Researchers at Tohoku University in Japan have made a major breakthrough in 3D printing technology, creating a new way to produce lightweight but strong car parts.
Their findings, published in Additive Manufacturing on November 19, 2024, could change how cars are built, making them more efficient and environmentally friendly.
Metal 3D printing works by layering materials to build an object.
Heat is used to bond the layers, creating precise shapes with minimal waste. This process allows for highly customized designs that are hard to achieve with traditional manufacturing.
Using 3D printing to combine different materials, such as steel and aluminum, opens up exciting possibilities. For example, steel car parts can be made lighter by mixing in aluminum without losing strength. These “multi-material” structures combine the best qualities of each material, but they come with challenges.
One big problem with mixing steel and aluminum is that they don’t bond well naturally. When these metals are joined, brittle intermetallic compounds often form at the connection points, making the material weaker.
“Multi-materials are a hot topic because of their flexibility in design,” says Associate Professor Kenta Yamanaka of Tohoku University. “But the brittle compounds at the metal interfaces are a serious challenge for practical use.”
To solve this problem, the research team used a method called Laser Powder Bed Fusion (L-PBF).
This technology melts metal powders with a laser to create solid structures. By increasing the speed of the laser during the process, they discovered they could reduce the formation of weak points between the two metals.
This is because faster printing leads to something called “non-equilibrium solidification,” which prevents the materials from separating into brittle compounds.
The team successfully created a prototype suspension tower, a key car part, using this method. It’s the first full-scale automotive component made with this multi-material 3D printing technique. The new part is both lightweight and strong, meeting the high demands of car manufacturing.
Specially Appointed Assistant Professor Seungkyun Yim explains, “You can’t just stick two metals together and expect them to work. We had to fully understand how they bond at the molecular level.”
The researchers plan to expand their work to other metal combinations. This advancement could lead to stronger, lighter, and more efficient designs not only in cars but also in airplanes, machinery, and more.
This innovation marks a significant step toward greener manufacturing and smarter use of materials in industries worldwide.
Source: Tohoku University.
