Mechanically enhanced novel Ti-based alloy foams obtained by hot pressing

Ti-based alloys are being widely used as bio-implant materials because of their excellent properties. This work reports the synthesis of Ti–30Nb–13Ta–2Mn (wt. %) foams with and without bimodal microstructure using NaCl (0, 20 and 30 vol %) as space-holder particles (SHP). Samples with bimodal microstructure were obtained by mixing milled and un-milled powders in a proportion of 1:4. Samples without bimodal microstructure were synthesized using only un-milled powders. Hot pressing was used to consolidate the green samples using argon gas as protective atmosphere under 30 MPa at 780 °C for 30 min. The consolidated metallic foams were characterized by optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) to study their microstructure and phase analyses. The Young's modulus values were between 39 and 19 GPa, and the yield strength values were obtained between 180 and 400 MPa. From the mechanical properties point of view, samples with bimodal microstructure and with 20 and 30 vol % of NaCl have a great potential to be explored for biomedical applications due to their mechanical properties of Young's modulus smaller than 30 GPa and yield strength higher than 180 MPa. Further, the foams were modelled using finite element analysis (FEA) with random distribution of the pores in order to estimate the compressive behavior, and the Young's modulus measured using FEA was in an excellent agreement with the experimental data.