AlB12-AlB12C2-TiB2 hard and tough composites synthesized by reactive plasma activated sintering

AlB 12 -AlB 12 C 2 -TiB 2 -based hard and tough composites were fabricated using ball milled B, Al, and Ti powders as the starting materials, and sintered by reactive plasma activated sintering (PAS). The mechanical properties and microstructures were investigated, and the effects of the composition and microstructures on the reinforcing and toughening of the composites were determined. The results showed that the composite with 10 vol% TiB 2 showed excellent mechanical properties, a lightweight of 2.76 g cm −3 , Vickers hardness of 37 GPa, and fracture toughness of 7.1 MPa m 1/2 . In addition, the main strengthening and toughening mechanisms were due to the twin structures, dislocation defects, and stacking faults in the specimen in addition to grain pull-out, crack deflection, crack bridging, and crack branching caused by elongated TiB 2 particles.