Surface Modification of Electromagnetic Railgun Components

1993 ◽  
Vol 316 ◽  
Author(s):  
M. A. Otooni ◽  
A. Graf ◽  
C. Dunham ◽  
Ian Brown ◽  
Xiang Yao

ABSTRACTCopper and aluminum used for rail and armature materials in electromagnetic railgun systems undergo severe degradation during the EM gun operation. The extent of this degradation is especially severe in guns operated at high energy levels or designed for repeated firings. In an effort to improve surface properties of the copper rail, armature, and sabot materials, the technique of metal ion implantation using a vacuum arc ion source has been employed. Preliminary tests have been conducted to identify the best implant species to improve spark erosion resistance, scratch resistance and hardness. The implanted species included Al, Ti, Cr, Ni, Ta, Ag, and W. The implantation energy range and dose varied between 100–180 KeV and 0.4 to 2 × 1017 cm-2, respectively . Several analytical techniques were also used to assess the effect of implanted species. These included Rutherford Back Scattering (RBS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Microhardness Measurements, Spark Erosion and Scratch Testing. It has been tentatively concluded that Ta and Ni implantation of the copper rail substantially improve wear and inhibit arc erosion. There is also sufficient evidence to indicate that implantation of the aluminum armature with Cr and Ta, involving two stages of implantation, will also improve its mechanical and wear properties.

1995 ◽  
Vol 396 ◽  
Author(s):  
I.G. Brown ◽  
A. Anders ◽  
S. Anders ◽  
M.R. Dickinson ◽  
R.A. MacGill ◽  
...  

AbstractIon implantation by intense beams of metal ions can be accomplished using the dense metal plasma formed in a vacuum arc discharge embodied either in a vacuum arc ion source or in a ‘metal plasma immersion’ configuration. In the former case high energy metal ion beams are formed and implantation is done in a more-or-less conventional way, and in the latter case the substrate is immersed in the plasma and repetitively pulse-biased so as to accelerate the ions at the high voltage plasma sheath formed at the substrate. A number of advances have been made in the last few years, both in plasma technology and in the surface modification procedures, that enhance the effectiveness and versatility of the methods, including for example: controlled increase of the ion charge states produced; operation in a dual metal-gaseous ion species mode; very large area beam formation; macroparticle filtering; and the development of processing regimes for optimizing adhesion, morphology and structure. These complementary ion processing techniques provide the plasma tools for doing ion surface modification over a very wide parameter regime, from ‘pure’ ion implantation at energies approaching the MeV level, through ion mixing at energies in the ∼1 to ∼100 keV range, to IBAD-like processing at energies from a few tens of eV to a few keV. Here we review the methods, describe a number of recent developments, and outline some of the surface modification applications to which the methods have been put.


1995 ◽  
Vol 388 ◽  
Author(s):  
Xiang Lu ◽  
Nathan W. Cheung

AbstractSi1-x-yGexCy/Si heterostuctures were formed on Si (100) surface by Ge and C implantation with a high dose rate MEtal - Vapor Vacuum arc (MEVVA) ion source and subsequent Solid Phase Epitaxy (SPE). after thermal annealing in the temperature range from 600 °C to 1200 °C, the implanted layer was studied using Rutherford Back-scattering Spectrometry (RBS), cross-sectional High Resolution Transmission Electron Microscopy (HRTEM) and fourbounce X-ray Diffraction (XRD) measurement. Due to the small lattice constant and wide bandgap of SiC, the incorporation of C into Si-Ge can provide a complementary material to Si-Ge for bandgap engineering of Si-based heterojunction structure. Polycrystals are formed at temperature at and below 1000 °C thermal growth, while single crystal epitaxial layer is formed at 1100 °C and beyond. XRD measurements near Si (004) peak confirm the compensation of the Si1-x Gex lattice mismatch strain by substitutional C. C implantation is also found to suppress the End of Range (EOR) defect growth.


2010 ◽  
Vol 160-162 ◽  
pp. 1450-1457 ◽  
Author(s):  
Yong Zhao ◽  
Shuo Hou ◽  
Xiao Jun Liang ◽  
Li Guang Fang ◽  
Guang Hu Sheng ◽  
...  

