Surface-alloy formation in film–substrate melting by intense pulsed electron beam. Part 1

Abstract

The elemental and phase composition and defect structure of the surface layer on 40X steel is compared for two cases: (1) treatment by intense pulsed electron beam; (2) alloying by melting of a film–substrate (copper–40X steel) system under irradiation by intense electron pulses. The evolution of the structure in the steel’s surface layer is studied as a function of the energy density of the pulsed electron beam. Highspeed solidification and subsequent quenching of 40X steel leads to the formation of a modified layer (thickness up to 30 µm). Cell structure is formed in the surface layer; the mean cell size is increased from 240 to 500 nm with increase in energy density of the pulsed electron beam from 10 to 20 J/cm2 (ten pulses). The treatment of a film–substrate (copper–40X steel) system by intense electron pulses is accompanied by the formation of surface alloy with quenched structure, hardened by copper nanoparticles.