Nv. Pleshivtsev et Ea. Krasikov, CORROSION PROTECTION OF METALS, ALLOYS AND STEELS BY ION-BOMBARDMENT (REVIEW), Russian metallurgy. Metally, (4), 1995, pp. 64-93
A systematic review is given of the results of numerous works devoted
to the problem of protection by ion bombardment of metals, alloys and
steels against corrosion in various media. The optimum conditions Lire
given for irradiating metallic materials. which provide a severalfold
increase in corrosion resistance (in some cases. by tens. hundreds or
even some thousand times). Unfortunately, in most works the authors r
estrict themselves to the potential-dynamical studies. Just in few wor
ks rests of protective properties provided by ion implantation were ma
de by the absolute gravimetric method for several hundred or thousand
hours, in particular, ,it elevated temperatures (550 - 850 degrees C).
Special attention in our review is given to the works performed ct in
Russia and in the countries of the former Soviet Union. We indicate t
he possibility of obtaining alloys With new, unusual composition of th
e surface layers. which cannot be fabricated by conventional technique
s. The possibility of amorphization of such surface layers is also poi
nted out. Experimental and theoretical investigations of the mechanism
of deep penetration of ions into metals and formation of high concent
rations as of radiation defects at depths of several hundred micromete
rs are also considered. The possibility of obtaining a nearly 100% con
centration of implanted atoms in the surface laver is demonstrated. We
consider processes and mechanisms induced by ion bombardment and resi
dual gases in the vacuum chamber, which raise the corrosion resistance
of metallic materials. The methodology is described of the thermodyna
mical analysis of complex heterogeneous systems of heat-resistant allo
ys with the aim of the proper choice of alloying ions, optimum energie
s, irradiation doses. current densities. and post-implantation heat-tr
eatment conditions. We present the major characteristics of (1) the st
ationary sources of pas ions providing currents up to 1 A: (2) the pul
sed sources with currents up to 60 A and pulse widths up to 1 s. and w
ith currents up to 300 A and pulse widths of 0.3 mu s: (3) the hydroge
n plasma fluxes with the energy density 100 J/cm(2) in a 30-mu s pulse
. at proton energy from 0.2 to 120 keV: (4) the beams and fluxes of pl
asma of metals and any materials conducting electric current, with ion
current up to 1 A in pulses of up to 400 mu s width and pulse recurre
nce frequency up to 100 Hz, with the mean ion energy between 100 and 3
00 keV.