powder from tires was synthesized following a process based on a plasma method using quartz sand and char from gasification of waste tires as silica and carbon sources respectively. Synthesis and purification conditions are described elsewhere. In order to achieve high sintered density yttria and alumina were added to T-SiC powder as sinering aids, taking into account the residual alumina contained in the synthesized powder (0.5 wt%). Mixing in ethanol was performed by Turbola mixer, then the mixture was dried and sieved. Comercially available ready-to-press a-SiC powder (C-siC) for liquid-phase sintering with appropriate amounts. The main characteristics of T-SiC and C-SiC powder are reported in Table 1. Discs of both T-SiC and C-SiC with diameter of 40 mm and thickness of 3 mm were prepared by uniaxial pressing at 100 MPa followed by cold isostatic pressing at 200 MPa. Sintering was performed in a graphite resistance high temperature furnace in flowing aegon at 1 atm. Sintering for T-SiC was conducted at 1925 C for 0.5 h, while for C-SiC was done at 1930 C for 1 h. Both sintering processes were condcted without sintering bed.