Study on the synthesis and growth mechanisms of the refractory ZrC whiskers

ZrC whiskers, which can be used as a potential reinforcing and strengthening phase for ceramic composites, were successfully fabricated in an economical and efficient way by the carbothermal reduction technology. ZrC whiskers were synthesized from the mixture of ZrO2, C, Ni and NaF at 1500 °C in an argon atmosphere. The length, diameter and aspect ratio ranged from 60 to 100 μm, 1 to 3 μm and 20 to 50, respectively. Whiskers exhibited two major morphologies which were prismatic-like and cylindrical-like shapes. Combined with thermodynamic calculation and the morphology, the solid–liquid–solid (S–L–S) mechanism and the Ostwald ripening were considered to govern the whisker growth.