短切SiC纤维含量对SiC_(sf)/LAS复合材料性能的影响

用热压烧结法制备了不同纤维含量的SiCsf/LAS玻璃陶瓷复合材料,研究了该复合材料的微观结构、力学性能和微波介电性能。结果表明:随着SiC纤维含量的增加,SiCsf/LAS材料的抗弯强度先增加后降低,最大值为104MPa。由于碳界面层的形成,SiCsf/LAS比LAS具有更高的介电常数。当SiC短切纤维的质量分数为1.5%时,SiCsf/LAS复合材料介电常数具有最大值,其实部ε′和虚部ε″均值分别为48和66,并具有明显的频散效应。

Effect of Short SiC Fibres Content on the Properties of SiCsf/LAS Composite

The SiCsf/LAS glass ceramic composites with different content of SiC fibers were prepared by hot-press sintering.The microstructure,mechanical and microwave dielectric properties of the composites were investigated.Results show that the flexural strength of the composites increases firstly,and then decreases as the content of SiC fiber increases,with a maximum value of 104 MPa.Because of the formation of carbon interface between the fiber and matrix,all the SiCsf/LAS composites have greater values of permittivity than LAS.When the content of short SiC fibre is 1.5%,the SiCsf/LAS composite has the maximum permittivity,of which the average values of real part ε' and imaginary part ε″ are 48 and 66 respectively,and reveals a significant effect of frequency response.