Wear-mechanical properties of filler-added liquid silicon infiltration C/C–SiC composites

A carbon fiber reinforced silicon carbide matrix (C/C–SiC) composites material was manufactured by introducing a filler into the liquid silicon infiltration (LSI) process. The filler consisted of Si:Carbon black = 1:1 mixed with a phenol resin. Use of the filler resulted in a negligible reduction in the residual free Si of approximately 0.7% but increased 15% of reacted SiC amount. Dilatometer and X-ray diffraction (XRD) evaluations also confirmed improved formation of reaction-bonded silicon carbide (SiC) in the matrix. The wear rate was decreased more than 2.5-fold, indicating significantly improved wear-resistance properties. However, flexural strength gradually decreased and fiber damage was observed in fracture surface with increases in filler content.

► Filler addition increased SiC portion in C/C–SiC composite.
► Wear resistance dramatically increased by adding filler in C/C–SiC composite.
► Free Si amount was not affected by filler addition.