A look at AM materials: Advantages, challenges, and trends

In this article, our AM materials specialist, Karl Frederik F?rch Fischer , who works in the Danish Technological Institute's department for AM research and development, will look at which materials are trending in 3D printing - and what advantages companies can gain by adopting a new material for 3D printing.

3D printers have long been capable of printing with polymers and metals, and over time, the quality and speed of printing parts have improved significantly. However, metal printing comes with its own set of challenges. For instance, it requires more powerful and therefore more expensive lasers, consideration of heat conduction, stress, and other factors, which is why metal printing is still not as widespread in the industry.

With a proper understanding of the process, it is absolutely possible to print in metal—even on a commercial scale. Of course, cost is also a barrier for some, and this largely depends on print time. Optimizing print time requires fine-tuning the printer's laser settings to strike the perfect balance between speed and defect-free printing.

This is exactly what I focus on in my daily work. For example, I am investigating how to print more quickly in the steel type 316L. This stainless steel has been used for 3D printing for some time, and we have produced many components for customers using it.

In collaboration with the printer supplier Nikon SLM Solutions , I have worked on developing high-productivity parameters for this steel type to make it significantly more advantageous for printing.

Specifically, I have been defining our parameter space for the tests we want to conduct on the printer. I do this by identifying an area with good settings for the printer and then casting a "net" around that point. Afterward, I program the printer to perform a series of tests, allowing me to evaluate where the welding and melting processes work best. Essentially, it’s about achieving high density in the parts, which is determined by the amount of air pockets and tensile strength.

In addition to optimizing the print speed and quality of already known materials, it’s also worthwhile to explore the possibilities of printing with entirely new materials. This can be driven by the materials' unique properties, such as strength, thermal conductivity, weight, and temperature tolerance.

Copper—specifically CuCr1Zr—is a great example of a material suited for 3D printing due to its unique properties in both thermal and electrical conductivity. Copper can be used, for instance, in heat exchangers that efficiently transfer heat between two fluids. The material is also valuable for creating specialized electrical conductors and contacts or improving heat transfer for more effective cooling. While the printing process can be quite expensive, the design freedom often allows for much better heat transfer or electrical conduction, making it cost-effective in the long run.

Heatflow ApS is a Danish company that develops solutions within thermal systems. As part of the design optimization project DfAM Green (Design for Additive Manufacturing), which was initiated by Danish AM Hub , they have developed an optimized evaporator for server cooling. The evaporator is 3D-printed in a copper alloy, which helps improve server cooling and enables more efficient heat reuse.

Copper is an excellent choice when it comes to cooling servers. Recently, the Danish Technological Institute submitted a major research proposal aiming to explore how 3D printing in a copper alloy can be used to develop server cooling solutions for large data centers. The significant interest in this area stems from the potential to reduce energy consumption, minimize waste heat, and cut down on the amount of power lost as heat.

The electrical conductivity of CuCr1Zr is also very high, making it an excellent material for transmitting electricity. The alloy can be heat-treated to achieve a conductivity that is 90% of pure copper's conductivity. This makes it particularly useful for producing contacts and complex electrical installations.

There is already a high demand for copper alloys and the ability to 3D print in copper. This is why, at the Danish Technological Institute, we have started developing the capability to print CuCr1Zr in even thicker layers in collaboration with Nikon SLM Solutions. The goal is to enable faster and more cost-effective printing with the alloy. It is already possible to print in 30 μm and 60 μm layers, but now we are working on developing parameters to print in 90 μm layers, which will significantly speed up the printing process.

A lot is happening in the development of materials for 3D printing, which continuously creates new opportunities to test the properties of new materials or further develop existing ones.

For instance, another interesting material for AM is the aluminum-zirconium-iron alloy Aheadd CP1 - you can read more about here

It would be exciting to hear what potential you see in the new materials for 3D printing. And just as importantly, what properties you would like to see in the materials of the future for 3D printing. Feel free to comment.