Air-oxidation behavior of a [(Fe50Co50)75B20Si5]96Nb4 bulk metallic glass at 500–650 °C

Abstract The oxidation behavior of a [(Fe 50 Co 50 ) 75 B 20 Si 5 ] 96 Nb 4 bulk metallic glass was studied over the temperature range of 500–650 °C in dry air. The oxidation kinetics generally followed the parabolic-rate law, and the parabolic-rate constants ( k p values) of the glassy alloy increased with increasing temperature. The k p values of the glassy alloy were lower than those of the binary FeCo alloy. The scales formed on the FeCo alloy consisted of Fe 3 O 4 and minor Fe 2 O 3 , while B 2 O 3 was also observed on the amorphous substrate, whose formation may be responsible for the slower oxidation rates of the glassy alloy.