Dry and wet oxidation silica films doped with silicon ions were prepared using metal vapor vacuum arc (MEVVA) ion source implanter. The does of Si ion beams were kept constant at 3×1016 /cm2 and the energy varied from 42KeV to 70KeV. Five photoluminescence (PL) bands at the wavelength of 560nm, 580nm, 620nm, 650nm and 730nm have been observed at room temperature in all samples. The results of XRD showed none of Si nanocrystals were formed in the as-implanted silica films and originations of the PL bands were defects introduced by implantation. The 560nm PL band originated from oxygen surplus defect small peroxy radical (SPR), whereas the PL bands which ranges from the wavelength of 620nm to 730nm were attributed to non bridge oxygen hole center (NBOHC). Elevating implantation energy resulted in intensity increasing of 560nm PL band of dry oxidation samples but had inverse effects on wet oxidation samples. Influence mechanism of implantation energy on the defect photoluminescence was discussed in this article.


2012 ◽  
Vol 83 (2) ◽  
pp. 02A501 ◽  
Author(s):  
A. G. Nikolaev ◽  
E. M. Oks ◽  
K. P. Savkin ◽  
G. Yu. Yushkov ◽  
I. G. Brown

Author(s):  
J Adamczewski ◽  
A Stephan ◽  
J Meijer ◽  
H.W Becker ◽  
H.H Bukow ◽  
...  

2011 ◽  
Vol 1354 ◽  
Author(s):  
Emel Sokullu-Urkac ◽  
Ahmet Oztarhan ◽  
Ismet Deliloglu-Gurhan ◽  
Sultan Gulce-Iz ◽  
Feyzan Ozdal-Kurt ◽  
...  

ABSTRACTWe have explored the application of ion implantation as a tool for the enhancement of neural cell growth on glass surfaces. Glass substrates were ion implanted with gold and with carbon using a metal vapor vacuum arc (MEVVA) ion source-based implantation system at Ege University Surface Modification Laboratory. The implantation dose was varied over the range 1014 – 1017 ions/cm2 and the ion energy spanned the range 20 – 80 keV. B35 neural cells were seeded and incubated on the implanted substrates for 48h at 37°C. After 2-days in culture the cell attachment behavior was characterized using phase contrast microscopy. The adhesion and direct contact of neural cells on these ion implanted glass surfaces were observed


2009 ◽  
Vol 75 ◽  
pp. 7-12
Author(s):  
P.W. Shum ◽  
Zhi Feng Zhou ◽  
K.Y. Li

Carbon ion implantation has often been considered as an additional method to further improve the wear, corrosion and oxidation resistance of hard coatings on tools or machine parts. The present research investigates the effect of carbon implantation on the structural and mechanical properties of the sputter-deposited solid solution Ti-Al-N coatings. The carbon implantation was carried out by using metal vapour vacuum arc ion source (MEVVA) with solid cathode at energies of 5 and 50 keV, and a dose of 6×1017 atoms cm-2. The mechanical and the microstructure properties of the implanted layer were identified by a variety of analytic techniques, such as nano-indentation, x-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD) etc. Additionally, the wear performance of the samples was evaluated by a typical ball-on-disk tribometer in dry conditions. The results showed that the coatings with high energy carbon implantation exhibited an enhanced hardness. The improved hardness could be attributed to the formation of TiC phase, as indicated in XPS. In the sliding tests, the coatings with the post-treatment of carbon implantation showed an improved tribological property in terms of friction coefficient and wear rate. The friction coefficient could be reduced from 0.6 to 0.1. The coatings had ten-fold better wear resistance than the coating without ion implantation.


1989 ◽  
Vol 147 ◽  
Author(s):  
I. G. Brown ◽  
M. D. Rubin ◽  
K. M. Yu ◽  
R. Mutikainen ◽  
N. W. Cheung

AbstractWe have used high-dose metal ion implantation to ‘fine tune’ the composition of Y-Ba- Cu-O thin films. The films were prepared by either of two rf sputtering systems. One system uses three modified Varian S-guns capable of sputtering various metal powder targets; the other uses reactive rf magnetron sputtering from a single mixed-oxide stoichiometric solid target. Film thickness was typically in the range 2000–5000 A. Substrates of magnesium oxide, zirconia-buffered silicon, and strontium titanate have been used. Ion implantation was carried out using a metal vapor vacuum arc (MEVVA) high current metal ion source. Beam energy was 100–200 keV, average beam current about 1 mA, and dose up to about 1017 ions/cm2. Samples were annealed at 800 – 900°C in wet oxygen. Film composition was determined using Rutherford Backscattering Spectrometry (RBS), and the resistivity versus temperature curves were obtained using a four-point probe method. We find that the zero-resistance temperature can be greatly increased after implantation and reannealing, and that the ion beam modification technique described here provides a powerful means for optimizing the thin film superconducting properties.


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