Ti_(3)SiC_(2)粉体的高温抗氧化和微波吸收性能研究

Study on high temperature oxidation resistance and microwave absorption properties of Ti_(3)SiC_(2)powders

Ti_(3)SiC_(2)(TSC)因其良好的导电性和耐高温性能在高温微波吸收领域备受关注。以单质Ti粉、Si粉和石墨粉为原料,通过高温固相反应在1400℃下反应3 h制备了TSC粉体,并借助XRD和XPS等分析其组成,通过热重分析仪、矢量网络分析仪表征其高温抗氧化和微波吸收性能。研究表明:通过高温固相反应所制备的TSC粉体中杂质相主要包括SiC、SiO_(2)、TiO_(2)和TiC。TSC粉体在低于400℃环境中具有良好高温抗氧化性能。当TSC与石蜡的混合物的厚度为2.0 mm时,含有60%(质量分数)TSC的复合材料有效吸收带宽为0.9 GHz(17.10~18.0 GHz)。当TSC含量提升至70%,其有效吸收带宽扩展为3.86 GHz(12.95~16.81 GHz)。当TSC含量进一步提升至80%,其有效吸收带宽降低至1.44 GHz(9.37~10.77 GHz)。

Ti_(3)SiC_(2)(TSC)is of great interest in the area of high-temperature microwave absorption because of its good electrical conductivity and high thermostability.In this paper,TSC powders were prepared by high-temperature solid-state reaction at 1400℃for 3 h.The experimental raw materials were Ti powder,Si powder and graphite powder.Its composition and phase were analyzed by XRD and XPS.Further,its high temperature oxidation resistance and microwave absorption properties were characterized by thermogravimetric analyzer and vector network analyzer.The results show that the impurity phases in TSC powders mainly include SiC,SiO_(2)TiO_(2)and TiC.TSC powders can maintain good high-temperature oxidation resistance below 400℃.When the thickness of the mixture of TSC and paraffin is 2.0 mm,the effective absorption bandwidth(EAB)of the composite containing 60%(mass fraction)TSC is 0.9 GHz(17.10-18.0 GHz).When the TSC content is increased to 70%,the EAB is expanded to 3.86 GHz(12.95-16.81 GHz).When the TSC content is further increased to 80%,its EAB decreases to 1.44 GHz(9.37-10.77 GHz).