Jin Hua, Meng Songhe, Xie Weihua, Xu Chenghai, Niu Jiahong
National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin 150001, China.
Materials (Basel). 2016 Nov 29;9(12):967. doi: 10.3390/ma9120967.
ZrB₂-based nanocomposites with and without carbon nanotubes (CNTs) as reinforcement were prepared at 1600 °C by spark plasma sintering. The effects of CNTs on the microstructure and mechanical properties of nano-ZrB₂ matrix composites were studied. The results indicated that adding CNTs can inhibit the abnormal grain growth of ZrB₂ grains and improve the fracture toughness of the composites. The toughness mechanisms were crack deflection, crack bridging, debonding, and pull-out of CNTs. The experimental results of the nanograined ZrB₂-CNTs composites were compared with those of the micro-grained ZrB₂-CNTs composites. Due to the small size and surface effects, the nanograined ZrB₂-CNTs composites exhibited stronger mechanical properties: the hardness, flexural strength and fracture toughness were 18.7 ± 0.2 GPa, 1016 ± 75 MPa, and 8.5 ± 0.4 MPa·m, respectively.
以1600℃通过放电等离子烧结制备了含和不含碳纳米管（CNT）作为增强体的ZrB₂基纳米复合材料。研究了碳纳米管对纳米ZrB₂基复合材料微观结构和力学性能的影响。结果表明，添加碳纳米管可抑制ZrB₂晶粒的异常长大，并提高复合材料的断裂韧性。韧性机制包括裂纹偏转、裂纹桥接、脱粘以及碳纳米管的拔出。将纳米晶ZrB₂-CNTs复合材料的实验结果与微晶ZrB₂-CNTs复合材料的实验结果进行了比较。由于尺寸小和表面效应，纳米晶ZrB₂-CNTs复合材料表现出更强的力学性能：硬度、抗弯强度和断裂韧性分别为18.7±0.2GPa、1016±75MPa和8.5±0.4MPa·m。
