Improvement of the Spark-Plasma-Sintering Kinetics of ZrC by High-Energy Ball-Milling

The effect of the duration of high‐energy ball‐milling on the spark‐plasma sintering (SPS) kinetics of additive‐free ZrC ultra‐high‐temperature ceramics (UHTCs) was investigated. It was found that the crystallite size of ZrC is refined progressively from the as‐purchased condition down to a few nanometers with increasing high‐energy ball‐milling time, and that this crystallite size refinement progressively enhances the SPS kinetics, reducing the characteristic temperatures of the sintering process. While this enhancement was found to be only moderate with the refinement to the ultra‐fine range, it was highly marked with the refinement to the nanometer range. Implications for the lower‐temperature processing of ZrC UHTCs are discussed.