Microstructure and mechanical properties of a three-layer B4C/Al–B4C/TiB2–B4C composite

A three-layer structure material, consisting of B4C/Al, B4C/TiB2 and B4C composites, was obtained using a two-step method for both hot pressing and aluminum infiltration in vacuum. The three-layer B4C/Al–B4C/TiB2–B4C composite showed good interfacial bonding. Before aluminum infiltration the B4C porous layer in the three-layer preform looked like a three-dimensional network of interconnected capillaries. The microstructures of both B4C/TiB2 and B4C layers showed no apparent changes before and/or after aluminum infiltration. The three-layer composite showed improved fracture toughness than that of B4C material and higher comprehensive hardness than that of B4C/Al material.

► A three-layer B4C-B4C/TiB2-B4C porous preform was synthesized by hot pressing.
► B4C porous layer looked like a network of interconnected capillaries.
► A three-layer B4C/Al-B4C/TiB2-B4C composite was prepared by vacuum infiltration.
► The composite showed improved fracture toughness compared to B4C material.