Application of Coatings for Electromagnetic Gun Technology

1993 ◽  
Vol 316 ◽  
Author(s):  
M. A. Otooni ◽  
A. Graf ◽  
G. Colombo ◽  
J. Conrad ◽  
K. Sridharan ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Research Effort ◽  
Ion Beam ◽  
Preliminary Investigation ◽  
Plasma Source ◽  
Auger Spectroscopy ◽  
Transmission Electron ◽  
Spark Erosion ◽  
Plasma Source Ion Implantation ◽  
Extensive Degradation

ABSTRACTCopper and aluminum are extensively used in various parts of the Electromagnetic (EM) Gun systems. Copper is used in the design of the railgun because it has favorable electrical and thermal properties. Aluminum is used for armature and sabot fabrication because of it is light weight and has favorable thermal properties. Extensive degradation of the copper rail and aluminum armature occurs owing to the severe heating and thermomechanical deformation of these components during operation of the EM gun. In this research effort, several modification techniques were used to protect the rail and armature materials from these degradation processes. These include application of Plasma Source Ion Implantation (PSII) and Ion Beam Enhanced Deposition (IBED) . By using these techniques, the copper rails and aluminum armatures were coated with TiN and TaN. Several characterization techniques were used to assess the chemical,mechanical and other properties of these modified surfaces. Optical Microscopy, Scanning and Transmission Electron Microscopy, and Scanning Auger Spectroscopy techniques were also used. Microhardness measurements have also been performed. From the results of this preliminary investigation, it has been concluded that the surface properties of the coated rail and armature materials have been improved and the extent of wear and spark erosion from these surfaces has been reduced.

Materials Science Issues of Plasma Source Ion Implantation

1995 ◽  
Vol 396 ◽  
Author(s):  
M. Nastasi ◽  
A.A. Elmoursi ◽  
R.J. Faehl ◽  
A.H. Hamdi ◽  
I. Henins ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Materials Science ◽  
Ion Beam ◽  
Value Added ◽  
Plasma Source ◽  
Industrial Applications ◽  
Plasma Source Ion Implantation ◽  
Potential Applications ◽  
Surface Modification Techniques ◽  
Wear Coatings

AbstractIon beam processing, including ion implantation and ion beam assisted deposition (IBAD), are established surface modification techniques which have been used successfully to synthesize materials for a wide variety of tribological applications. In spite of the flexibility and promise of the technique, ion beam processing has been considered too expensive for mass production applications. However, an emerging technology, Plasma Source Ion Implantation (PSII), has the potential of overcoming these limitations to become an economically viable tool for mass industrial applications. In PSII, targets are placed directly in a plasma and then pulsed-biased to produce a non-line-of-sight process for intricate target geometries without complicated fixturing. If the bias is a relatively high negative potential (20-100kV) ion implantation will result. At lower voltages (50-1200V), deposition occurs. Potential applications for PSII are in low-value-added products such as tools used in manufacturing, orthopedic devices, and the production of wear coatings for hard disk media. This paper will focus on the technology and materials science associated with PSII.

Improved Tribological Behavior of Boron Implanted Ti-6A1-4V

1997 ◽  
Vol 505 ◽  
Author(s):  
N. P. Baker ◽  
K. C. Walter ◽  
M. Nastasi
Keyword(s):  
Wear Resistance ◽  
Depth Profile ◽  
Surface Hardness ◽  
Plasma Source ◽  
Wear Coefficient ◽  
Ion Energy ◽  
Depth Profiles ◽  
Transmission Electron ◽  
Plasma Source Ion Implantation ◽  
Boron Implantation

