@article{Wang2026, 
author = {Zhuo Wang and Jiaojiao Gao and Jinpeng Song and Kuang Sun and Xiong Niu and Wei Xu and Ming Lv and Yanchun Zhou},
title = {Ultrasonic-assisted hot pressing (UAHP): A novel strategy to enhance densification and improve the mechanical properties of B4C},
year = {2026},
journal = {Journal of Advanced Ceramics},
volume = {15},
number = {2},
pages = {9221236},
keywords = {mechanical properties, toughening mechanism, ultrasonic assisted sintering, rapid densification, hot pressing (HP), boron carbide (B4C) ceramics},
url = {https://www.sciopen.com/article/10.26599/JAC.2025.9221236},
doi = {10.26599/JAC.2025.9221236},
abstract = {Ultrasonic-assisted hot pressing (UAHP) has shown significant potential in enhancing both the densification and mechanical performance of metallic materials. However, the poor high-temperature stability of ultrasonic systems severely limits its application in the fabrication of high-melting-point materials. To fill this gap, UAHP was operated at temperatures exceeding 2000 °C and employed in the preparation of monolithic boron carbide (B4C) ceramics for the first time. The densification behavior, microstructure evolution, and mechanical properties of B4C fabricated via UAHP were systematically investigated and compared with those prepared by conventional hot pressing (HP). It was demonstrated that the introduction of high-frequency ultrasonic vibration in UAHP can not only accelerate the densification rate but also reduce the densification temperature and enhance the mechanical properties of B4C. Specifically, the relative density of B4C increased from 90.90% to 97.22% at 1900 °C under UAHP, which was comparable to that achieved by HP at 1950 °C, indicating a 50 °C reduction in densification temperature. In addition, a significant increase in densification efficiency by reducing the densification time during UAHP endowed B4C with both near-full density and superior mechanical properties. The B4C ceramics prepared by UAHP at 1950 °C for 20 min and at 2050 °C for 5 min exhibited flexural strengths of 669.3±19.4 and 688.3±32.5 MPa, respectively, and fracture toughnesses of 4.37±0.23 and 4.22±0.29 MPa·m1/2, respectively. These results suggest that UAHP is a promising strategy for efficient densification and optimization of the mechanical properties of B4C ceramic and opens a new avenue for the preparation of difficult sintering ceramics.}
}