Surface Treatment of Materials with High Current Pulsed Electron Beam

Abstract

High current pulsed electron beam (HCPEB) is now becoming a promising energetic source for the surface treatment of materials. When the concentrated electron flux transferring its energy into a very thin surface layer within a short pulse time, superfast processes such as heating, melting, evaporation and consequent solidification, as well as dynamic stress field induced by an abrupt thermal distribution in the interactive zone impart surface layer with improved physicochemical and mechanical properties. The present paper reports mainly our experimental research work on this new-style technique. Investigations performed with a variety of constructional materials (aluminum, carbon and mold steel, magnesium alloys) have shown that the most pronounced changes of composition, microstructure and properties occur in the near-surface layers, while the thickness of the modified layer with improved mechanical properties (several hundreds of micrometers) is significantly greater than that of the heat-affected zone due to the propagation of stress wave. The surfaces treated with either simply several pulses of bombardment or complex techniques, such as rapid alloying by HCPEB can exhibit improved mechanical and physicochemical properties to some extent.