Kinetic role of C/Zr ratio in the reaction process, combustion behavior, and synthetic product of 70 wt.% (xC–Zr)–30 wt.% Cu

The kinetic role of C/Zr ratio in the reaction processes, combustion behaviors, and synthesized products of 70 wt.% (xC–Zr)–30 wt.% Cu was investigated. Results indicated that ZrC particles were produced by the replacement reaction between carbon atoms and Zr–Cu melt. With an increase in C/Zr ratio, more carbon atoms combined with the zirconium atoms in Zr–Cu liquid. As a result, the formation rate of massive ZrC enhanced, which shortened the ignition time of combustion reaction. On the other hand, the quantity, the lattice parameter, and the x value of synthetic ZrCx increased, while the byproduct CuyZrx compounds decreased. These effects contributed to an increase in the burning temperature and ZrCx particle size. Moreover, it is also revealed that the formation of ZrCx is a multistep process, which leads to an inhomogeneous distribution of the particle size. Results from this work offer a theoretical reference for the kinetic research of combustion synthesis and related techniques, and provide a valuable guide to the in situ synthesis of composite materials containing ZrC.