Design and Fabrication of Novel Titanium-Rhenium Alloys for Aerospace Applications

The increasing demand for lightweight materials in air, land, and sea transportation arises from the need to reduce costs associated with fuel consumption and greenhouse gas emissions, which contribute to worldwide global climate change. Our research focuses on ab initio designing, casting, atomisation, and Laser Beam Powder Bed Fusion (PBF-LB) processing new titanium alloysSpecifically, we aim to enhance the properties of these alloys by incorporating rhenium, thereby, making them suitable for high-temperature and aggressive environments.

Existing research indicates that rhenium is a versatile element that limits diffusion processes and significantly inhibits titanium alloys' oxidation. Titanium-rhenium (Ti-Re) alloys are important for modern lightweight materials required in high-temperature applications. The market lacks effective lightweight solutions due to the low melting points of aluminium and magnesium alloys and the limited structural stability and oxidation resistance of the titanium alloys available today. In contrast, nickel, currently used in high-temperature applications, is considerably more expensive and has nearly double the density of titanium, leading directly to increased fuel consumption.

In our research, we developed Ti-Al-Si-Re alloy using ab initio methods, which was subsequently cast using an arc melting system and atomized through gas atomization. The fabricated powder was then processed in the PBF-LB process using an Aconity 3D GmbH device, varying the many process parameters (laser power, scanning speed and strategy, etc.) and substrate heating temperatures from room temperature (RT) to 700°C. The alloy demonstrates a strength at 625°C that exceeds Inconel 625. In addition, other results concerning porosity, phase composition, and mechanical testing at elevated temperatures indicate a promising potential for utilizing Ti-Re alloys in hot section (e.g. turbine) of jet engines.