Effect of alloying elements on the microstructure and corrosion behavior of TiZr-based bulk metallic glasses

[Display omitted] •Substituting few percents of Cu in TiZrCuPd BMG improves its passive behavior.•Sn and Si elements play a beneficial role on the metallurgical quality of BMG.•Heterogeneity within solid solution and casting defects act as weakening sites.•Adding Sn and Si elements limit the susceptibility to pitting corrosion. In this work, the effect of substituting Cu with small amounts of Sn and Si on the passive behavior and pitting resistance of the bulk metallic glass Ti40Zr10Cu36Pd14 was investigated. The Sn/Si substitution promoted homogenization of the solid solution and limited the presence of casting defects. In addition, unlike the heterogeneous passive film grown on TiZrCuPd, the passive films of the micro-alloyed materials were homogeneous, implying less sensitivity to film weakening and breakdown. Thus, alloying with small amounts of Sn and Si appears to be a viable approach to drastically improve the corrosion resistance of TiZrCuPd.