Synthesis and characterisation of Ti6Al4V/xTa alloy processed by solid state sintering

ABSTRACT

This work investigates the effect of Ta particle addition into a Ti6Al4V alloy processed by solid state sintering. The volume fraction of Ta ranged between 0 and 30 vol.-%. The sintering kinetics of powder mixes are evaluated by dilatometry. Sintered materials are characterised by SEM and XRD, and their mechanical properties are obtained from microhardness and compression tests. Sintering behaviour and final microstructure are affected by Ta particles, which slow down the densification, lower the temperature of α-to-β phase transition and stabilise the β phase. Mechanical properties, as microhardness, Young’s modulus and yield stress, depend on the microstructure reached after sintering and on the residual porosity. An equation expressing the Young’s modulus of Ti6Al4V/xTa alloy as function of x and porosity is proposed and validated. The materials with at least 20 vol.-% of Ta exhibited a high strength to modulus ratio, which is suitable for orthopaedic implants.

KEYWORDS:

• Sintering kinetics
• Ti6Al4V/Ta alloy
• compression tests, microhardness, microstructure
• porosity

Acknowledgments

The authors would like to thank CIC of the UMSNH and ECOS M15P01 for providing the facilities to develop this study. It is grateful for Grenoble INP for funding one of his stays at SIMAP laboratory.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes on contributors

L. Olmos is a research professor at Michoacana University in Mexico, where he specializes in sintering of titanium and titanium composites for biomedical applications.

J. L. Cabezas-Villa is a PhD student working on sintering of heterogeneous powders systems.

D. Bouvard is a Professor with a wide research experience on the thermo-mechanical behaviour of powders and granular materials, mechanical and microstructural characterization, X-ray microtomography, multiscale modelling and numerical simulation, forming, sintering.

J. Lemus-Ruiz is a research professor at Michoacana University in Mexico specialized on sintering of composites and joining of dissimilar materials.

O. Jiménez is a research professor at the Guadalajara University who specializes in mechanical behavior of coatings fabricated by PVD and sintering powders.

L. A. Falcón-Franco is a research professor at Coahuila Autonomous University specialized on the mechanical behavior of composites materials.

ORCID

L. Olmos http://orcid.org/0000-0001-7399-2643

L. A. Falcón-Franco http://orcid.org/0000-0002-2789-6164

Additional information

Funding

The authors would like to thank Coordination of the scientific research (CIC) of the UMSNH and ECOS M15P01 for their financial support.