Abstract:The oxidation behavior of a Ti50Cu28Ni15Sn7 bulk metallic glass (TC4-BMG) was studied over the temperature range of 400–500 °C in dry air. The oxidation kinetics generally followed the parabolic-rate law, and the oxidation rates increased with increasing temperature. The scales formed on the TC4-BMG consisted mostly of TiO2 (rutile structure) intermixed with small amounts of CuO particles. It was found that the scaling rate of the amorphous alloy was slightly faster than that of the crystalline counterpart. The amorphous substrate transferred into the three crystalline phases of Ti3Sn, Ti3Cu4, and Ti(Ni,Cu) during the oxidation at 400–500 °C, indicating the occurrence of phase transformation.