Fabrication and oxidation behavior of LaB6-ZrB2 composites

LaB6-ZrB2 eutectic composites were sintered by hot pressing. The oxidation behavior of LaB6-ZrB2 eutectic composites was studied in the temperature range of 600-1300 °C. It was shown that the sample weight increased with increasing oxidation temperature and prolonging holding time. The rate of weight change was described by kp=6.24×10−4exp(−38,940/RT) g2/m2 s, but it changed according to the change of oxidation time at 1200 °C. Weight gain was evident in less than 1 h, but it slowed down subsequently due to the evaporation of B2O3. The rate of weight change increased abruptly at 1300 °C. The oxidation resistance of LaB6-ZrB2 composites was higher than that of monolithic LaB6.