Reaction behavior and formation mechanism of ZrC and ZrB_2 in the Cu-Zr-B_4C system

摘要

In this work, the formation mechanism of ZrC and ZrB_2 in the Cu-Zr-B_4C system was studied by differential scanning calorimeter and X-ray diffraction. Moreover, the effect of heating rate on the reaction behavior was also investigated. The results revealed that the heating rate did hardly influence the reaction process and product in the range of 10-30 °C/min. The formation mechanism of ZrC and ZrB_2 in the Cu-Zr-B_4C system could be ascribed to the solid-state reaction between Zr and B_4C particles, and the replacement reactions of B_4C with the Cu-Zr liquid and copper zirconium compounds. The addition of Cu in the Cu-Zr-B_4C reactants can change the phase evolution route via producing various Cu-Zr intermediate phases and promote the formation of ZrC and ZrB_2.