Machinable and mechanical properties of sintered Al₂O₃-Ti₃SiC₂ composites

Abstract

Two-phase composites consisting of (1 − x) Al₂O₃ and xTi₃SiC₂ (x = 0−1) were prepared by spark plasma sintering (SPS). Sintered densities larger than 98% of theoretical density were achieved when the specimens were sintered at 1300°C for 5 min (in vacuum, at pressure 30 MPa). When content of Ti₃SiC₂ increased up to 30 wt%, composites were found to be machinable—they could be drilled easily using conventional Fe-Mo-W drills or gravers. The mechanical properties of the (1 − x) Al₂O₃−xTi₃SiC₂ composites were evaluated. The bending strength, Vickers hardness of the specimens had the following ranges: 428 ± 10.2 (x = 0) to 673 ± 15.4 Mpa (x = 1) (bending strength at room temperature); 19.9 (x = 0) to 4.0 GPa (x = 1) (Vickers hardness).