Effect of V content on microstructure and mechanical property of a TiVCuNiAl composite fabricated by spark plasma sintering

Ultrafine-grained (Ti40Cu22.9Ni19.4Al17.7)x(Ti80V20)1−x (x = 0.35 and 0.55) composites were fabricated by spark plasma sintering and crystallization of amorphous phase. Outstanding difference in microstructure and mechanical property is found for the two composites. Microstructure observation shows that the two composites all consist of body-centered cubic β-Ti and face-centered cubic (Cu, Ni)-Ti2 regions but have opposite matrix and reinforcing phases. Meanwhile, mechanical property examination indicates that the composites for x = 0.35 exhibit far higher fracture strength and far larger fracture strain compared with the composites for x = 0.55 fabricated under the same parameter conditions. The different mechanical properties for the two composites can be explained by the different fracture mechanisms resulted from their different microstructures.