Structure and mechanical properties of Ti-6Al-4V with a replicated network of elongated pores

Ti-6Al-4V, with a network of elongated, open pores aligned along two perpendicular directions, is produced by a two-step replication process: (i) Ti-6Al-4V powder or foil preforms containing low-carbon steel wire meshes are densified by hot pressing under transformation superplasticity conditions; (ii) porosity is created by electrochemical dissolution of the low-carbon steel wires and the adjacent Fe-containing Ti-6Al-4V matrix. If high-carbon steel wires are used, Fe diffusion into Ti-6Al-4V is inhibited by a carbide layer forming at the wire/matrix interface, and pores exactly replicate the shape of the wires. Ti-6Al-4V with ∼19% and 34% porosity, without and with Fe-Ti interdiffusion respectively, shows low oxygen contamination and good compressive ductility. Strength and stiffness, as measured by compression testing and ultrasonic measurements, are compared with simple analytical models and numerical finite-element models.