含Mo金属陶瓷微波吸收材料的制备与性能

摘要

以Mo、AlN以及TiO2粉末为原料,添加适当的烧结助剂,制备出成形混合料,通过模压成形和烧结分别得到了不同Mo含量的Mo/AlN和Mo/TiO2金属陶瓷烧结体.采用X射线衍射仪、扫描电镜、万能材料试验机和矢量网络分析仪等对烧结体的相组成、显微组织、力学性能和微波吸收性能等进行测试分析.结果表明:Mo/AlN和Mo/TiO2成形压坯分别在1 750℃和1 350℃下烧结4h,可以获得相对密度分别高于97％和94％的Mo/AlN和Mo/TiO2金属陶瓷.Mo/AlN金属陶瓷的力学性能随Mo含量的增加而提高,而Mo/TiO2金属陶瓷的力学性能随Mo含量的增加先升高后降低.Mo的加入明显改善AlN和TiO2陶瓷的微波吸收性能,含40％Mo(质量分数)的Mo/AlN和Mo/TiO2试样在14～18 GHz频率范围最大反射衰减量分别达到22 dB和19dB.%Mo/A1N and Mo/TiO2 cermets were manufactured by a conventional pressing-sintering process using Mo, A1N and TiO2 as raw materials. The phase composition, microstructure, mechanical and microwave-absorbing properties of the sintered cermets were characterized by XRD, SEM, universal testing machine and network analyzer, respectively. The results show that Mo/AIN and Mo/TiO2 cermets with relative density of more than 97% and 94% can be obtained by sintering their compacts at 1 750 ℃ and 1 350 'C for 4 h, respectively. While the mechanical properties of the Mo/AIN cermets increase with Mo contents increasing, the mechanical properties of the Mo/TiO2 cermets first increase and then decrease with Mo content increasing. Mo addition improves the microwave-absorbing behaviors of A1N and TiO2 ceramics. Mo/AIN and Mo/TiO2 samples with 40% Mo (mass fraction) show a maximum reflection loss of 22 Db and 19 Db, respectively, in the frequency range of 14-18 GHz.