Effect of in-situ synthesized TiB2 on microstructure and mechanical property of Al/TiB2-SiC interpenetrating phase composites

Abstract

Al/TiB2-SiC composites were prepared based on TiB2-SiC porous ceramic preforms. The advantages of this work were characterized by the in-situ synthesized TiB2 in porous ceramic preforms which directly formed interconnected pores as well as TiB2-SiC ceramic skeletons during the one-step ceramic sintering. By controlling in-situ synthesized TiB2 volume fraction, it is possible to tailor TiB2-SiC preform structures so as to determine the structures and mechanical properties of Al/TiB2-SiC composites. The porous ceramic preforms with 20 vol% TiB2 addition achieved the highest porosity, the biggest pore size, but the lowest flexural strength. Al/TiB2-SiC composite with 20 vol% TiB2 addition showed the optimum mechanical properties. The improvement of mechanical properties of Al/TiB2-SiC composites was mainly ascribed to TiB2 additions as well as dense composite structures which were fully infiltrated with Al. This special interpenetrating structural feature and TiB2 addition also constituted an improved toughness through complex crack patterns such as branching, bridging, and deflection.

Keywords

• Al/TiB2-SiC composite
• in-situ synthesized TiB2
• porous ceramic
• microstructure
• mechanical property