Effects of Ti foil thickness on microstructures and mechanical properties of in situ synthesized micro-laminated TiC/Ti composites

Abstract

In situ micro-laminated TiC/Ti composites were fabricated by hot-pressing alternatively stacked graphite and Ti foils. With increase in the original thickness of Ti foils, the thickness (i.e., volume fraction) of Ti layers in the composites increased, whereas the thickness of TiC layers remained relatively constant. The flexural strength and fracture toughness of composites also increased with increase in the original thickness of Ti, and the maximum fracture toughness was 35.27 MPa*m1/2. Nevertheless, the compressive strength of composites decreased with increase in the original thickness of Ti along both the perpendicular-to-lamellar direction and the parallel-to-lamellar direction. However, different failure modes and much higher compressive strength along the parallel-to-lamellar direction than along the perpendicular-to-lamellar direction highlight the anisotropy of the composites in compressive properties. By tailoring the original thickness of Ti foils, the mechanical properties of the laminated TiC/Ti composites can be controlled without changing the phase structure, chemical composition, and the thickness of the brittle TiC layers.