Density of the sample was determined by the Archimed method (ASTM C373). Polished and plasma etched (70%CF4-30%O2) sintered SiC samples were observed using scanning electron microscopy (SEM,LEO 438-VP). X-ray diffraction (XRD) analysis was used to determine the qualitative composition in terms of crystalline phases of the sintered samples. X-ray patterns were collected with a Philips powder diffractometer with a Bragg-Brentano geometry and equipped with a copper anode operated at 40 kV and 30 mA (step 0.02 , time 6 s). The phase analysis was carried oyt with the PC x'pert High Score software Veesion 2.2a (PANalytical B.V., Almelo, the Netherlands).