中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 25 No. 5 May 2015 |
（1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China;
2. College of Materials and Mineral Resources, Xi’an University of Architecture and Technology, Xi’an 710055, China）
Abstract:The SiCf/SiC composites containing PyC interphase were prepared by chemical vapor infiltration process. The influences of thermal oxidation on the complex permittivity and microwave absorption properties of SiCf/SiC composites were investigated in the frequency range of 8.2-12.4 GHz. Both the real and imaginary parts of the complex permittivity decreased after thermal oxidation. The composites after 100 h thermal oxidation showed that reflection loss exceeded -10 dB in the frequency of 9.7-11.9 GHz and the minimum value was -11.4 dB at 11.0 GHz. The flexural strength of composites decreased but fracture behavior was improved obviously after thermal oxidation. These results indicate that the SiCf/SiC composites containing PyC interphase after thermal oxidation possess good microwave absorbing property and fracture behavior.
Key words: SiCf/SiC composites; thermal oxidation; dielectric properties; microwave absorbing; mechanical properties
