International Team Creates New Titanium Alloy With 3D Printing TechnologyInternational Team Create New Titanium Alloy With 3D Printing Technology

An international team of researchers, including RMIT University in Australia and the University of Sydney, have combined alloys and 3D printing processes to create a new titanium alloy that is strong but not brittle under tension. The breakthrough, published in the latest issue of the journal Nature, holds promise for the development of a new class of more sustainable high-performance titanium alloys for applications in aerospace, biomedicine, chemical engineering, space and energy technology .

The new titanium alloy consists of a mixture of two titanium crystals, called the alpha-titanium phase and the beta-titanium phase, each corresponding to a specific arrangement of atoms. Oxygen and iron are the two most powerful stabilizers and strengtheners for the α-titanium and β-titanium phases, and they are abundant and cheap.

But the researchers found that two challenges have hindered the development of tough alpha-beta ferro-titanium alloys through conventional fabrication processes. One challenge is that oxygen can embrittle titanium; another is that the addition of iron can lead to severe metallurgical defects, forming bulk β-titanium.

The team printed their alloy from metal powder using laser directed energy deposition, a 3D printing process suitable for making large, complex parts. They combined the alloy design concept with the 3D printing process design, and determined a series of alloys that are strong, ductile, and easy to print.

The key enabling factor is the unique distribution of oxygen and iron atoms within and between the α-titanium and β-titanium phases. The researchers engineered a nanoscale oxygen gradient in the alpha-titanium phase with robust high-oxygen segments and ductile low-oxygen segments, enabling control over local atomic bonds and reducing potential embrittlement.

The team says the tantalizing properties of these new alloys are comparable to commercial alloys.

Professor Simon Linge, vice-chancellor of the University of Sydney, said the study provided a new titanium alloy system with a wide range of tunable mechanical properties, high manufacturability, huge potential for emission reduction, and the first of its kind. Material Design provides insights.

The team's design, which incorporates circular economy ideas, holds promise for producing new titanium alloys from industrial waste and low-grade materials, the researchers said. 

Furthermore, oxygen embrittlement is a major metallurgical challenge not only for titanium but also for other important metals such as zirconium, niobium, molybdenum and their alloys. The new research may provide a template for mitigating these oxygen embrittlement issues through 3D printing and microstructural design.