used in large caliber projectile manufacture were machined at different hardness ranges representing the as-forged and the heat-treated condition with various ceramic tools using ceramic coated tungsten carbide as a reference. Results show that machining speeds can be increased significantly over current practice using the present available tooling. |
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| Ultra-High Surface Speed for Metal Removal, Artillery Shell |
JUL 1981 |
|
| Authors:
Richard F. Pugh; Michael R. Walsh; Raymond F. Pohl; TEXTRON INC SPRINGFIELD VT JONES AND LAMSON DIV
|
| Four types of steel (AISI 1340, 4140, 4340, and HF-1) which are commonly used in large caliber projectile manufacture were machined with five types of tools at different hardness ranges representing the as-forged and the heat-treated condition. Results show that machining speeds can be increased significantly over current practice using the present available tooling. |
|
| Particle Impact Damage in Ceramics. |
APR 1981 |
60 pages |
| Authors:
D. A. Shockey; J. H. Giovanola; SRI INTERNATIONAL MENLO PARK CA
|
| A brief summary is given of the research performed during the first four years of a program investigating particle impact damage in ceramics; a detailed count is given of the research performed during the fifth and final year. In the first four years, hot-pressed and reaction-bonded silicon nitride, chemical-vapor-deposited zinc sulfide, and a microstructurally toughened ceramic (Si3N4-20%ZrO2) were impacted with tungsten carbide spheres 0.4 mm to 2.4 mm in diameter ... |
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| Particle Impact Damage in Ceramics. |
MAR 1981 |
|
| Authors:
D. A. Shockey; K. C. Dao; D. C. Erlich; R. L. Burback; D. R. Curran; SRI INTERNATIONAL MENLO PARK CA
|
| Impacts of tungsten carbide spheres on Si3N4 produced elastic fracture behavior (ring and cone cracks) at room temperature, but elastic-plastic fracture behavior (plastic impressions and radial cracks) at 1400 C. In contrast, no change in fracture pattern at the two temperatures was produced by impact with steel spheres. These results may be explained by the relative abilities of the impacting spheres to cause plastic flow at the impact site and ... |
|
| Abrasive Machining of Major Components |
MAY 1979 |
70 pages |
| Authors:
John Rodd; ARMY ARMAMENT RESEARCH AND DEVELOPMENT CENTER WATERVLIET NY LARGE CALIBER WEAPON SYSTEMS LAB
|
| The term 'abrasive machining' has been expressed in many ways. It is generally used to denote stock removal operations that are more economically performed by abrasive grinding methods than the more conventional means of turning or milling. The two largest fields for abrasive machining are the production of flat surfaces and form grinding from the solid. This report is concerned with the latter; grinding various complex external shapes from the ... |
|
| Interior and Terminal Ballistics of 25g Long Rod Penetrators. |
APR 1979 |
90 pages |
| Authors:
Stephen J. Bless ; DAYTON UNIV OH RESEARCH INST
|
| Techniques were developed to launch 25g (L/D = 10) rods from a 50mm propellant gun. The rods were S-7 tool steel, W-Ni-Fe alloy, and Co-bonded WC. The velocities were in the range 1.8 to 2.58 km/s. The rods were launched against 25.4mm 4340 steel plates at 0 deg and 45 deg obliquity, and four 6.35mm 2024 T3 aluminum plates. Behind-target fragment data were obtained by flash x-ray analyses, witness plate ... |
|
| Nucleation and Growth of Cracks in CVD ZnS Under Particle Impact. |
APR 1979 |
|
| Authors:
D. A. Shockey; K. C. Dao; D. R. Curran; SRI INTERNATIONAL MENLO PARK CA
|
| This research program was undertaken to identify and evaluate material properties governing fracture damage development in a laser window material under hard particle impact. The approach was to determine the sequential development of fracture damage in a ceramic in the vicinity of a particle impact site, to quantitatively assess the population of radial cracks, and to deduce crack nucleationand growth expressions and properties by correlating the damage with an appropriate ... |
|
| Localized Impact Damage in Ceramics. Theory of Elastic-Plastic Impact on Ceramics Localized Impact Damage in Transformation Toughened Zirconia. Crack Propagation and Branching in Transformation Toughened Zirconia. |
JAN 1979 |
|
| Authors:
H. P. Kirchner; D. M. Richard; R. C. Garvie; R. M. Gruver; CERAMIC FINISHING CO STATE COLLEGE PA
|
| The following are covered in this report: (1) Theory of elastic-plastic impact on ceramics; (2) Localized impact damage in transformation toughened zirconia; (3) Crack propagation and branching in transformation toughened zirconia. (Author) |
|
| New Materials for Fluorosulfonic Acid Electrolyte Fuel Cells. |
JUN 1977 |
|
| Authors:
Michael George; Stanley Januszkiewicz; ENERGY RESEARCH CORP DANBURY CONN
|
| Hydrogen-air fuel cells were evaluated with both TFMSA monohydrate and dilute TFMSA. Pressurized monohydrate cells were run at power levels comparable to phosphoric acid fuel cells under similar conditions. Fuel cells with from 25 to 60% TFMSA were evaluated at 25 and 70 C. A cell with 50% TFMSA was run for over 2,000 hours at room temperature without acid replenishment. Power densities in excess of 130mW/sq cm could be ... |
