Effect of zirconium addition on the phase transformations in as-cast and heat-treated Ti–Zr–Si–B alloys

Abstract

This work reports on effect of zirconium addition on the phase transformations in as-cast and heat-treated Ti–6.7Zr–22.2Si–11.1B, Ti–7Zr–15Si–7.5B, Ti–7Zr–10Si–5B, Ti–7Zr–7.5Si–15B and Ti–7Zr–30Si–5B alloys (at.%). After arc melting, these Ti–Zr–Si–B alloys were heat-treated at 1200°C for 90h. Samples of as-cast and heat-treated Ti–Zr–Si–B alloys were evaluated by X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry, and wavelength X-ray dispersive spectrometry. Nanosized eutectic structure constituents were observed in microstructures of as-cast Ti–Zr–Si–B alloys. TiSS (ss-solid solution), Ti6Si2B, TiB and Ti5Si3 dissolved up to 5.3, 14.2, 1.5 and 11.6at.% Zr, respectively, which is in agreement with the shift of their peaks toward smaller diffraction angles.