Ceramic particle reinforcement can be used to improve the surface properties of Ti6Al4V (Ti64) alloy. Powder metallurgy route is a promising method to fabricate such reinforced Ti64 components. To assess the relevance of this technique, this work investigates the effect generated by the addition of TiN particles in Ti64 powder during free sintering. TiN reinforcement particles were randomly distributed in the Ti64 matrix with three different concentrations in two configurations: completely reinforced and unreinforced-reinforced bilayer. Dilatometry was used to obtain the shrinkage kinetics of samples at 1200, 1300 and 1400°C under inert atmosphere and to investigate the impact of reinforced particles on the sintering behaviour. The microstructure of sintered materials was shown to be lamellar in the unreinforced material and equiaxed in reinforced materials. Finally, the Vickers microhardness measurement showed the huge benefit of adding TiN particles to increase the mechanical strength of the Ti64 alloy.

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A new processing route is proposed to produce graded porous materials by placing particles of Ti6Al4V with different sizes in different configurations to obtain bilayer samples that can be used as bone implants. The sintering behavior is studied by dilatometry and the effect of the layers’ configuration is established. To determine pore features, SEM and computed microtomography were used. Permeability is evaluated by numerical simulations in the 3D real microstructures and the mechanical properties are evaluated by compression tests. The results show that a graded porosity is obtained as a function of the size of the particle used. The mechanical anisotropy due to the pore size distribution and the sintering kinetics, can be changed by the particle layer arrangements. The Young modulus and yield stress depend on the relative density of the samples and can be roughly predicted by a power law, considering the layers’ configuration on the compression behavior. Permeability is intimately related to the median pore size that leads to anisotropy due to the layers’ configuration with smaller and coarser particles. It is concluded that the proposed processing route can produce materials with specific and graded characteristics, with the radial configuration being the most promising for biomedical applications.

We present a novel Ti64/20Ag highly porous composite fabricated by powder metallurgy for biomedical applications and provide an insight into its microstructure and mechanical proprieties. In this work, the Ti64/20Ag highly porous composites were successfully fabricated by the space holder technique and consolidated by liquid phase sintering, at lower temperatures than the ones used for Ti64 materials. The sintering densification was evaluated by dilatometry tests and the microstructural characterization and porosity features were determined by scanning electron microscopy and computed microtomography. Permeability was estimated by numerical simulations on the 3D real microstructure. Mechanical properties were evaluated by simple compression tests. Densification was achieved by interparticle pore filling with liquid Ag that does not drain to the large pores, with additional densification due to the macroscopical deformation of large pores. Pore characteristics are closely linked to the pore formers and the permeability was highly increased by increasing the pore volume fraction, mainly because the connectivity was improved. As expected, with the increase in porosity, the mechanical properties decreased. These results permitted us to gain a greater understanding of the microstructure and to confirm that we developed a promising Ti64/20Ag composite, showing E of 7.4 GPa, σy of 123 MPa and permeability of 3.93 × 10−11 m2. Enhanced adaptability and antibacterial proprieties due to Ag were obtained for bone implant applications.