ABSTRACTPrevious research has compared the mechanical properties of Ti6A14V implanted with nitrogen using the plasma source ion immersion process and Ti6A14V implanted with boron using the beamline process [1]. Although the nitrogen implanted Ti6A14V had superior wear resistance it was concluded that the wear resistance of boron implanted Ti6AI4V might be improved to comparable levels if boron were implanted at lower energies to increase the concentration of boron at the surface. Boron implantation of Ti6A14V has been conducted at combinations of 32 and 40 keV to supplement that done previously at 75 keV. Shallower boron depth profiles with higher B-concentrations in the Ti64 surface have been obtained by tailoring the combinations of ion energy and dose. This work used three different ion energy and dose combinations of 4×1017 B-at/cm2 at 40 keV plus 2×1017 B-at/ cm2 at 32 keV, 4×1017 B-at/cm2 at 40 keV, and 4×1017 B-at/cm2 at 32 keV plus 2×1017 B-at/ cm2 at 40 keV. Comparisons are made between Ti6A14V with a shallow implanted boron depth profile, Ti6AI4V with a deeper boron depth profile and nitrogen implanted using a plasma source ion implantation process. It has been previously shown that while boron implanted Ti64 has a ~30% higher surface hardness than nitrogen implanted Ti64, the N-implantation reduced the wear coefficient of Ti64 by 25–120x, while B-implantation reduced the wear coefficient by 6.5x or less. The results show that no significant improvement is made in the wear resistance of boron implanted Ti6A14V by increasing the concentration of boron at the surface from approximately 10%to 43%. Transmission electron microscopy (TEM) and selected area diffraction (SAD) indicated the formation of crystalline TiB in the implanted surface layer. Shallower depth profiles result in reductions of the Ti6AI4V wear coefficient by 6.5x or less which is the same result obtained earlier with the deeper boron depth profile. Surface hardness of Ti6A14V with shallower boron depth profiles was improved approximately 10%compared to the results previously acquired with deeper boron depth profiles.

Ion beam assisted coating and surface modification with plasma source ion implantation

1990 ◽  
Vol 8 (4) ◽  
pp. 3146-3151 ◽  
Author(s):  
J. R. Conrad ◽  
R. A. Dodd ◽  
S. Han ◽  
M. Madapura ◽  
J. Scheuer ◽  
...  
Keyword(s):  
Surface Modification ◽  
Ion Implantation ◽  
Ion Beam ◽  
Plasma Source ◽  
Plasma Source Ion Implantation

Surface modification of aluminum and chromium by ion implantation of nitrogen with a high current density ion implanter and plasma-source ion implantation

1999 ◽  
Vol 14 (11) ◽  
pp. 4351-4357 ◽  
Author(s):  
Zoran Falkenstein ◽  
Kevin C. Walter ◽  
Michael A. Nastasi ◽  
Donald J. Rej ◽  
Nikolai V. Gavrilov
Keyword(s):  
Surface Modification ◽  
Ion Implantation ◽  
Dose Rate ◽  
Current Density ◽  
High Current Density ◽  
Ion Beam ◽  
Plasma Source ◽  
High Current ◽  
Beam Source ◽  
Plasma Source Ion Implantation

Results of ion implantation of nitrogen into electrodeposited hard chromium and pure aluminum by a high-dose ion-beam source are presented and compared to plasma-source ion implantation. The large-area, high current density ion-beam source can be characterized, with respect to surface modification use, by a uniform emitted dose rate in the range of 1016 to 5 × 1017 N cm−2 min−1 over an area of <100 cm2 and with acceleration energies of 10–50 keV. The implantation range and retained dose (measured using ion-beam analysis), the surface hardness, coefficient of friction, and the change in the wear coefficient (measured by nanohardness indentation and pin-on-disk wear testing) that were obtained with an applied dose rate of ∼1.7 × 1017 N cm−2 min−1 at 25 kV are given, and they are compared to results obtained with plasma-source ion implantation.

Production of Diamond-Like Carbon Films by Plasma Source Ion Implantation

1992 ◽  
Vol 270 ◽  
Author(s):  
Ling Xie ◽  
Frank J. Worzala ◽  
John R. Conrad ◽  
Richard A. Dodd
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Implantation ◽  
Plasma Source ◽  
Carbon Films ◽  
Composition Analysis ◽  
Diamond Like Carbon ◽  
Chemical Compositions ◽  
Transmission Electron ◽  
Plasma Source Ion Implantation

ABSTRACTIn addition to being successfully used for ion implantation, the plasma source ion implantation (PSII) technique has been used to produce diamond-like carbon films. Homogeneous, adherent films were obtained on silicon and stainless steel substrates under 2 kV pulse bias voltages and 50 mtorr methane plasma pressure. Chemical composition analysis was made using Auger electron microscopy. Fretting wear tests and scratch tests were performed to study the tribological and adherent properties. Cross sectional TEM samples were prepared. The interfacial microstrucutres and chemical compositions were analyzed using transmission electron microscopy and scanning transmission electron microscopy.

