CORROSION PROTECTION OF METALS, ALLOYS AND STEELS BY ION-BOMBARDMENT (REVIEW)

Citation
Nv. Pleshivtsev et Ea. Krasikov, CORROSION PROTECTION OF METALS, ALLOYS AND STEELS BY ION-BOMBARDMENT (REVIEW), Russian metallurgy. Metally, (4), 1995, pp. 64-93
Citations number
132
Categorie Soggetti
Metallurgy & Metallurigical Engineering
Journal title
ISSN journal
00360295
Issue
4
Year of publication
1995
Pages
64 - 93
Database
ISI
SICI code
0036-0295(1995):4<64:CPOMAA>2.0.ZU;2-J
Abstract
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.