Commercially pure copper is a highly desirable material for heat exchangers and electrical components due to its excellent thermal and electrical properties. While these properties are beneficial for the application, they also turn the process of using copper in additive manufacturing into a challenge.
In collaboration with global engineering technologies company Renishaw, this article explores how to overcome this issue and the use of additive manufacturing to produce intricate and complex copper structures for heat exchangers.
Copper 3D Printing Breakthroughs
“Additive manufacturing (AM) is a breakthrough technology that is transforming the manufacturing industry,” explained Kenneth Nai, Principal Engineer at Renishaw. “This digitally-driven process gives engineers the design freedom to create and manufacture parts with complex structures that would never have been possible with traditional machining.”
Traditionally, heat exchangers are made from thin sheets of material that are welded together. The complex geometry of heat exchanger designs makes production challenging and time-consuming. AM systems build parts layer-by-layer, only adding material where needed, to produce lightweight yet complex components, making this process attractive for manufacturing heat exchangers.
“While its high thermal conductivity makes copper the ideal material for heat exchangers, the properties of the material can create challenges when using an AM system,” continued Nai. “The laser sintering of copper powder with an infra-red laser at a wavelength of 1070 nm is difficult because copper is very reflective at that wavelength. Therefore, only a small amount of the laser energy is absorbed into the powder, and a critical threshold of absorption is required to melt the powder together. Combining the high thermal conductivity of copper and the laser energy required, leads to instability and often results in poor mechanical properties of the finished part.”
Renishaw has collaborated with nTopology to demonstrate to manufacturers that, by using the right software and system together, they can reliably additively manufacture intricate structures from copper.