Electron-beam surface alloying of Ti substrates with Ta films

Abstract

We report electron-beam surface alloying of Ti substrates with Ta. The Ti substrates were covered by a Ta coating with a thickness of 2 μm. The samples were alloyed by a scanning electron beam, with the beam deflection geometry in the shape of the infinity symbol (∞). Two experiments were implemented, where the width of the infinity symbol was kept constant at 8 mm, while the height was 8 mm for the first experiment and 4 mm for the second one. The phase composition of the specimens produced was studied by X-ray diffraction (XRD). The microstructure and chemical composition were investigated by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), respectively. The results showed that the phase composition consisted of a double phase structure of α’ martensitic and of beta phases. Some amount of pure Ta remained in the alloyed layer produced by the first experiment. Also, the distribution of the alloying element into the substrate was significantly more homogeneous in the case of the second one.