Squeeze cast co-continuous TiN reinforced Al matrix composites

The co-continuous TiN reinforced Al matrix composites were fabricated via the squeeze casting of porous TiN preforms obtained by carbothermal reduction. The effect of volume fraction of Al phase on the microstructures and mechanical properties of composites as well as the strengthening and toughening mechanism of composites were investigated. The Vickers hardness and the flexural strength decrease, and the fracture toughness increases with the increase of the Al content of composites. The composites are fractured due to the ductile intergranular rupture of equiaxial TiN grains. The mechanical properties of the composites cannot be affected without the excessive interface reaction between TiN and Al. The strengthening and toughening mechanism of composites is due to the load transferring, dislocation strengthening and crack deflection.