The impact of high current pulses electron beam on the microstructure and surface properties of Sn/Al system

Abstract The purpose of this paper was to investigate surface alloying of Sn/Al system by high current pulses electron beam (HCPEB) irradiation. As a result, Sn covered on the surface and the formation of large size craters caused the increasing of surface roughness at the early stage of repeated pulsed irradiation. Subsequently, increasing pulsed irradiation led to the dissolution of Al and Sn together with elimination of craters forming a smooth allying layer with low surface roughness. On the topmost layer of alloying layer in Sn/Al system was the remelted layer with uniformly distributed ultrafine Sn particles. The beneath was diffused layer consisting of abundant structure defects, in the vicinity of which were separated out a large number of Sn particles. The microhardness was increased to about 0.82 GPa in the alloying layer after 35-pulsed samples. The tribological property was enhanced by HCPEB irradiation that induced the refinement of Sn particles and the formation of hard matrix.