Comparing the effects of different sintering aids on spark plasma sintering of SiC ceramics

Abstract

In the present work, to improve the mechanical properties of silicon carbide different sintering aids were used. 2.5 wt% B4C, 2.5 wt% AlN, and TiC in the 5 to 7 wt% range were selected to manufacture the SiC-based sample via spark plasma sintering at 1700 °C. The results show that the use of 2.5 wt% B4C-2.5 wt% AlN additives increases the strength (1206 MPa) of the composite through the compressive stress created in the grain boundaries and decreases its fracture toughness (5.13 MPa.m1/2). But in the case of TiC-doped SiC, the toughness (7.09 MPa.m1/2) and density (3.18 g/cm3) of the sample increases compared to the pure SiC sample.