Cyclic Oxidation Behavior of c-BN and h-BN at Elevated Temperatures

The aim of this study is to determine the cyclic oxidation behavior of cubic boron nitride (c-BN) and hexagonal boron nitride (h-BN) in air atmosphere at elevated temperatures. For this purpose, as-received powders of both compounds were first characterized by XRD and SEM. c-BN and h-BN powders were shaped by cold pressing for oxidation studies. Tests were performed in air atmosphere at 800 degrees C and 1000 degrees C for 5, 10, 15 and 20 hours. After each oxidation test, the mass changes were measured. XRD, SEM and EDS analyses were conducted on the oxidized samples and the results were discussed.