scholarly journals Application of Nuclear Techniques to the Investigation of the Oxidation Behavior of Ion-Implanted Steels

2019 ◽  
Vol 7 ◽  
pp. 222
Author(s):  
F. Noli ◽  
P. Misaelides

The oxidation behavior of ion-implanted steel samples in air, using Nuclear Reaction Analysis (NRA) and Rutherford Backscattering Spectroscopy (RBS) techniques. Austenitic stainless steel AISI 321 (Fe/Crl8/Ni8/Mn2/Ti) samples implanted with magnesium-, aluminum- and zirconium-ions (implantation energy 40 keV, dose: 1-1017 to 2-1017 ions/cm2) were oxidized in air in the temperature region 450-650 °C for several periods of time. The above implants were selected on the basis of the affinity to oxygen, as well as their ability to form protective oxides as MgO, AI2O3, Zr02 in order to improve the oxidation resistance of steel. The determination of the oxygen concentration and depth-profiles was performed by means of the 160(d, p)170 nuclear reaction. Rutherford Backscattering Spectroscopy was applied to investigate the near-surface layers and to determine the depth profiles of the implanted ions. The determination of the aluminum concentration and the depth distribution of the Al-ions was performed using the resonance at 992 keV of the 27Al(p, 7)28Si nuclear reaction whereas the concentration and the depth distribution of the Mg-ions by the means of the 24Mg(o;, p)27Al reaction. The excitation function of the 24Mg(a:, p)27Al nuclear reaction was studied in the energy region 4600-5000 keV and absolute cross section data allowing the determination of the Mg-profile were determined for this purpose.

Author(s):  
A. T. Fisher ◽  
P. Angelini

Analytical electron microscopy (AEM) of the near surface microstructure of ion implanted ceramics can provide much information about these materials. Backthinning of specimens results in relatively large thin areas for analysis of precipitates, voids, dislocations, depth profiles of implanted species and other features. One of the most critical stages in the backthinning process is the ion milling procedure. Material sputtered during ion milling can redeposit on the back surface thereby contaminating the specimen with impurities such as Fe, Cr, Ni, Mo, Si, etc. These impurities may originate from the specimen, specimen platform and clamping plates, vacuum system, and other components. The contamination may take the form of discrete particles or continuous films [Fig. 1] and compromises many of the compositional and microstructural analyses. A method is being developed to protect the implanted surface by coating it with NaCl prior to backthinning. Impurities which deposit on the continuous NaCl film during ion milling are removed by immersing the specimen in water and floating the contaminants from the specimen as the salt dissolves.


2019 ◽  
Vol 14 ◽  
pp. 95
Author(s):  
M. Kokkoris ◽  
P. Misaelides ◽  
S. Kossionides ◽  
Ch. Zarkadas ◽  
A. Lagoyannis ◽  
...  

The differential cross sections of the 12C(d,po)13C reaction applied to the determination of the depth distribution of carbon in near-surface layers of materials were determined in the projectile energy region F,dtiab — 900-2000 keV (in steps of 25 keV) and for detector angles between 135 ° and 170 ° (in steps of 5 ° ) using as targets 99.9% purity self-supported natural carbon (98.9% 12C - 1.1% 13C) foils of nominal thickness ca. lxlO18 at/cm2. The overall error in the absolute differential cross section measurements varied between ~6-22%. The results were compared with already published data and the explanation of the occurring differences was attempted.


2005 ◽  
Vol 98 (3) ◽  
pp. 033517 ◽  
Author(s):  
R. Klockenkämper ◽  
M. Becker ◽  
A. von Bohlen ◽  
H. W. Becker ◽  
H. Krzyzanowska ◽  
...  

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