Effect of initial powder particle size on permeability and corrosion behavior of biomedical porous Ti6Al4V alloy prepared by powder metallurgy technique

In this work, the influence of initial powder particle size on the properties of biomedical porous Ti6Al4V alloys prepared by the space holder method was investigated. The results show that the particle size of the initial powders has a strong impact on the permeability, mechanical properties and corrosion behavior of the obtained porous Ti6Al4V alloys. When the mean particle size increases from dm ~ 17 ?m to dm ~ 43 ?m, the permeability of the resulted alloys increased about 47 folds, from 6.74?10-13 to 3.15?10-11 m2. On the contrary, the yield strength and modulus decreased from 207 MPa and 4.52 GPa to 98.1 MPa and 3.1 GPa, respectively. In this process, the macropores are defined by the space holders, the micropores presented on the cell walls are generated from partial sintering of powders which have an important role in the enhancement of the connectivity between macropores, porosity and hence, the permeability of porous materials. It is found that using the bigger particles led to the higher corrosion current density, Icorr due to the increase of the contact area with the simulated body fluid solution.