On January 3, 2025, the resource library learned that the research team of the Institute of Materials Science and New Industry Creation Incubation Center of Tohoku University in Japan achieved a major breakthrough through to multi-material metallic PBF (laser fusion on powder bed). ) technology and successfully developed aluminum The 3D printing process of steel composite materials opens new possibilities for the application of multimetallic materials in 3D printed frames.
Innovative breakthrough in multi-material metal PBF technology
Metal 3D printing, especially laser powder bed fusion (L-PBF) technology, has been widely used in the manufacturing of high-precision and high-complexity parts. Compared with traditional manufacturing processes, L-PBF can precisely control part geometry by melting metal powder layer by layer and improve part performance by optimizing material distribution. In this technology, material selection and structural design are particularly critical, and multi-material printing can overcome the limitations of a single material and maximize functionality and performance.
Using this technology, the Northeastern University research team managed to combine different materials such as aluminum and steel, and solve the interface problem between metals. Traditionally, due to differences in thermal expansion coefficients and physical properties between aluminum and steel, brittle intermetallic compounds are easily formed at joints, thereby affecting structural strength.
To solve this problem, the research team used a method calledLaser Powder Bed Fusion (L-PBF)process, which is one of the leading technologies in the field of metal 3D printing. This method uses the laser to selectively melt metal powder layer by layer. Through experiments, the team found that by increasing the laser scanning speed, they could significantly suppress phenomena such as.Al5Fe2AndAl13Fe4Formation of isofragile compounds.
The researchers further determined that this higher scanning speed triggers a process callednon-equilibrium solidificationphenomenon, thus reducing the distribution of solutes and preventing the formation of weak points in the material. Ultimately, this steel-aluminum alloy features a strong bonding interface and successfully achieves both lightness and durability.
Lightweight advantages of aluminum-steel composite materials
Aluminum and steel each have their own advantages. Aluminum is a lightweight metal widely used in automobile manufacturing. Its good strength/weight ratio, excellent corrosion resistance and ease of processing make it an ideal choice for lightening automobiles. However, aluminum has relatively low strength and cannot meet some structural load-bearing requirements. On the other hand, steel is stronger and suitable for parts that can withstand greater stresses, but its density increases the weight of the car.
Thanks to multi-material PBF technology, the advantages of aluminum and steel are complemented. In the process of manufacturing automobile parts, the research team combines aluminum and steel precisely according to functional requirements: aluminum is used for lightweight parts of the body and frame, while steel is used for parts that require higher strength. This move not only significantly reduces the weight of the entire vehicle, but also ensures the safety and durability of the chassis and body. Particularly in crash protection design, the high strength of steel ensures the structural integrity of the vehicle, while the lightweight properties of aluminum help reduce overall vehicle weight and improve fuel efficiency .
Specific applications: lightness and structural optimization
Using multi-material 3D printing technology, the combination of aluminum and steel can not only make the frame lighter, but also achieve structural optimization according to the needs of different areas. For example, in non-load-bearing parts of the frame, the use of aluminum materials can effectively reduce weight, while in parts carrying greater load or force, steel can be used to ensure sufficient strength. Using 3D printing, manufacturers can precisely select material combinations based on the specific needs of each component, further improving the performance of the overall structure.
Practical application of a technological breakthrough: 3D printing of large-scale automotive suspension towers
Using this technology, the research team managed to createThe world’s first full-scale automotive suspension tower prototypeThis component features a custom geometric design that fully demonstrates the potential of aluminum-steel composites in real-world automotive parts. As an important part of the automobile structure, the suspension tower must have sufficient strength and toughness to cope with various impacts and stresses on the road.
Technical challenges and future prospects
Although this technology has made great progress, by increasing the laser scanning speed, the research team successfully removed the problem of joint surface brittleness, but in larger-scale industrial production, how to further optimize this process to ensure the perfect combination of materials There are still problems. This is a key question that must be resolved in the future.
In the future, the researchers aim to apply their method to other metal combinations facing similar bonding issues, potentially opening up a wider range of applications in various industries. This not only provides a more efficient production model for the automobile industry, but also can promote the development of other fields (such as aviation, aerospace, machinery manufacturing, etc.) toward better design and multi-material production.
