Improvement of mechanical and dielectric properties of PIP-SiCf/SiC composites by using Ti3SiC2 as inert filler.

In order to optimize the mechanical and dielectric properties of SiC f /SiC composites, Ti 3 SiC 2 was introduced into the composites by a modified precursor infiltration and pyrolysis (PIP) process. The results reveal that the appropriate Ti 3 SiC 2 content in the infiltration precursor can effectively enhance the infiltration efficiency and decrease the open porosity of SiC f /SiC composites. The maximum flexural strength of the composites reaches 273 MPa when the Ti 3 SiC 2 content is 9 wt%, which is 131% higher than that of the composites without filler (118 MPa). This is mainly attributed to the high density and suitable interfacial bonding of the composites with the Ti 3 SiC 2 filler. Both the ε ′ and ε ″ values of SiC f /SiC composites show a monotonically increasing tendency from 13.5–16.5 and i 15– i 19 to 27.5–32.5 and i 31.5– i 39 with the Ti 3 SiC 2 content increase from 0 to 15 wt%. Especially, the conductivity and complex permittivity of the composites display a relative large increasing extent for Ti 3 SiC 2 content exceeding 9 wt% owing to the percolation threshold effect. [ABSTRACT FROM AUTHOR]