Effects of different carbon sources on the compressive properties of in situ high-volume-fraction TiC x /2009Al composites

Abstract

Effects of carbon sources, i.e. carbon nanotubes (CNTs), graphite, carbon black (C-black), on synthesised TiC _x size, shape and compressive properties of in situ 40–60 vol.-% TiC _x /2009Al composites were investigated. When CNTs and C-black were used, the synthesised TiC _x with particle sizes of 0.08–1 and 0.9–5 µm, respectively, was spherical or nearly spherical in shape, while graphite was used, the synthesised TiC _x with particles sizes of 0.2–2 µm was octahedral or spherical in shape. The yield strength (σ_0.2), ultimate compression strength (σ_UCS) and hardness of TiC _x /2009Al composites all increased with increasing TiC _x content, while the plastic strain (ε) decreased. The σ_0.2, σ_UCS, ε and hardness of 60 vol.-% TiC _x /2009Al composites fabricated by using CNTs were 722 MPa, 946 MPa, 3.2% and 260 ± 10 Hv, respectively. The strength increase of the composites resulted from finer-sized TiC _x particles with spherical shape.