Monash University team makes a leap forward in aerospace, defence, energy, and space manufacturing.

Engineers at Monash University, in a world-first study, have demonstrated how cutting-edge 3D printing can now produce ultra-strong commercial-grade titanium alloy. This had also been reported in an earlier article on 3D printing Titanium Alloys. This is a real leap forward for the aerospace, defence, energy, space, and biomedical industries.

Researchers from Australia, led by Professor Aijun Huang, and Dr Yuman Zhu both of Monash University, manipulated a novel microstructure, through a 3D-printing method. The result is that achieved unprecedented mechanical performance.

Commercially available alloys

One of the major benefits of this research is the work was undertaken on commercially available alloys and can be utilised immediately. This is a wide-ranging positive outcome. 

“Titanium alloys require complex casting and thermochemical processing to achieve the high strengths required for some critical applications,” said Dr Huang in a statement.

“We have discovered that additive manufacturing can exploit its unique manufacturing process to create ultra-strong and thermally stable parts in commercial titanium alloys, which can be directly implemented in service.” 

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

Over the past 10 years, 3D printing has led to a new era in metal fabrication due to its design freedom. That is being able to fabricate just about any geometrical part. Presently, titanium alloys are the leading 3D-printed metal being used for components in the aerospace industry.

Unfortunately, most commercially available titanium alloys created by 3D printing do not have the properties for structural applications. This is especially true for the tensile strength at room temperature and elevated temperatures in harsh service environments. 

The main properties of the titanium alloy are attributed to the unusual formation of dense, stable, and internally twinned nanoprecipitates, which are rarely seen in traditionally processed titanium alloys. The technique used here is Additive Manufacturing (AM).

Much stronger than aluminium alloys

AM is an enabling technology providing design freedom as not seen before, in this type of 3D creation of titanium alloys. Titanium, in general, is much stronger than aluminium alloys, and lighter than steel, with makes them more energy efficient.

The buy-to-fly ratio, the ratio of starting to final weight, is closer to 1:1 rather than the 10:1 to 40:1 that can be realised when using convention manufacturing techniques.

The use of and number of AM titanium products currently used in industry is still limited, when compared to conventionally produced titanium components. The reason for this is that major issues in the AM products that are produced today are simply not structurally strong enough. The microstructures that make up the form of a titanium component had not be fully understood.

The work done at Monash have produced a more fundamental understanding of the densities, segregation of elements and unique solidification structures. This then opened the door to the nanotwinned precipitates properties of higher densities and tensile strengths, in a ratio that was close to 1:1.

The applications can begin immediately, which is rare for a study or research project. This technique can be used in many industries including automotive parts and structures.

The full study was published in Nature Materials