|
| Corrosion Fatigue Behavior of Coated 4340 Steel for Blade Retention Bolts of the AH-1G Helicopter. |
OCT 1976 |
|
| Authors:
Milton Levy; Joseph L. Morrossi; ARMY MATERIALS AND MECHANICS RESEARCH CENTER WATERTOWN MASS
|
| The main rotor blade bolt for the 540 helicopter rotor system of the AH-1G, UH-1C, and UH-1M helicopters is proposed to be improved by substituting plasma-sprayed tungsten carbide coating on the outer shank of the 4340 steel bolt for the present cadmium or chromium plate. This study was undertaken to determine the effects of these coating systems on the fatigue behavior of 4340 steel in environments likely to be encountered ... |
|
| Analysis of Ultrasonic Wave Scattering for Characterization of Defects in Solids. |
MAY 1976 |
39 pages |
| Authors:
e. richard cohen; ROCKWELL INTERNATIONAL THOUSAND OAKS CALIF SCIENCE CENTER
|
| Measurements have been carried out on scattering of ultrasonic waves by a solid spherical inclusion (tungsten carbide) in titanium alloy. Both direct scattering and mode-converted scattering angular distributions were measured for both shear and compressional incident waves. The scattering from an arbitrary shape was expressed in terms of an integral equation from which an improved Born approximation was developed. In this formulation, the Born approximation reduces to the Rayleigh limit ... |
|
| Localized Impact Damage in Ceramics. |
JAN 1976 |
|
| Authors:
Henry P. Kirchner; Robert M. Gruver; Craig S. Miller; CERAMIC FINISHING CO STATE COLLEGE PA
|
| Two topics are covered in this report: (1) Localized impact damage in hot pressed Si3N4 and SiC and, (2) Effect of leached surface layers on impact damage and remaining strength of Si3N4. The impact force necessary to form Hertz cracks in H.P. Si3N4 was about four times that for SiC. The Hertz cracks were characterized and the dimensions were compared with calculated values. The crack depths and the strength degradation ... |
|
| Performance Evaluation of Ceramic Materials and Aspects of Surface Preparation for Gas-Bearings. |
DEC 1975 |
|
| Authors:
Thomas J. Rockett; Peter J. Gielisse; O. B. Damani; K. Kulkarni; P. W. Smith; RHODE ISLAND UNIV KINGSTON DIV OF ENGINEERING RESEARCH AND DEVELOPMENT
|
| In the first part of this report, silicon nitride and boron carbide were the materials studied for their friction and wear properties. Boron carbide in air gave an average coefficient of friction of 0.11 + or - 0.1 but values as low as 0.03 were observed under certain conditions. Surface chemistry plays a critical role in determining the coefficient values. Wear yielded surface-active debris which became more dense to form ... |
|
| An Investigation of Nonreactive Surface Coatings for Use in Solid Propellant Arc-Image Ignition Studies. |
DEC 1975 |
|
| Authors:
R. W. Fleming; R. L. Derr; LOCKHEED PROPULSION CO REDLANDS CALIF
|
| The objective of this research program was to evaluate the feasibility of coating the propellant surface with an opaque, nonreacting material to eliminate this difficulty in interpretation of test results. The effect of the coating would be to reduce absorption of radiant energy beneath the propellant surface and provide a uniform surface absorptivity for different propellants. Radiant flux levels considered for this study were selected to indicate the effectiveness of ... |
|
| Mechanical Properties of Solid-Solution and Carbide-Strengthened Arc- Melted Tungsten Alloys |
FEB 1966 |
38 pages |
| Authors:
Peter L. Raffo; William D. Klopp; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
|
| DESIGN CRITERIA FOR ROLLING ELEMENT AIR FRAME BEARINGS FOR HIGH TEMPERATURE AND HIGH ALTITUDE USE |
APR 1963 |
93 pages |
| Authors:
Harold E. Munson; Jamshed B. Havewala; John H. Johnson; MARLIN-ROCKWELL CO JAMESTOWN NY
|
| Aircraft Control Bearings were experimentally studied to evaluate bearing design, materials, and lubricants for operation at 1200 F and 250,000 ft. altitude. Four roll design, twelve material combinations and five dry lubricants were investigated. The best design and two best material combinations (6B (Cobalt Alloy) vs 6B and CA-3 (Tungsten Carbide Cermet) vs 6B) were subjected to stresses up to 325,000 psi at the temperature and altitude. One in. diameter ... |
|
| Feasibility Study of a Multilayer Flame-Spray-Coated and a Brazed Platelet-Coated Armor Plate as a Defense against HEAT Ammunition. |
MAY 1960 |
|
| Authors:
J. M. Ingraham; M. M. Mardirosian; WATERTOWN ARSENAL LABS MA
|
|
| Developing Substitute Binders for Cobalt in WC-Co Alloys and Studying the Effect of Grain Size of WC on the Strength of WC-Co Alloys. |
30 JUN 1958 |
|
| Authors:
Harry Udin; MANLABS INC CAMBRIDGE MASS
|
|
| Investigation of Substitutes for Cobalt in WC-Co Alloys and Effect of Grain Size on the Properties of WC-Co Alloys. |
15 JUN 1955 |
|
| Authors:
P. A. Kulin; R. Jenkins; G. Robinson Jr; MANLABS INC CAMBRIDGE MASS
|
|
| A Method of Treating Ultrasonic Scattering as a Random Variable Problem, |
JUN 1952 |
|
| Authors:
Rohn Truell; WATERTOWN ARSENAL MA
|
|
Reports by Keyword(s)
TUNGSTEN CARBIDES
