Mr. John Martin, an Assistant Professor of Engineering Technology, published this article in November 2017.
Title: “Exploring Additive Manufacturing Processes for Direct 3D Printing of Copper Induction Coils – Symposium on AM: Novel Applications session.”
Author: John Martin
The production process of creating custom induction coils is often a tedious and time-consuming procedure, which is largely due to the fact that the coils are created by hand for the most part. Generally each coil is a specialized size and shape depending on customer requirements so there is very little repeatability involved in the production process of these products. This paper looks at the practicality of printing copper induction coils that could provide appropriate material properties, such as electrical conductivity. The paper also focuses on which printing method(s) might be the most efficient and/or practical. There has been little research done on the 3D printing of copper material compared to other metals such as steel, and the majority of research that has occurred focuses on material properties; mainly thermal conductivity. This study focuses on the practicality of the printing of the physical shapes, specifically a hollow curved or spiral shape. The most common and successful method that has been used thus far utilizing additive manufacturing (AM) for the production of copper parts is investment casting, where the mold is created using AM. While this method has merits, it isn’t a directly printed part. Also successfully casting a hollow curved or spiral shape would be extremely difficult and likely not practical. Induction coils can take on a seemingly unlimited amount of shapes and sizes. However, typically there tends to always be two main characteristics for a coil, those are: some type of hollow tubing is utilized for water cooling, and the existence of curved paths. These two characteristics in combination present some difficult hurdles regarding the physical printing of the part. Another major difficulty is the fact that the final material must be very dense in order to afford the superior electrical conductivity properties, which standard copper used for electrical purposes has. The main processes inspected for this study are powder bed fusion, namely selective laser melting, selective laser sintering, electron beam melting as well as direct energy deposition, using either powder or wire for the material feed. After considering all the various techniques for applying additive manufacturing to create induction coils, the selective laser melting process seemed to be the most practical and showed the most promise.