Powder metallurgy of the porous Ti-13Nb-13Zr alloy of different powder grain size

The objective of the present project was to determine the effects of powder granulation (fraction of grain size) for the Ti-13Nb-13Zr alloy, produced by powder metallurgy, on its porosity, grain cohesion, compressive strength, and Young`s modulus. Two powder fractions, 45–105 µm, and 106–250 µm were applied. The 50 mass pct of NH<sub>4</sub>HCO<sub>3</sub> was added as a space holder. The specimens were in compaction stage uniaxially pressed at pressure 625 MPa for 120 s. The brown bodies were sintered at a temperature 1150°C for 3.5 h. The well-joined grains were observed for both powder granulations. The increase in powder granulation resulted in an increase of porosity from 51% to 59%, and it was only 30% with no space holder used. The compressive strength increased with decreased porosity from 57 to 236 MPa. Young`s modulus was measured as 4.8 GPa for finer powder and 0.9 GPa for coarser powder. It is evident from the results obtained that the applied process parameters, the space holder and its fraction, and the use powder granulation between 45 and 105 µm bring out the porous material fulfilling mechanical and biological requirements specific of load-bearing titanium implants.