This study presents a methodology to fabricate Ti6Al4V cylindrical compacts with a highly porous core and dense shell with the aim to mimic the bone microstructure. Compacts with different core diameters were obtained via conventional pressing and sintering. Large pores were created with the aid of pore formers. Dilatometry was used to determine the sintering kinetics, while X-ray computed tomography was used for characterization. Also, the permeability was evaluated on the 3D microstructure, and the mechanical strength was evaluated via compression tests. The results indicated that sintering was constrained by the different densification rates of the porous and dense layers. However, defect-free compacts were obtained due to neck bonding between the Ti6Al4V particles. Large pores were located in the designed core with a similar pore size distribution. The permeability increased following a power law as a function of the pore volume fraction. The porous core drove the stiffness of the bilayer components, while the combination of both layers increased their strength. The bilayer materials showed permeability (1.36 × 10⁻¹⁰ m²), mechanical properties (E = 6.83 GPa and σ_y = 299 MPa), and admissible strain (σ_y/E = 43 × 10⁻³) similar to those of human bones.

The focus of this work is to analyze the sintering kinetics of Ti12.5Ta12.5Nb alloy by dilatometry. The mixture of powders was achieved by mixing individual powders of Ti, Ta and Nb, which were then axially pressed. Sintering was performed at 1260 °C using different heating rates. The microstructure was determined by X-ray diffraction and scanning electron microscopy. Results show that densification is achieved by solid state diffusion and that the relative density increased as the heating rate was slow. Due to the full solubility of Ta and Nb in Ti, the relative density reached was up to 93% for all samples. Activation energy was estimated from the densification rate and it was determined that two main diffusion mechanisms were predominant: grain boundary and lattice self-diffusion. This suggests that Ta and Nb diffusion did not affect the atomic diffusion to form the necks between particles. The microstructure shows a combination of α, β and α′, and α″ martensitic phases as a result of the diffusion of Ta and Nb into the Ti unit cell. It was concluded that the heating rate plays a major role in the diffusion of Ta and Nb during sintering, which affects the resulting microstructure.

The influence of reinforcement particle size on the densification behavior, mechanical performance, and thermal expansion of Cu–Al ₂ O ₃ composites processed by powder metallurgy is systematically investigated in this study to elucidate its role in densification kinetics and thermomechanical performance. Although ceramic-reinforced copper composites have been widely studied, the combined effect of particle size across micron- to nanoscale regimes on densification kinetics and thermal expansion remains insufficiently understood. In this work, alumina particles with average sizes of 40 µ m, 1 µ m, and 50 nm were incorporated into spherical copper powders at volume fractions ranging from 3 to 10%. The mixtures were compacted at 500 MPa and sintered at 1000 °C under a reducing atmosphere. Densification was evaluated using geometric measurements and dilatometry, while microstructural features were analyzed by scanning electron microscopy, and mechanical performance was assessed by compression testing. The results demonstrate that particle size critically governs densification mechanisms and final properties. Composites reinforced with coarse alumina particles exhibited higher densities and more homogeneous microstructures, whereas submicron and nanometric particles promoted agglomeration, limiting particle rearrangement, reducing shrinkage, and increasing residual porosity, which in turn decreased the densification rate. Additionally, the coefficient of thermal expansion was reduced by up to approximately 40% compared to pure copper for composites reinforced with coarse particles. These findings highlight that the use of reinforcement particles comparable to or larger than the matrix powders is a key processing strategy to enhance densification and achieve balanced thermomechanical performance in Cu–Al ₂ O ₃ composites.

Copper alloying of Ti6Al4V via liquid-phase sintering (LPS) is a promising route to enhance densification and mechanical properties for biomedical implants. This study investigates the effect of sintering temperature (900–1100 °C) on the densification, microstructure, and electrochemical behavior of Ti6Al4V–20 wt.% Cu composites. Samples were fabricated via pressureless sintering, maintaining a constant relative green density of 72.7%. The results show that the relative density increased progressively from 78.6% at 900 °C to 98.1% at 1100 °C. Microstructural analysis revealed a transition from fragmented Ti-Cu dendritic structures to refined globular intermetallic, with enhanced copper diffusion into the α-Ti matrix above 1000 °C, accompanied by the formation of TiCu and Ti₂Cu intermetallic phases. Correspondingly, microhardness increased systematically from 313 HV to 473 HV, correlated with reduced porosity and intermetallic reinforcement. Electrochemical tests in Ringer’s solution indicated that while higher temperatures improve structural integrity, the distribution of Cu-rich phases significantly influences corrosion kinetics. These findings demonstrate that sintering at 1100 °C optimizes the densification–microstructure relationship, providing a technical basis for the development of high-performance Ti-based composites. Based on previous studies of Ti–Cu systems, these materials may exhibit antibacterial activity, although no biological or antibacterial tests were performed in the present work.

This study presents a methodology to fabricate Ti6Al4V cylindrical compacts with a highly porous core and dense shell with the purpose to mimic the bone microstructure. Compacts with different core diameters were obtained by conventionally press and sintering. Large pores were created with the aid of pore formers. Sintering kinetics was determined by dilatometry, whereas characterization was performed by X-ray computed tomography. Also, permeability was evaluated on the 3D microstructure and the mechanical strength was evaluated by compression tests. Results indicated that sintering is constraint by the different densification rates of the porous and dense layers. Nonetheless, defectless compacts were obtained due to neck bonding between Ti6Al4V particles. Large pores were located in the designed core with similar pore size distribution. Permeability increased following a power law as a function of the pore volume fraction. Stiffness of bilayer components was driven by the porous core, meanwhile, the strength resulted from the combination of both layers. Bilayer materials obtained showed a permeability and mechanical properties, as well as admissible strain (σy /E) similar to those of human bones.