Stiffness and ductility can be achieved by reducing the grain size of ceramics to the nanometer scale. However, the deformation mechanism of nanoceramics is still controversial due to technical limitations. In this paper, via synchrotron radial x-ray diffraction technology combined with a diamond anvil cell, the deformation behavior of nanosized titanium nitride (TiN) has been studied in situ under high-pressure conditions up to 41.3 GPa. Results show that the nano-TiN exhibits a much higher bulk modulus and yield strength than its bulk counterpart. Nano-TiN starts to yield at around 17.3 GPa and the maximum yield strength is approximately 8.7 GPa at 41.3 GPa. The presence of 110 and 001 texture in nanosized TiN was confirmed under pressure, indicating a strong activity of dislocation. This paper suggests that the reduction in grain size to the nanoscale improves both the stiffness and ductility of TiN via a dislocation-mediated mechanism.

• Received 2 January 2024
• Accepted 6 March 2024

DOI:https://doi.org/10.1103/PhysRevMaterials.8.036001