The Microstructure of Nickel Oxide Scales

1981 ◽  
Vol 39 ◽  
pp. 86-87
Author(s):  
M. T. Tinker ◽  
L. W. Hobbs
Keyword(s):  
Electron Microscopy ◽  
Nickel Oxide ◽  
Ion Beam ◽  
Oxide Scales ◽  
Nickel Substrate ◽  
Outward Diffusion ◽  
Transmission Electron ◽  
Nickel Substrates ◽  
Nickel Base ◽  
Technological Interest

There is considerable technological interest in oxidation of nickel because of the importance of nickel-base superalloys in high-temperature oxidizing environments. NiO scales on nickel grow classically, by outward diffusion of nickel through the scale, and are among the most studied of oxidation systems. We report here the first extensive characterization by transmission electron microscopy of nickel oxide scales formed on bulk nickel substrates and sectioned both parallel and transversely to the Ni/NiO interface.Electrochemically-polished nickel sheet of 99.995% purity was oxidized at 1273 K in 0.1 MPa oxygen partial pressure for times between 5 s and 25 h. Parallel sections were produced using a combination of electropolishing of the nickel substrate and ion-beam thinning of the scale to any desired depth in the scale. Transverse sections were prepared by encasing stacked strips of oxidized nickel sheet in epoxy resin, sectioning transversely and ion-beam thinning until thin area spanning one or more interfaces was obtained.

Nuclear Reactions in Deuterium Titanium

1990 ◽  
Vol 48 (2) ◽  
pp. 134-135
Author(s):  
D.M. Vanderwalker
Keyword(s):  
Nuclear Reactions ◽  
Ion Beam ◽  
Exothermic Reaction ◽  
Pure Titanium ◽  
Fundamental Interest ◽  
Transmission Electron ◽  
Iodide Titanium ◽  
A Cell ◽  
After Hours ◽  
Quantity Of Heat

There is a fundamental interest in electrochemical fusion of deuterium in palladium and titanium since its supposed discovery by Fleischmann and Pons. Their calorimetric experiments reveal that a large quantity of heat is released by Pd after hours in a cell, suggesting fusion occurs. They cannot explain fusion by force arguments, nor can it be an exothermic reaction on the formation of deuterides because a smaller quantity of heat is released. This study examines reactions of deuterium in titanium.Both iodide titanium and 99% pure titanium samples were encapsulated in vacuum tubes, annealed for 2h at 800 °C. The Ti foils were charged with deuterium in a D2SO4 D2O solution at a potential of .45V with respect to a calomel reference junction. Samples were ion beam thinned for transmission electron microscopy. The TEM was performed on the JEOL 200CX.The structure of D charged titanium is α-Ti with hexagonal and fee deuterides.

A TEM study of the interface between organic matrix and aragonite in a biological hard tissue, nacre

1992 ◽  
Vol 50 (2) ◽  
pp. 1024-1025
Author(s):  
Jun Liu ◽  
Katie E. Gunnison ◽  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Mechanical Properties ◽  
Ion Beam ◽  
Laminated Composite ◽  
Organic Matrix ◽  
Pearl Oyster ◽  
Interfacial Structure ◽  
Interfacial Region ◽  
Thin Sections ◽  
Organic Layers ◽  
Transmission Electron

The interfacial structure between the organic and inorganic phases in biological hard tissues plays an important role in controlling the growth and the mechanical properties of these materials. The objective of this work was to investigate these interfaces in nacre by transmission electron microscopy. The nacreous section of several different seashells -- abalone, pearl oyster, and nautilus -- were studied. Nacre is a laminated composite material consisting of CaCO3 platelets (constituting > 90 vol.% of the overall composite) separated by a thin organic matrix. Nacre is of interest to biomimetics because of its highly ordered structure and a good combination of mechanical properties. In this study, electron transparent thin sections were prepared by a low-temperature ion-beam milling procedure and by ultramicrotomy. To reveal structures in the organic layers as well as in the interfacial region, samples were further subjected to chemical fixation and labeling, or chemical etching. All experiments were performed with a Philips 430T TEM/STEM at 300 keV with a liquid Nitrogen sample holder.

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