All You Need to Know About Copper 3D Printing

Known for its reddish-orange hue, copper is a popular metal due to its exceptional physical properties. These characteristics have made it a key material in a variety of industries, from electronics to the creation of end-use parts. With advances in 3D printing, copper has found a new field of application, enabling the creation of complex, customized designs that were previously difficult to realize. To better understand the properties of this metal, the benefits it brings to 3D printed parts and the leading manufacturers on the market, read this guide.

Characteristics of the Material

Copper (Cu), atomic number 29, is a chemical element. It is the third most widely used metal in the world, after iron and aluminum, and an increasingly popular option in additive manufacturing. Copper’s popularity stems from its interesting properties, particularly its conductivity. Thanks to its good electrical conductivity, ductility and malleability, it is one of the most widely used metals for the manufacture of electrical components.

If we focus on its use in 3D printing, we find various copper-based alloys, but with slight variations between them. Below we list some of the most common alloys and their specific characteristics:

• Cu (pure copper): excellent electrical and thermal conductivity, used in electrical components;
• CuCrZr (copper-chromium-zirconium): improves resistance to deformation and hardness;
• CuCP (phosphorized copper): corrosion-resistant and ductile;
• CuSn (tin-plated copper): improves corrosion resistance and hardness;
• CuNi30 (copper-nickel 30): offers improved corrosion resistance and mechanical properties.

Copper powder (photo credits: Inoxia)

The extraction of this material begins in mines (open-pit or underground), where copper ore is extracted from the earth. Once extracted, the ore is crushed and ground to reduce it to smaller particles, facilitating the liberation of copper from other minerals. Subsequently, a series of processes, such as concentration, smelting or electrochemical refining, transform the raw ore into metal and its alloys with varying degrees of purity. It is during this transformation phase that the form of the copper (powder or wire) is defined for use in additive manufacturing.

Copper 3D Printing

As previously mentioned, copper offers good corrosion resistance, which extends the life of printed parts in hostile environments. In addition, with proper process optimization, it can exhibit competitive mechanical properties, including hardness and wear resistance. However, 3D copper printing also presents difficulties.

For example, its relatively low melting point can complicate material fusion and affect the quality of the bond between layers. In addition, copper’s high thermal conductivity can lead to deformation problems during cooling, impacting on the dimensional accuracy of parts. Nevertheless, this metal can be used in additive manufacturing to create parts for the most demanding industries.

There are many copper-compatible 3D printing technologies available today, the most common of which are based on powder systems. Firstly, metal powder bed additive manufacturing (L-PBF, DMLS or SLM) is a process used to create final parts and prototypes in almost all metal alloys, including copper. The quality, strength and density of this technology are far superior to those of traditional techniques. Electron beam melting, also known as EBM (Electron Beam Melting), is an option compatible with copper alloys, ideal for high-end prototyping and small series production.

3D-printed copper parts (photo credits: EOS)

It is also possible to make copper parts with binder jetting. Although pure copper is a difficult material to process at high density using this method, some companies have developed their own solutions to achieve this. In this way, we can take advantage of the geometric freedom and lower costs of additive manufacturing, while creating parts with this conductive metal.

Another additive manufacturing technology compatible with copper is Directed Energy Deposition (DED). Depending on the machine, the metal may be in powder or wire form. Unlike other metal technologies, DED 3D printing relies on the addition of material through a real-time melting process, allowing great flexibility in the creation of complex geometries and the possibility of repairing existing components.

Finally, there are two technologies that are generally used with plastic materials, but which, in certain exceptions, can create copper parts. These are extrusion 3D printing (FFF/FDM) and vat photopolymerization.

For the former, Markforged has developed extrusion solutions capable of working with metal wires. This is the case with Metal X, an FFF 3D printer capable of processing metal powder, enclosed in a plastic binder that is deposited layer by layer. After printing, the part must be washed and placed in an oven to thermally remove the remaining binder and give it all its properties. As for the second technique, companies such as holo, Admatec and Incus have developed their own metal 3D printers, compatible with copper and based on liquid lithography manufacturing.

Main Applications

Given copper’s interesting properties, a wide range of applications can be expected. Whatever the additive technology used, copper stands out for its high thermal and electrical conductivity. This is why many companies use this material to create components requiring good electrical conductivity, such as induction coils, motor windings for electric vehicles, electromagnetic coils, waveguides and antennas, among other examples.

In addition, it is a very useful metal for heat dissipation and heat exchange components, such as cooling plates, heat sinks and heat pipes, temperature exchangers, cooling devices, formed cooling mold inserts, etc. Finally, in the aerospace industry, this metallic material is often used for propulsion systems and rocket engine parts.

Copper and Machine Manufacturers

Depending on the technology used to create copper parts, the metal can come in various forms (mainly powder and wire). Several companies currently offer their copper alloys on the additive manufacturing market. These include Sandvik, Höganäs, Safina and Mitsubishi Materials, as well as EOS, 3D Systems and Elementum.

There are many companies on the market developing not only copper alloys, but also copper-compatible additive manufacturing solutions (photo credits: Beamler).

In addition to the material itself, it’s worth mentioning the companies that have developed additive manufacturing solutions compatible with this metal. These include the aforementioned Markforged, Holo, Admatec, Incus and 3D Systems. But there are also many others, such as Colibrium Additive (formerly GE Additive), Desktop Metal with ExOne, SLM Solutions, Renishaw, Optomec and DMG Mori – the list goes on.

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*Cover Photo Credits: GKN Powder Metallurgy