Functional Design with 3D Printers
For some time now, the news has been buzzing with talk of 3D printers making manufacturing more accessible. In fact, 3D printers are not entirely new, as they have been used since the 1980s under the name of rapid prototyping. However, since former President Obama declared an industrial revolution in the United States centered on 3D printers in the 2010s, when key patents expired, the global development race has intensified.
When you think of 3D printers, you might imagine a device that can easily create figurines and small craft items from plastic, but their development has been rapid, and their industrial applications are expanding significantly. From metals and ceramics to food and biomaterials, surprising practical applications continue to be reported one after another around the world. As a technology that provides unique and optimal products for everyone, 3D printers will dramatically improve the quality of life in the future.
In this development process, it is essential to consider appropriate methods for handling each material. For example, while there are many metal products around us, metals—which can have melting points of 1000°C or higher and greater strength compared to plastics—are extremely difficult to handle in 3D printing. One of the additive manufacturing methods capable of handling metals is Directed Energy Deposition (DED), which supplies metal powder while melting a base metal using a high-power laser or similar energy source. Due to its high deposition efficiency and ability to create complex shapes, DED is beginning to be applied in the production of aircraft and automotive parts. Another appeal of 3D printers is the advantage of being able to easily use materials that are difficult to process with conventional techniques, such as nickel-based alloys and titanium alloys, which are in high demand in these industries.
In our laboratory, in addition to these known benefits, we aim to elevate DED into an even more versatile technology. For example, by mixing and depositing multiple metal powders while varying their composition ratios, it is possible to create dissimilar material joints without a distinct interface, known as graded alloys. We are exploring the potential of DED as a technology that allows for the free design of functionalities, such as mitigating stress concentration at joints or altering the mechanical properties of only a part of a component. Furthermore, we have proposed a simple fabrication method for a functional material with a porous structure, known as porous metal, by mixing a foaming agent with metal powder. Porous metals have been recognized for their diverse functionalities—including being lightweight, having high specific stiffness, vibration and shock absorption, sound insulation, and electromagnetic shielding—but they were difficult to produce with conventional techniques. If freeform shapes can be easily created with porous metals, it would be possible to dramatically improve all sorts of performance aspects of everyday metal products.
As you can see, 3D printers still have much room for growth. The future is near where 3D printers will merge with conventional processing technologies to continuously create new added value.