Low temperature oxidation behavior of Mo2BC coatings

Abstract

Mo2BC exhibits a unique combination of high stiffness and moderate ductility, enabling the application as a protective and wear resistant coating. As the low temperature oxidation behavior of Mo2BC coatings is unexplored, direct current magnetron sputtered Mo2BC coatings were oxidized at temperatures ranging from 500 to 100 °C for up to 28 days. Time-of-flight elastic recoil detection analysis reveals that the onset of oxidation takes place at approximately 300 °C as a significant increase in the O content was observed. Crystalline oxide scales containing orthorhombic MoO3 were identified after oxidation for 15 min at 500 °C and 10 days at 200 °C. Isothermal oxidation at 200 and 100 °C exhibits oxide scale thicknesses of 401 ± 33 and 22 ± 10 nm after 14 days. Oxidation for 28 days at 100 °C exhibits an oxide scale thickness of 13 ± 3 nm, which is comparable to the aforementioned oxide scale thickness after oxidation for 14 days at 100 °C. Based on the combination of mechanical properties and the here reported low temperature oxidation behavior, Mo2BC coatings qualify for applications in solid wood machining and low temperature forming processes at temperatures close to 100 °C or below.Mo2BC exhibits a unique combination of high stiffness and moderate ductility, enabling the application as a protective and wear resistant coating. As the low temperature oxidation behavior of Mo2BC coatings is unexplored, direct current magnetron sputtered Mo2BC coatings were oxidized at temperatures ranging from 500 to 100 °C for up to 28 days. Time-of-flight elastic recoil detection analysis reveals that the onset of oxidation takes place at approximately 300 °C as a significant increase in the O content was observed. Crystalline oxide scales containing orthorhombic MoO3 were identified after oxidation for 15 min at 500 °C and 10 days at 200 °C. Isothermal oxidation at 200 and 100 °C exhibits oxide scale thicknesses of 401 ± 33 and 22 ± 10 nm after 14 days. Oxidation for 28 days at 100 °C exhibits an oxide scale thickness of 13 ± 3 nm, which is comparable to the aforementioned oxide scale thickness after oxidation for 14 days at 100 °C. Based on the combination of mechanical properties and the here repo...