Correlation between corrosion performance and surface wettability in ZrTiCuNiBe bulk metallic glasses

The corrosion properties of two Zr-based bulk metallic glass, Zr(41)Ti(14)Cu(12)Ni(10)Be(23) (LM1) and Zr(44)Ti(11)Cu(10)Ni(10)Be(25) (LM1b) were investigated by electrochemical measurements in simulated body fluid with pH value 7.4. With much lower current density and higher impedance values, as well as higher pitting potential, LM1b showed superior corrosion resistance to LM1. Under identical sample preparation and testing conditions, the difference in corrosion performance is found to relate closely to their surface wettability difference, as contact angle tests showed that LM1b is more hydrophobic than LM1. The excess free volume was measured and found having a close correlation with the wettability or the surface energy. (C) 2010 American Institute of Physics. [doi:10.1063/1.3429591]Physics, AppliedSCI(E)EI10ARTICLE25null9