Formation and corrosion resistance of amorphous Ti base alloys

Corrosion resistant amorphous Ti-B and Ti-Si alloys were prepared on various substrates by RF sputtering. The alloying of B content of 8 at% or more stabilizes the amorphous structure. The corrosion properties of Ti alloys were evaluated by measuring the polarization curves in 1N HCl. Although the addition of B to crystalline bulky Ti shifts the corrosion potentials of Ti to the less nobles of -0.5 V(SCE) or less, that of B to amorphous sputtered Ti moves the corrosion potentials to the noble side of +0.3 V(SCE). The current densities of amorphous Ti-B alloys at 0.1V(SCE) of the passive state are lower than that of the crystalline bulky alloys. Ti-Si sputtered alloys were amorphous at the silicon content of 12 at% or more. The amorphous Ti-Si alloys also show superior corrosion resistance, compared the crystalline Ti-Si alloys.