Thermal conductivity and bending strength of SiC composites reinforced by pitch-based carbon fibers
Thermal conductivity and bending strength of SiC composites reinforced by pitch-based carbon fibers
复制标题
DOI：
10.1007/s40145-021-0527-5
复制
发表时间：
2022-01
影响因子：
16.9
通讯作者：
L. Cao;Yongsheng Liu;Yunhai Zhang;Yejie Cao;Jingxin Li;Jie Chen;Lu Zhang;Zheng Qi
中科院分区：
文献类型：
--
作者：
L. Cao;Yongsheng Liu;Yunhai Zhang;Yejie Cao;Jingxin Li;Jie Chen;Lu Zhang;Zheng Qi
通过控制反应温度和树脂碳含量，采用反应熔融浸渗法（RMI）制备了沥青基碳纤维增强碳化硅（SiC）复合材料。采用多种分析方法对不同制备条件下得到的复合材料的导热系数和弯曲强度进行了表征。结果表明，在RMI过程中，SiC晶须（SiCw）的形成符合气-固（VS）机理。SiCw对Cpf/SiC复合材料的增韧起着重要的作用，主要是由于裂纹的桥接、裂纹的偏转和SiCw的拔出。随着反应温度的升高，复合材料的导热系数沿沿着面内和厚度方向先增大后减小。在反应温度为1600 °C时，沿着面内和厚度方向的热导率估计分别为203.00和39.59 W/（m·K）。在这些条件下，弯曲强度记录为186.15±3.95 MPa。RMI前树脂碳含量的增加导致了更多SiC基体的生成。沿着面内和厚度方向的热导率保持稳定，理想值分别为175.79和38.86 W/（m·K）。通过比较，最佳弯曲强度提高到244.62±3.07 MPa。总之，这些研究结果为沥青基碳纤维增强SiC陶瓷复合材料的应用前景看好。
In this work, pitch-based carbon fibers were utilized to reinforce silicon carbide (SiC) composites via reaction melting infiltration (RMI) method by controlling the reaction temperature and resin carbon content. Thermal conductivities and bending strengths of composites obtained under different preparation conditions were characterized by various analytical methods. Results showed the formation of SiC whiskers (SiCw) during RMI process according to vapor—solid (VS) mechanism. SiCwplayed an important role in toughening the Cpf/SiC composites due to crack bridging, crack deflection, and SiCwpull-out. Increase in reaction temperature during RMI process led to an initial increase in thermal conductivity along in-plane and thickness directions of composites, followed by a decline. At reaction temperature of 1600 °C, thermal conductivities along the in-plane and thickness directions were estimated to be 203.00 and 39.59 W/(m·K), respectively. Under these conditions, bending strength was recorded as 186.15±3.95 MPa. Increase in resin carbon content before RMI process led to the generation of more SiC matrix. Thermal conductivities along in-plane and thickness directions remained stable with desirable values of 175.79 and 38.86 W/(m·K), respectively. By comparison, optimal bending strength improved to 244.62±3.07 MPa. In sum, these findings look promising for future application of pitch-based carbon fibers for reinforcement of SiC ceramic composites.