EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

The CoCr and Grade-23 Titanium alloys are two of the most used materials in dental and orthopaedic applications. However, “stress-shielding” (difference between bone and implant rigidity causing bone resorption and implant failure) issues and European change in the CMR (carcinogenic, mutagenic, and toxic to reproduction) classification of elements such as cobalt constitute challenges in the design and the elaboration of a new generation of fully biocompatible metallic alloys. Consequently, it was developed in the present work a new low-modulus β-type Ti-alloy by additive manufacturing, thanks to the in-situ powder bed fusion elaboration technique that consists in the powder bed fusion of a blend of elemental powder of a targeted composition.
In this presentation, the Ti-6Al-4V alloy and the new β-Ti alloy manufactured by powder fusion will be presented and compared in term of their mechanical properties. As the parts experienced growth layer by layer, internal stress tends to appear linked to the huge thermal gradient. Heat treatment is the most common way used to reduce and eliminate this kind of thermal stress, which can be detrimental to the as-build mechanical characteristics. Influence of the heat-treatment atmosphere (under vacuum of under air) during relaxation treatment on the mechanical properties is investigated. Finally, mechanical, and structural characteristics of a new fully β-Ti alloy, elaborated by in-situ powder bed fusion will be presented, and compared to the characteristics of the previous heat-treated Ti-6Al-4V alloy in order to conclude briefly on the capability of powder bed fusion process to produce new alloys with interesting properties for dental and orthopaedic applications.