Monash University researchers discover durable microstructure makes stronger titanium

A world-first study led by Monash University engineers in Australia has demonstrated how cutting-edge 3D printing techniques can be used to produce ultra-strong titanium alloy – a significant leap forward for the aerospace, space, defense, and biomedical industries.

"Titanium alloys require complex casting and thermomechanical processing to achieve the high strengths required for some critical applications," said research lead Professor Aijun Huang. "We have discovered that additive manufacturing can exploit its unique manufacturing process to create ultrastrong and thermally stable parts in commercial titanium alloys, which may be directly implemented in service."

Led by Huang and Yuman Zhu from Monash University, the Australian researchers used a metal 3D printing method to manipulate a novel microstructure. In doing so, they achieved unprecedented mechanical performance.

"After a simple post-heat treatment on a commercial titanium alloy, adequate elongation and tensile strengths over 1,600 MPa (megapascals) are achieved, the highest specific strength among all 3D printed metal to date," continued Huang. "This work paves the way to fabricate structural materials with unique microstructures and excellent properties for broad applications."

Titanium alloys are presently the leading metal in 3D printed metal components for the aerospace industry. However, most commercially available titanium alloys made with 3D printers do not have satisfactory properties for many structural applications, especially their inadequate strength at room and elevated temperatures under harsh service conditions.

"Our findings offer a completely new approach to precipitation strengthening in commercial alloys that can be utilised to produce real components with complex shapes for load-bearing applications," added Huang. "This application is still absent for any titanium alloys to date."

The findings were published in "Nature Materials" and are expected to lead to fundamental insights into the principles of strengthening and dislocation engineering in the field of physical metallurgy.

Additionally, the research was done on commercially available alloys and can be applied immediately.