Fabrication of Ti-Nb Sheets by Tape Casting

Tape casting is a cost effective and fully automated method for production of ceramic and metal sheets, which has been largely used in the ceramic industry. Tape casting can be an attractive route for manufacturing less ductile metals as titanium alloys. Ti-Nb alloys are highlighted due their combination of corrosion resistance, strength and creep resistance at higher temperatures, however they difficult and expensive o process by the conventional forming route. In this context, we introduced tape casting as manufacturing route of Ti-Nb sheets. Ti-Nb sheets were produced by tape casting of elemental Ti powder with addition of 10 and 17 wt.% of Nb powders. The position of doctor blade was adjusted to achieve a thickness of ca. 350 μm in the sintered state. Sintering was performed under vacuum at 1100 °C, 1150 °C, 1200 °C and 1300 °C. The effect of sintering temperature was investigated by scanning electron microscopy (SEM), chemical analysis and X-ray diffraction. As expected higher sintering temperature enhanced Ti and Nb interdiffusion, which increased the amount of β- phase. A homogeneous (α + β)-type alloy with low residual porosity of ca. 1.5 vol.% was achieved in the Ti_10Nb tape sintered at 1300 ºC. Preliminary tensile testes demonstrated that porosity has a strong effect on the stress-strain behavior. A tensile strength of 660 MPa and Young Modulus of 29 GPa were obtained in the Ti_10Nb sheets. In summary, tape casting has been successfully applied to produce both dense and porous Ti-Nb sheets, which have the potential to be used in structural aerospace components such as sandwich panels.