ADVANCED MATERIALS & PROCESSES | OCTOBER 2025 68 3D PRINTSHOP STRONGER, MORE DUCTILE TITANIUM ALLOY By using alternative materials to replace the commonly used vanadium in titanium alloys, a team from RMIT University has developed a stronger, cheaper titanium built for 3D printing. “3D printing allows faster, less wasteful, and more tailorable production, yet we’re still relying on legacy alloys like Ti-6Al-4V that don’t allow full capitalization of this potential. It’s like we’ve created an airplane and are still just driving it around the streets,” says Ryan Brooke, Ph.D. candidate at RMIT and lead author of a recent publication about the material. The group’s study, published in Nature Communications, outlines a time- and cost-saving method to select elements for alloying, taking advantage of emerging 3D-printing technology. This work provides a clearer framework for predicting the printed grain structure of metallic alloys in additive manufacturing. It has already been used to achieve impressive results: The team’s alloy is 29% cheaper to produce than standard titanium. Through this design framework, the metal also prints more evenly, avoiding the column- shaped microstructures that lead to uneven mechanical properties in some 3D-printed alloys. “By developing a more cost-effective formula that avoids this columnar microstructure, we have solved two key challenges preventing widespread adoption of 3D printing,” he adds. rmit.edu.au. LATTICE STRUCTURE REPLICATES MUSCULAR ORGANS Inspired by biology, a team from the Computational Robot Design and Fabrication Lab (CREATE) in EPFL’s School of Engineering has created a scalable way to design light- weight, adaptable robots. The lattice, made of a simple foam material, is composed of individual units (cells) that can be programmed to have different shapes and positions. These cells can take on over one million different configurations and even be combined to yield infinite geometric variations. The team’s programmable lattice can be printed using two main cell types with different geometries: the body-centered cubic (BCC) cell and the X-cube. When each cell type is used to 3D print a robotic “tissue,” the resulting lattice has different stiffness, deformation, and load- bearing properties. But the CREATE Lab’s method also allows them to print lattices made of hybrid cells whose shape lies anywhere on the spectrum between BCC and X-cube. “This approach enables the continuous spatial blending of stiffness profiles and allows for an infinite range of blended unit cells. It’s particularly suited for replicating the structure of muscular organs like an elephant trunk,” says Ph.D. student Benhui Dai. In addition to modulating each cell’s shape, scientists can also program their position within the lattice. This second programming dimension allows them to rotate and shift (translate) each cell along its axis. The cells can even be superimposed onto each other to create entirely new cell combi- nations, giving the resulting lattice an even wider range of mechanical properties. To give an idea of the sheer scale of potential variations, a lattice cube with four superimposed cells can yield around 4 million possible configurations, with over 75 million configurations for five cells. epfl.ch/en. Ryan Brooke inspects a sample of the new titanium produced by the RMIT team. Courtesy of RMIT University. Concept of a lattice musculoskeletal robot. Courtesy of Science Advances, doi.org/10.1126/ sciadv.adu9856.
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