Microstructure and properties of Nb/Ta multilayer films irradiated by a high current pulse electron beam

Nb/Ta multilayer films deposited on Ti6A14V substrate with Nb and Ta monolayer thicknesses of 30 nm, 120 nm, and 240 nm were irradiated by a high current pulse electron beam （HCPEB） to prepare Nb-Ta alloyed layers. The mi- crostructure and the composition of the outmost surface of melted alloyed layers were investigated using a transmission electron microscope （TEM） equipped with an X-ray energy dispersive spectrometer （EDS） attachment. The Ta content of the alloyed surface layer prepared from the monolayer of thickness 30 nm, 120 nm, and 240 nm was- 27.7 at.%, 6.37 at.%, and 0 at.%, respectively. It was found that the Ta content in the alloyed layer plays a dominant role in the microstructure of the films. The hardness and the wear rate of the alloyed layers decrease with the increasing content of Ta in the surface laver.