The effect of B₄C particle size on the reaction process and product in the Cu–Zr–B₄C system

ZrC and ZrB2 were prepared by self-propagating high-temperature synthesis in a Cu–Zr–B4C system. We explored the influence of B4C particle size on the reaction process, phase composition and microstructure of the products. The results show that the production of ZrC and ZrB2 is mainly controlled by the dissolution of B4C in Cu–Zr liquid. Increasing the size of B4C will not affect the reaction path, but will retard the formation of the Cu–Zr–B–C liquid. This leads to the incomplete conversion of ZrC and ZrB2 once the B4C exceeds 28 μm. In addition, ZrC and ZrB2 particle sizes greatly decrease from the micrometer dimension with a polyhedral morphology to the nanometer scale with a nearly spherical shape.