Australian Engineers Develop Innovative Floating Titanium Material for Marine Use
In a groundbreaking achievement, engineers from Australia have successfully developed a new type of titanium material that can float on water, even sustaining severe damage. This advancement opens exciting possibilities for enhancing marine infrastructure.
The team at RMIT University revealed that their creation is a 3D-printed titanium lattice structure, which consists of hollow, interconnected struts filled with polyurethane foam. Not only does this innovative material float, but it also shows impressive durability against seawater exposure, proving to be stronger than stainless steel and high-density plastic commonly used in marine applications like jetties and buoys.
Dr. Jordan Noronha, the lead researcher at RMIT’s Centre for Additive Manufacturing, explained that this work addresses a significant challenge in making metal lattice structures buoyant. Typically, while these metallic lattices can be incredibly lightweight, their open designs allow water to seep in, causing them to sink. However, the new design keeps the floating capability intact even after undergoing substantial damage.
“To keep these structures afloat, we filled only the hollow titanium struts with foam, which enables water to flow through while maintaining buoyancy,” Dr. Noronha noted.
The study marks a first-of-its-kind demonstration of a floating metal-hybrid lattice metamaterial. Notably, samples floated in freshwater for over two months, showcasing their sustained buoyancy.
To achieve this breakthrough, the researchers introduced a new concept called “skeletal density” to predict the floating ability of open structures. Traditional density calculations often include all open spaces, which are filled by water and do not support buoyancy. In contrast, skeletal density focuses solely on the parts of the structure that exclude water, allowing for a more accurate prediction of buoyancy.
“If the skeletal density is lower than that of the liquid around it, the structure will float, even with water flowing through its openings,” Dr. Noronha explained.
Testing revealed that the titanium lattice was about 70 percent stronger than the materials usually employed in marine contexts, which means it could withstand harsher conditions. Additionally, when tested in natural seawater, the material lost only a tiny fraction of its weight and maintained its strength after immersion.
Crucially, even after sustaining considerable damage, including cracks and breaks, the structure managed to stay afloat. It was only when significantly crushed that it sank, demonstrating its remarkable resilience.
The RMIT team also tested a 3D-printed marine buoy, which maintained stability in a turbulent seawater tank, remaining buoyant without the need for an outer sealing or protective coating.
Looking ahead, project leader Distinguished Professor Ma Qian emphasized the potential for scaling this technology for real-world applications. The team hopes to investigate the material’s performance under various marine conditions and explore its use in different sectors.
“By altering the material within the titanium framework, we could adapt this structure for uses in energy absorption, thermal management, vibration control, and more,” Professor Qian said.
This project was conducted in collaboration with the Conservatoire National des Arts et Métiers in France, receiving support from the Australian Research Council and RMIT’s School of Engineering. The findings, titled “Breaking the surface: buoyant metal–polymer open–cell hybrid lattice metamaterials,” were published in the journal Advanced Materials.
With such innovations on the horizon, the future of marine infrastructure looks promising.
