Surface alloying by pulsed
intense electron beams.
G. Mueller1*, V. Engelko
2, A. Weisenburger 1, A. Heinzel 1
1- Forschungszentrum Karlsruhe, IHM, Postfach 3640, D-76021 Karlsruhe,
Germany
2- Efremov Institute of Electrophysical Apparatus,
196641, St. Petersburg, Russia
*Corresponding author. Tel +49-7247-82-4669;
fax:+49-7247-82-2256 E-mail: georg.mueller@ihm.fzk.de
Pulsed intense
electron beams are applied for modifications of material surface properties,
namely, for a change of microstructure and phase composition, for phase mixing
and the creation of metastable states. The modifications originate not only
from super fast solidification of the material surface, but also from the
creation of alloys in the modified surface layer. The procedure of surface
alloying is the following: on the surface of a base material a layer of another
material or material composite is deposited by a certain way (for example,
using a thin foil, galvanic or vapour deposition). The thickness of the layer
must be less than the penetration depth of electrons in this layer. Treating
the surface by electron beam leads to mixing of the deposited layer and the
base material.
In this report
results of numerical calculations and experimental studies of the thickness of
modified layers, distribution of implanted materials, microstructure and phase
composition inside the layers are presented. Possible physical mechanisms of
the alloying are discussed. In a second part the improvement of surface
properties, especially corrosion resistance against liquid lead, are presented.
It is shown that corrosion of OPTIFER IVc steel by liquid lead containing 8×10-6
at% oxygen is avoided by alloying of Al into the surface