Core–Shell Structure and Enhanced Mechanical Properties of TiB 2 ‐Based Ceramics With W Additive
Run‐Ping Liu, Bei‐Chen Gao, Kai Luo, Xin‐Zhuang Yang, Yang You, Wei‐Ming Guo, Hua‐Tay LinABSTRACT
TiB 2 ‐based ceramics containing 5 wt% metallic W were fabricated by spark plasma sintering, achieving a relative density of 99.79% ± 0.10%. TiB 2 ‐based ceramics containing 5 wt% Ni and Nd were also prepared as reference samples. The microstructure of TiB 2 ‐based ceramics with W additive exhibited a core–shell morphology, in which the core was a TiB 2 grain, and the shell is a (Ti, W) B 2 solid solution. The shell phase provided an effective grain‐boundary pinning effect, resulting in a refined average grain size of 1.37 ± 0.45 µm. The W‐added sample showed a Vickers hardness of 28.50 ± 0.62 GPa, higher than those of the 5 wt% Ni‐added (21.24 ± 2.86 GPa) and 5 wt% Nb‐added (25.26 ± 0.73 GPa) ceramics processed under similar conditions. The enhanced hardness is associated with near‐full densification, grain refinement, and solid‐solution‐induced lattice distortion.