The NRC road-tests new multiscale approach to simulate metal 3D printing

Every year, millions of metal parts are manufactured for vehicles, trains, planes and ships. Each part undergoes a lengthy and costly process of research, design, prototyping and testing before reaching production—all under pressure to deliver higher-quality products faster and at lower cost.

One technology revolutionizing how metal parts are made is additive manufacturing, also known as 3D printing or rapid prototyping. Additive manufacturing enables the production of parts with complex geometries that can't be made using conventional manufacturing methods. It also enables the production of automotive parts that are both strong and lightweight and offers the potential to lower production costs, extend part lifespan and reduce the environmental impact of manufacturing.

However, there are still challenges to industry adoption. These new processes must eliminate the need for costly trial-and-error approaches, make parts more cost-effective to produce, support flexible production schedules (whether on-demand or at scale) and shorten time to market for new parts. To meet these goals, manufacturers need the ability to predict and resolve production problems in advance—which is where numerical simulation comes in.

The modelling and simulation research team at the NRC's Automotive and Surface Transportation Research Centre is a leader in the modelling, simulation and optimization of industrial processes. Lately, the team has focused on solving key challenges in laser powder bed fusion (LPBF), one of the most widely used metal 3D printing methods.

In LPBF, a laser beam to melt a thin layer of metal powder spread across a platform. This process is repeated layer by layer, fusing the material together until the final part is formed. Although LPBF is a powerful manufacturing process, its broader adoption still faces barriers—particularly build failure during fabrication and difficulties meeting design specifications and tolerances.

"To solve these problems, we've developed a fast and accurate numerical simulation method for LPBF that predicts where flaws might occur," says Dr. Yohann Vautrin, a research officer at our research centre's facility in Boucherville, Quebec. "Our advanced simulation software can predict how metal parts behave during and after printing."

With simulation, companies can adjust the design or tweak the printing parameters all without doing any printing at all! This can translate into tremendous savings of time, materials and money.

"We hope this will accelerate the adoption of metal additive manufacturing in Canada," adds Yohann. He also highlights that companies partnering with the NRC through its METALTec industrial R&D group have access not only to confidential R&D results, but also to the research team itself, which can carry out specific studies for them upon request.

Like most NRC initiatives, the success of this multiscale LPBF simulation project is rooted in strong collaboration with industrial and academic partners. Developed jointly by the NRC and research teams from Polytechnique Montréal, Concordia University and McGill University, the project brought together complementary expertise to build numerical simulation models at different time and length scales.

The multiscale approach allows full-part simulations of the LPBF process to be completed in a matter of minutes rather than days or weeks by strategically trading some accuracy for speed. It starts with a microscale model (around 100 micrometres), which offers a highly accurate physical representation but requires substantial computational resources. Then a mesoscale model (around 1 millimetre) uses this data to simulate how the laser moves across the powder in a simplified way. Finally, a part-scale model combines this information to quickly simulate the printing of an entire industrial part.

Starting from scratch, the team has shown that this multiscale approach could tackle real world manufacturing problems. While more work is needed to turn it into ready-to-use tools, the results are promising.

In the future, this approach could lead to even smarter features like automated design optimization, geometry compensation for near-net-shape printing and integration with digital twins and real-time monitoring systems – all to make metal 3D printing more reliable and efficient.

The project received $1.14 million in funding from members of the METALTec industrial R&D group, CRITM (in French only), a Quebec research and innovation consortium in metal processing financed by the provincial government, and the NRC's Advanced Manufacturing Cluster Support Program (through the Collaborative Science, Technology and Innovation program, administered by the NRC's National Program Office). The project also supported the training of more than 8 highly qualified personnel allowing the research team to further strengthen its capabilities.

With unique, well-established and emerging research capabilities and a strong focus on innovation, the NRC represents both a reliable partner for manufacturers and a training ground for highly skilled individuals. The NRC, by supporting collaboration, advancing the development of simulation tools and sharing research with industry and academia through initiatives like METALTec, is helping to lay the foundation for broader adoption of additive manufacturing technologies in Canada. As metal additive manufacturing technologies continue to mature, their integration into mainstream production will play a critical role in shaping the future of transportation.