Diffusion and solid solution formation between the binary carbides of TaC, HfC and ZrC

• Solubility rate of TaC–HfC, TaC–ZrC and HfC–ZrC systems was investigated.
• Solubility rate of TaC, HfC and ZrC was found to be in the order of ZrC > HfC > TaC.
• The Boltzmann–Matano Method was utilized to determine the coefficient of diffusion.

In this work, phase evolution, solid solution formation and diffusion behavior of three binary systems, including TaC–HfC, TaC–ZrC and HfC–ZrC, were investigated. In this regard, pure carbide powders of TaC, HfC, and ZrC were selected as starting raw materials. The prepared samples were heat treated at 2000 °C for 1 hour in Ar atmosphere. For each system, three compositions were chosen for phase evolution investigation by X-ray diffractometer. Moreover, three couple samples were prepared for diffusion behavior survey through SEM/EDX analyses. It was found that ZrC diffuses faster in TaC structure rather than HfC and a single phase solid solution phase with hosting TaC is formed in TaC–HfC and TaC–ZrC systems.