2010 Volume 118 Issue 1381 Pages 810-813
The effect of additive incorporation in porous self-bonded SiC (SBSC) ceramics fabricated from a mixture of coarse SiC powder (∼65 µm), Si and C is investigated here. Generally, it was found that the additive reduced the porosity and increased the flexural strength of the SBSC ceramic material. This was consistent with the presence of necking in the ceramic microstructure. The flexural strength of the material without additive (control sample) was ∼16–17 MPa and this was found to be enhanced up to ∼33 MPa using 2 wt % B and ∼38 MPa, using a mixture of 1 wt % Al + 1 wt % B. Thus, the porous SiC ceramic with Al–B additive (typical flexural strength ∼38 MPa at 42% porosity) is very promising, contrasting its mechanical properties with the cost-effectiveness of the raw materials.