New multi-material metal 3D printing technology for lightweight and durable automotive parts

Lightweighting, or the concept that lighter cars can improve fuel efficiency, battery life, acceleration, braking and handling, is one of the biggest trends in automotive technology today. automobile manufacturing. But challenges remain, particularly when it comes to combining materials to take advantage of their different properties, such as the strength of steel and the lightness of aluminum. Researchers at Tohoku University’s Materials Institute and New Industry Incubation Center work on new multi-material metalsA major breakthrough has been made in 3D printing technology, which can be used to create lightweight and durable automotive parts.

Additive manufacturing is becoming very popular in the automotive industry. In a press release from Northeastern University, it was highlightedThe precision of 3D printing as a method of producing unique and highly customizable shapes. However, the materials used often have drawbacks, hence the interest in multi-material 3D printing. But this is not absolutely true.

Interface strength of steel and aluminum alloy melted multi-materials at different scanning speeds using laser melting (Photo source:Kenta Yamanaka, etc.)

“Multimaterials are a hot topic in additive manufacturing due to the flexibility of the process,” explains Associate Professor Kenta Yamanaka. However, a major challenge in practical implementation is that for certain combinations of metals, such as steel and aluminum, brittle intermetallic compounds can form at the interface of different metals. So even though the material is now lighter, it ends up being more fragile.

The research team specifically targeted laser powder bed fusion, one of the leading computer-aided manufacturing processes in the automotive sector, seeking to produce a steel and aluminum alloy that is both lightweight and sustainable. They found that increasing the scanning speed of the laser could significantly suppress the formation of fragile intermetallic compounds (CitationExamples of Al5Fe2 and Al13Fe4).

to useLPBF bonding results of a steel-aluminum alloy at different scanning speeds (Photo credit: Kenta Yamanaka et al.)

The researchers believe this is due to so-called unbalanced solidification, which minimizes the distribution that could lead to weak points in the material. This is how they are able to demonstrate a strong interface. one of the team membersSeungkyun Yim clarified, “In other words, you can’t just stick two metals together and expect them to stick together without a plan. We must first fully understand the in situ alloying mechanism.。