Synthesis and mechanical properties of TiB2/Ti2AlN composites fabricated by hot pressing sintering

TiB2/Ti2AlN composites with different proportions were successfully fabricated through solid state reaction of Ti/Al/AlN/BN powders and subsequent hot pressing sintering. The reaction mechanism, microstructures and mechanical properties of the composites were investigated. The Vickers hardness of the samples ascended with increases in the TiB2 content and reached the highest value of 11.32 ± 0.12 GPa at a TiB2/Ti2AlN mole ratio of 1:2 (M2T1). TiB2/Ti2AlN composites with a mole ratio of 1:3 (M3T1) and 1:4 (M4T1) exhibited the maximum flexural strength of 497 ± 15 MPa and the highest fracture toughness of 9.52 ± 0.14 MPa·m1/2, respectively, which are 1.3 times and 1.8 times that of pure Ti2AlN (MT0) ceramic.