Materials

New titanium alloy has highest specific strength of any 3D-printed metal

The new titanium alloy being 3D printed through a laser powder bed fusion technique
Monash University
The new titanium alloy being 3D printed through a laser powder bed fusion technique
Monash University

Engineers at Monash University have developed a new 3D-printable titanium alloy with a unique microstructure that makes it ultra-strong. Not only is it stronger than most other forms of titanium, but it has the highest strength-to-weight ratio of any 3D-printed metal ever made.

Titanium alloys are already prized in industry thanks to their strength and relatively light weight, which makes them perfect for aircraft and other vehicles. But there’s always room for improvement, and the new Monash alloy not only boasts greater strength, but because it’s 3D printed, it’s much easier to make into whatever shape is needed.

The team starts with a common 3D printing technique where a bed of powdered metal is melted by a laser, fusing it into a solid layer by layer. In this case, that powdered metal is the commonly used beta-titanium alloy. Next, the material undergoes heat treatment at temperatures between 480 and 520 °C (896 and 968 °F), which produces a microstructure that gives the alloy its incredible strength.

The treatment process causes particles of titanium to precipitate together in nanograins, which merge in “nanotwin” structures that each share a common side. The team says this is the first titanium alloy to exhibit this kind of structure, and it makes it much stronger than usual.

In tests, the team demonstrated that the new titanium alloy had both elongation and tensile strengths (stretching and tension, respectively) of over 1,600 MPa. For reference, most commercial titanium alloys top out at around 1,000 MPa. This is also the highest specific strength for any other 3D-printed metal alloy, the team says.

“Our findings offer a completely new approach to precipitation strengthening in commercial alloys that can be utilized to produce real components with complex shape for load-bearing application,” said Professor Aijun Huang, lead researcher on the study. “This application is still absent for any titanium alloys to date. The 3D printing plus simple heat treatment also means the process cost is greatly reduced compared to other materials with similar strength.”

The research was published in the journal Nature Materials.

Source: Monash University

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6 comments
clay
So it's just heat treated Titanium? That does not appear to be all that new. It appears the magic is in the heat treat process.

I wonder if this precipitation process can work with other metals, like steel or stainless steel?
Kpar
Good points, lay. What about the other characteristics of this metal alloy? Brittleness, durablility, temperature resistance?
Brian
This is very cool!
josefaber
.
3D printing will give a nearly finished product, fewer steps needed.
Fusion bed sintering followed by tempering at half the usual forging temperature
gives a strength of 1600MPa(232,060.4psi) v. 1000MPa(145,038psi) with conventional process.
Treon Verdery
Laser Shockwave peening is a technology published as causing 15 times greater durability, and similar amounts of fracture resistance. This could be applied to the new nanotwinning titanium crystal 3D printing process as well.
Expanded Viewpoint
No, Clay, it's not just some heat treated Titanium. It's an ALLOY of Titanium, just like it says in the article. To alloy something means to mix two or more things together, and getting something different from doing so. Some of the alloying metals used with Titanium are Vanadium, Iron, Molybdenum. By varying the elements and their ratios, you can get a wide range of altered properties, both good and bad.