Tape casting and reaction sintering of titanium-titanium oxide-nickel oxide mixtures

Suspensions of a powder mixture of titanium-titanium oxide-nickel oxide were tape cast. Analysis of the green tape showed an increase in Young's modulus and tensile strength with increasing powder volume content ϕ up to 28 vol%; at higher ϕ the properties decreased due to the formation of flaws in the green tape. The elongation of the green tape decreases continuously with increasing ϕ. Green tapes were laminated and were reactively sintered at 1350 °C to form a composite of TiO-NiTi2-Ni3Ti with a porosity of ∼5%. The wetting of TiO by NiTi2 prevented the TiO grains of forming a highly connected network, despite TiO making up 50% of the volume. The mixed intermetallic phases NiTi2 and Ni3Ti did form a continuous network. The three point bending strength of the composites was 121 MPa.