Study of the influence of vanadium and niobium on the structure of Ti-Al-V and Ti-Al-Nb alloys formed by selective electron beam alloying

Three-component surface alloys of the Ti-Al-Nb and Ti-Al-V systems were formed by means of selective electron beam alloying; the procedure involved DC magnetron sputtering deposition of multilayer Al and Nb or Al and V films with a thickness of 1 mu m of each layer on a commercially-pure Ti substrate. The samples prepared were then electron-beam surface-alloyed under identical technological conditions. The specimens were examined by scanning electron microscopy (SEM); their chemical composition was studied by energy dispersive Xray spectroscopy (EDX). X-ray diffraction (XRD) was used to determine the crystallographic structure. Intermetallic alloys in the system of Ti-Al-V were successfully produced with an electron beam current of 15 mA. As the current was increased from 15 mA to 20 mA, only pure titanium was visible, probably due to the evaporation of the alloying materials. In the Ti-Al-N system, intermetallic alloys were formed when the electron beam current reached 25 mA.