Pressureless Sintering of Alumina‐Titanium Carbide Composites

The densification of Al 2 O 3 ‐TiC composites is detrimentally affected by chemical reactions between Al 2 O 3 and TiC. These reactions must be suppressed in order to promote sintering. In this study, the specific reactions occurring in Al 2 O 3 ‐TiC composites were modeled, using thermodynamic calculations, and verified by experiments. The reaction between Al 2 O 3 and TiC was suppressed by the use of specially prepared embedding powders allowing pressureless sintering to closed porosity. The Al 2 O 3 ‐TiC composites were subsequently hot isostatically pressed to > 99% of theoretical density without encapsulation. Typical flexural strength and fracture toughness of Al 2 O 3 ‐30 wt% TiC composites were 690 MPa and 4.3 MPa · m 1/2 , respectively.