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 SiCf/SiC composites, Ti3SiC2 was introduced into the composites by a modified precursor infiltration and pyrolysis (PIP) process. The results reveal that the appropriate Ti3SiC2 content in the infiltration precursor can effectively enhance the infiltration efficiency and decrease the open porosity of SiCf/SiC composites. The maximum flexural strength of the composites reaches 273 MPa when the Ti3SiC2 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 Ti3SiC2 filler. Both the epsilon' and epsilon '' values of SiCf/SiC composites show a monotonically increasing tendency from 13.5-16.5 and i15-i19 to 27.5-32.5 and i31.5-i39 with the Ti3SiC2 content increase from 0 to 15 wt%. Especially, the conductivity and complex permittivity of the composites display a relative large increasing extent for Ti3SiC2 content exceeding 9 wt% owing to the percolation threshold effect. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.