Achieving superior strength-toughness synergy in ZrC-based ceramics: An in situ multiscale construction strategy via a two-step reactive SPS process

Abstract To overcome the poor sinterability and low fracture toughness (KIC) of zirconium carbide (ZrC) ceramics, a novel multiscale microstructure design was proposed via a two-step in situ reactive spark plasma sintering (SPS) process using ZrC, TiSi2, and B4C powders. During sintering, TiSi2 preferentially reacted with B4C to form TiB2 and primary silicon carbide (SiC), while the released Si further reacted with ZrC to yield ZrSi2 and secondary SiC. The two-step SPS (1600 °C/3 min + 1800 °C/10 min) promoted complete in situ reactions, liquid-phase sintering, and interdiffusion of Zr/Ti, leading to the formation of (Zr,Ti)C and (Ti,Zr)B2 solid solutions. With the addition of 30 mol% TiSi2 and 15 mol% B4C,…

• NN
  National Natural Science Foundation of China

  Awards: 52002098, 52002003
• HE
  Harbin Engineering University