Recent Studies and Developments in Titanium Biomaterials

Titanium and its alloys have a high specific strength, excellent corrosion resistance, and good biocompatibility. Therefore, these alloys are adopted as raw materials for artificial bones and joints. Furthermore, these alloys are used as materials for dental surgery. In the development of alloy design, beta-type titanium alloys that possess a lower Young’s modulus than other types of titanium alloys, e.g., Ti-6Al-4V alpha-beta-type alloys, are being actively investigated worldwide. Based on these studies, titanium-niobium-tantalum and zirconium system alloys were developed. For example, Ti-29Nb-13Ta-4.6Zr alloy has a low Young’s modulus, excellent biocompatibility, and improved mechanical properties. Many researchers are actively investigating surface modifications and surface treatments. Additive manufacturing, namely 3D printing, wherein metal powders are piled up layer by layer to produce goods without a mold, has attracted attention in many fields, including manufacture of implants, especially porous structural implants with a low Young’s modulus. It is very important that titanium and its alloys be applied to health-care goods, e.g., wheelchairs and prostheses. Therefore, we herein consider four topics: alloy development, coating and surface modification, additive manufacturing, and health care applications

Quantitative assessment of liquid Ga penetration into an aluminium alloy by high-resolution X-ray tomography

International audienceWe have evaluated the liquid Ga penetration into an aluminium alloy by high-resolution X-ray tomography. The 3D visualization of a crack together with its surrounding grain structure was performed with the help of the Ga penetration technique. It is found that the advance directions of the crack-tip were strongly influenced by the grain microstructure and the branching of the crack is affected by grain distribution. In this study, the liquid Ga not only acts as a contrast agent for grain boundaries, but also expands the volume of the Al alloy due to Ga diffusion and associated processes. The 3D strain between the grains has been determined by microstructural gauging technique, which uses micropores as marker points. The 3D expansion of the sample volume, the volume reduction of micropores and the brittle fracture were evidently observe