%0 Journal Article
%T Surface Modification of Light Alloys by Low-Energy High-Current Pulsed Electron Beam
%A X. D. Zhang
%A S. Z. Hao
%A T. Grosdidier
%A J. X. Zou
%A B. Gao
%A B. Bolle
%A N. Allain-Bonasso
%A Y. Qin
%A X. N. Li
%A C. Dong
%J Journal of Metallurgy
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/762125
%X This paper reviews results obtained by the research groups developing the low-energy high-current pulsed electron beam (LEHCPEB) in Dalian (China) and Metz (France) on the surface treatment of light alloys. The pulsed electron irradiation induces an ultra-fast thermal cycle at the surface combined with the formation of thermal stress and shock waves. As illustrated for Mg alloys and Ti, this results in deep subsurface hardening (over several 100£¿¦Ìm) which improves the wear resistance. The analysis of the top surface melted surface of light alloys also often witnesses evaporation and condensation of chemical species. This phenomenon can significantly modify the melt chemistry and was also suggested to lead to the development of specific solidification textures in the rapidly solidified layer. The potential use of the LEHCPEB technique for producing thermomechanical treatments under the so-called heating mode and, thus, modify the surface crystallographic texture, and enhance solid-state diffusion is also demonstrated in the case of the FeAl intermetallic compound. 1. Introduction Light alloys, such as Mg-, Al-, and Ti-based alloys, have attracted increasing attention in the past few decades owing to their low density and, correspondingly, their high strength/ductility ratio. Because of this, light alloys are increasingly used to replace steels in industrial components. However, these light alloys are all facing some serious surface-related disadvantages such as poor wear or corrosion resistance that have strongly limited their potential for some specific industrial applications. Therefore, surface treatment techniques should be applied on these light alloys in order to improve their global performance. The low-energy high-current pulsed electron beam (LEHCPEB) process is a fairly new surface modification technique [1, 2]. The LEHCPEB sources have been first developed for surface treatment of materials by Proskurovsky and Ozur in Tomsk (Russia) [1¨C3]. As one kind of high-power charged particle beam, LEHCPEB exhibits essential advantages over pulsed laser and ion beams by its high efficiency, simplicity, and reliability. The pulsed electron irradiation induces (i) a rapid heating and cooling of the surface together with (ii) the formation of thermal stress and stress waves [4, 5]. As a result, improved surface properties of the material, often unattainable with conventional surface treatment techniques, can be obtained fairly easily. This is particularly true for tribological [2, 4, 6, 7] and corrosion properties [7¨C10]. Proskurovsky et al. [1¨C4] have
%U http://www.hindawi.com/journals/jm/2012/762125/