Author: Hao Chen, Yueming Li, Yawen Guo, Depeng Ji,Li Tian, Yiwang Bao, Wenfei Li, Yunhui Li,Qingming Xu, Jianwei Zhu, Guorui Zhao

Journal:Journal of the European Ceramic Society

DOI:https://doi.org/10.1016/j.jeurceramsoc.2024.01.050

Abstract / 摘要

The first high damage resistant ultra-high temperature ceramic ScB2C2 with
excellent hydrolysis resistance was successfully prepared through boron carbon thermal
reduction and hot pressing sintering using Sc2O3, B4C and graphite as raw materials.
The Vickers hardness, flexural strength, fracture toughness, Young’s modulus, shear
modulus, bulk modulus and Poisson’s ratio of as-prepared ScB2C2 ceramic are 6.0 ±
0.2 GPa, 246 ± 17 MPa, 4.11 ± 0.18 MPa·m1/2, 240 GPa, 101 GPa, 127 GPa and 0.18,
respectively. In the a-b plane (B2C2 sheet) and along the c-axis direction, ScB2C2
exhibits extremely strong anisotropy of chemical bonds and elastic properties. The high
residual strength, damage tolerance factor Dt and fracture toughness to strength ratio
KIc/σf indicates that ScB2C2 has excellent damage tolerance. In addition, ScB2C2
displayed remarkable thermal shock resistance and hydrolysis resistance. These unique
features endow ScB2C2 with significant potential for future ultra-high temperature
applications

Keyword / 关键词

ScB2C2, Crystal structure, Mechanical properties, Damage tolerance, Hydrolysis

resistance