Design of the multiple transition metals interlayer process to diffusion bond ZrCx ceramics

- A Ti/Zr/Ti interlayer was designed to join ZrCx via forming homogeneous joint zone.
- The homogenization of ZrC joint was achieved at 1400 °C/1 h/20 MPa.
- Decreasing the thickness of Ti/Zr/Ti interlayer reduces the bonding temperature.
- The joint strength (162 MPa) and hardness (30.1 GPa) approach that of the ceramic.

In the study summarized in this paper, it is hypothesized that ZrCx with fewer carbon vacancies (e.g. stoichiometric ZrC) could form a homogenous joint when using a new multilayered design of the interlayer, consisting of a set of transition metals Ti/Zr/Ti. The proof of the hypothesis is obtained by performing diffusion bonding of ZrC with Ti/Zr/Ti interlayer under different temperature and time conditions, notably at 1400 °C/1 h/20 MPa. This design also applies to ZrCx with a larger population of carbon vacancies, like ZrC0.85. It is established that the mechanical integrity of the joint zone has been dramatically improved by the homogenization of the joint, which is comparable to that of the base ceramics. The homogeneous microstructure and outstanding mechanical properties demonstrate the great potential of this multiple interlayer design.

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