Fabrication of ZrC particles and its formation mechanism by self-propagating high-temperature synthesis from Fe–Zr–C elemental powders

ZrC particles were prepared via self-propagating high-temperature synthesis (SHS) reaction from 0 to 30 wt.% Fe–Zr–C elemental powder mixtures. The ZrC particles of the SHS products greatly decreased from about 10 μm with an irregular shape in free Fe addition to nano-meter order with a nearly spherical shape in 30 wt.% Fe addition. The reaction mechanism of ZrC during the SHS processing was explored through the microstructural observation and phase constituents analysis on the combustion-wave quenched sample in combination with differential thermal analysis (DTA). For the low Fe contents, the solid-state reaction between C and Zr powders should be responsible for the formation of ZrC. While for the high Fe contents, the formation mechanism of ZrC could be ascribed to the dissolution of C into the Fe–Zr melt and the precipitation of ZrC. The addition of Fe to Zr–C reactants not only inhibits the growth of ZrC particles but also promotes the occurrence of ZrC-forming reaction.

► ZrC particles were synthesized through SHS route from the Fe–Zr–C powder mixtures.
► With increasing Fe contents, the sizes of ZrC particles are about 100 nm.
► For the low Fe contents, the formation of ZrC was controlled by solid-state reaction.
► For the high Fe contents, ZrC was formed by the solution–precipitation mechanism.
► The addition of Fe to Zr–C reactants promotes the occurrence of ZrC reaction.