Effect of group 5 elements on the formation and corrosion behavior of Ti-based BMG matrix composites reinforced by icosahedral quasicrystalline phase

Abstract

The addition of a low concentration of group 5 elements to the Ti40Zr29Be16Cu8Ni7 BMG alloys resulted in the formation of particles with icosahedral quasiciystalline symmetry of different size and volume fraction embedded in BMG matrices. Since the i-phase is known for its excellent corrosion resistance, the properties of the TM-containing Ti-based BMGs, with 0 <= TM <= 5 at.%, have been investigated in aerated 1 M H2SO4 + 2 ppm F- solution with 80 degrees C by means of potentio-dynamic, potentio-static and chemical immersion. The addition of 3 at.% Ta provided an alloys with properties similar to those of Ti-6Al-4V alloy in a solution simulating the environment of a bipolar plate in polymer electrolyte membrane. The high corrosion resistances of the in situ BMG matrix composites are attributed to the similarity in the composition of the i-phase and amorphous matrices as well as the formation of protective oxide layers rich in Ti, Zr and V/Ta/Nb. (C) 2014 Elsevier B.V. All rights reserved.