To propel the development of 3D printing, CQU research team made a new success. On February 27, it was learned from CQU that the joint research team of CQU College of Materials Science and Engineering, the University of Queensland, Australia, and the Technical University of Denmark published a paper titled "Ultrauniform, strong, and ductile 3D-printed titanium alloy through bifunctional alloy design" in Science. According to the paper, a bifunctional alloy design strategy was proposed, which breaks new ground in exploring a variety of raw materials of metal powders, variable printing alloy systems, different 3D-printing technologies, and advanced multi-material printing.

In recent years, 3D printing has emerged frequently as a new technology. The metal 3D printing process usually involves multiple physical and metallurgical phenomena, rendering the printed components with complex microstructures and diverse mechanical properties. "During the 3D printing process, metals often form coarse columnar grains and unevenly distributed phases, and such a microstructure not only leads to non-uniformity in the mechanical properties of the printed components, but also diminishes the mechanical properties of the components." When it comes to the original intention of this research, Prof. Huang Xiaoxu of CQU College of Materials Science and Engineering indicated that the original idea of this collaborative research was to work on a bifunctional alloy design, so as to obtain superior and uniform titanium alloys directly through 3D printing.

Titanium alloy is one of the most widely used metal 3D printed materials today, according to Prof. Huang. In engineering applications at room temperature, suitable titanium alloys typically exhibit a tensile elongation of 10-25%, which reflects well-established material reliability. However, there has always been a need to balance strength and ductility in both traditional and additive manufacturing techniques for processing metallic materials.

Effective regulation of microstructure in the bifunctional alloy design strategy enabled the researchers to successfully print a high-strength, high-ductility and uniform titanium alloy with a yield strength of 926 MPa and an elongation at break of 26%. This translates into an optimal balance between strength and ductility.

The strategy is expected to be applied to the 3D printing of other powder mixtures and to enable the customization of varying alloys with enhanced properties, according to a concurrent review in Science. The strategy also addresses the conflict of balancing strength and ductility in the printed state and minimizes the need for post-printing treatment, making it a new research sensation in the field of 3D printing, according to industry insiders.