C/C-SiC composites were prepared by gaseous silicon infiltration (GSI) using C/C as green body. The effect of C/C density on the phase composition

friction and wear properties was studied. Through analyzing the braking process

the friction and wear mechanism of C/C-SiC composites is discussed in detail. The results show that

with C/C green density increasing

the density of GSI C/C-SiC composites decreases

and C content and open porosity gradually increase

while the contents of SiC and residual Si decrease. Under the self-dual circumstances

the average friction coefficient and wear rate of the composites increase firstly and then decrease

however

the braking stability coefficient increases continuously. When the density of C/C is 1.25g/cm3

the average friction coefficient and wear rate reach the maximum value. The braking process mechanism of GSI C/C-SiC composites is controlled by furrow effect and adhesion effect. The furrow effect is the main part in initial stage and late stage of braking

while the adhesion effect is the main factor in the middle stage.