Ellen Phiddian
Cosmos science journalist
An international team of researchers has figured out that a super-strong titanium alloy, a key material in a number of industries, can be 3D-printed.
Because of its extreme strength compared to its weight, titanium alloys are used all over the aerospace, automotive, defence, biomedical and energy sectors.
But they’re tricky to make, needing elaborate casting and thermomechanical processing to get their strength.
Until now.
A paper published in Nature Materials has outlined an additive manufacturing (3D-printing) process for making a commercial titanium alloy.
“Using a new process on an existing material is always interesting for industry, because you can use it straightaway,” says senior author Professor Aijun Huang, a researcher in materials science and engineering at Monash University.
“People always have concerns that a 3D-printed alloy will not be as good as a lot of forged alloys, or sometimes even not as good as cast alloys.
“So trying to find a new way to improve the mechanical performance is always a hot point for the 3D-printing area.”
Huang describes the new technique for making the “nano-twinned” alloy as “very simple”.
Titanium powder, with micrometre-sized particles, is fired into a shape using a 3D-printing technique called laser-powder bed fusion.
Then, the printed material is heat-treated at 480°C.
The resulting material has an ultimate tensile strength of over 1600 megapascals – making it the strongest known 3D-printed metal. (For comparison, some of the strongest non-3D printed titanium alloys are around 2000 megapascals.)
More on titanium alloys and additive manufacturing: 3D printing rocket and satellite parts
Huang says that the new process could be used by industry straightaway, “especially for the aerospace, space and defence industry”.
“A lot of people are interested in trying to design new materials by 3D printing, which is always interesting,” says Huang.
“But in the industry, they don’t like new materials. The approval process for new materials is very tedious, very expensive.
“We worked on a commercial alloy, which is available already.”