In situ synthesis mechanism of ZrC-ZrB2/Cu composites prepared by SHS-casting method

The self-propogating high-temperature syntheis (SHS) experiments in the glove box indicated that the combustion temperature decreased and the ignition time increased with increasing B4C size in Cu-Zr-B4C system. Once B4C size exceeded 28 mu m, the full conversion of ZrC and ZrB2 failed. In situ ZrC and ZrB2 ceramic particle-reinforced Cu matrix composites were produced by the self-propagating high-temperature synthesis reaction of Cu-Zr-B4C system in molten Cu. Moreover, the phase formation mechanism was investigated by the combustion wave quenching experiment of Cu-Zr-B4C powder compact in Cu liquid. Results showed that ZrC and ZrB2 were mainly formed by the dissolution-reaction-precipitation mechanism. A developed method arresting the combustion front of a reactant in molten metal was proposed.