Electrically conductive composite material for additive manufacturing

Important results from the project

We have fulfilled the goals that we did set, to investigate several sources of graphene and have investigated the flow and melt blending characteristics. Melting tests show that the mixing during melting of the various graphene and PA powder is not good enough. The insufficient wetting between the graphene materials and PA powder is what causes this problem. This was the most important insight in this pre study. The melt mixing will be the most important aspect to improve, and will be one of the aims of the full project application

Expected long term effects

The melt mixing will be the most important aspect to improve. Promising methods to achieve this includes plasma treatment of the PA powder and the graphene material. Also, functionalization of the graphene material already at the production by various methods is of great interest. The time to a product can be fairly short if the issues are solved, the interest from industry of new functional AM materials is large and the AM machines are available.

Approach and implementation

The graphene materials tested were Graphene oxide (GO) in solution, high porosity reduced graphene oxide (rGO) and exfoliated graphene in different amounts. The GO in solution were mixed with PA powder, then reduced to rGO and finally the powder was dried. The other two types were dry mixed. It was found that mixing in solution caused lump formation, which gives problems for the flowability of the material. The dry mixing works better in this regard, but it could be possible to grind the wet mixed material.