Nature is the greatest teacher for engineers. Humans have developed surgical needles from mosquitoes, LED lights from fireflies, and even helicopter technology from hummingbirds.
To create some of the toughest aerospace materials, engineers have drawn inspiration from the crystalline structures found in the giant water lily (Victoria amazonica) and tube coral (Tubipora musica).
Underside of the giant water lily (Victoria amazonica).
However, observing a super-strong natural structure is one thing; reproducing it with artificial materials is another. For decades, researchers have attempted to create “cellular structures” resembling those found in nature, but their efforts have often failed due to manufacturing challenges.
Fortunately, the current era of 3D printing offers a level of sophistication that allows engineers to explore the lightweight yet durable secrets of nature.
Super Titanium Material: A New Weapon Against Wear and Tear
In a recent paper published in the journal Advanced Materials, scientists from the Royal Melbourne Institute of Technology (RMIT) in Melbourne, Australia, have developed a 3D-printed super material that is 50% stronger than the cast magnesium alloy WE54 with a similar density used in the aerospace industry.
The new super material is made from a common titanium alloy. What sets it apart is its structure. This material features a naturally-inspired lattice design (similar to those in the giant water lily and tube coral) that not only makes it unique but also incredibly sturdy.
Super titanium material stronger than aerospace-grade magnesium alloy WE54. (Image: RMIT).
According to the research team’s findings, this material is 50% more durable than the next strongest alloy with similar density used in aerospace applications.
The research team overcame a common issue with these “cellular structures”, where stress (tension) concentrates in specific areas of the supporting beam, leading to premature failure. Instead, the scientists designed a network of interconnected structures that evenly distribute load stress to avoid “hot spots” while redirecting cracks along the structure.
Ma Qian, a renowned professor at RMIT and co-author of the study, stated in a press release: We have designed a hollow tubular lattice structure with a thin strip running inside. These two factors together exhibit strength and lightness never seen in nature.
The creation of this ultra-durable multi-structured lattice network was made possible by RMIT’s laser powder bed fusion (L-PBF) machine, which is far more complex than your typical desktop 3D printer.
True to its name, this machine uses metal powder that is melted in place by a high-powered laser beam. The result is a titanium lattice (50% stronger than the WE54 cast magnesium alloy).
This remarkable level of manufacturing freedom allows researchers not only to create extremely durable lattice blocks but also to produce them in various sizes – from several meters to just a few millimeters, expanding their potential applications across different industries.
“Compared to the strongest available cast magnesium alloys – currently used in commercial applications requiring high strength and lightweight – our titanium super material with equivalent density has shown to be significantly stronger or less likely to undergo permanent deformation under compressive loads, not to mention much more feasible to produce,” explained lead author Jordan Noronha.
The authors also noted that this material has exceptional corrosion resistance and heat resistance, capable of withstanding temperatures up to 350 degrees Celsius and even 600 degrees Celsius, the scientists believe. This will make it an excellent material for aerospace engineering, firefighter drones, and automotive manufacturing.
While the discovery of this extremely strong super material is a crucial first step, producing such a complex object at scale presents another challenge. This is primarily because not everyone has access to a laser powder bed fusion (L-PBF) printer.
But once they achieve this, the wonders of nature will once again be within our reach.
