Hot oscillatory pressing of B4C ceramics for improving densification and mechanical properties

B4C ceramics were prepared by conventional hot pressing (HP) and hot oscillatory pressing (HOP). The results show that at the temperature and pressure studied here, the main densification mechanism of HP is grain‐boundary sliding, whereas that of HOP is plastic deformation caused by dislocation gliding, indicating that the oscillatory pressure promoted plastic deformation of the material. The hardness of B4C prepared by HOP reaches 39.5 GPa, which is much higher than the hardness of sample prepared by HP. The current study suggests that HOP is promising for preparing high‐performance B4C ceramics.