Developing Oxidation-resistant ZrC-based Coating via Plasma Spraying for Advanced Thermal Protection Systems

Ultra-high temperature ceramic (UHTC) borides, such as ZrB₂ and HfB₂, have been widely investigated for thermal protection system (TPS) in extreme environments including hypersonic flight, nuclear reactor and advanced energy systems, due to their high thermal conductivity and melting point. However, they exhibit poor oxidation resistance and limited fracture toughness for extended applications beyond ~1600°C. Zirconium carbide (ZrC), with its ultra-high melting point (3540 °C) and excellent thermal shock resistance, has recently emerged as a promising material for such applications. By combining ZrC with transition metal carbides and silicon carbide (SiC), stable protective oxide layer can form even at temperatures exceeding 2000°C. This talk will present findings from exploration to develop oxidation resistant ZrC-based coating using plasma spraying process with a focus on high temperature stability. The influence of processing condition on oxide inclusions and coating structure will be elaborated and its impact on the performance assessed using isothermal oxidation and high temperature oxyfuel flame test will be discussed. The underlying mechanisms driving these results will be examined, offering valuable insights for further development of TPS for extreme environments.