By Dr Juan Schutte, R&D engineer at UoA’s Creative Design and Additive Manufacturing Lab
Mentioning the word 3D printing (3DP) generally brings visions of plastic filament being melted into rough layered prototypes. This kind of 3DP (Fused Deposition Modelling) led the charge in the dramatic uptake of the technology with machines now commonplace in many New Zealand schools and available from commercial suppliers like Jaycar. While these are certainly useful, it is easy to see how industry reliance on more robust materials like steel, titanium and aluminium could easily mistake 3DP as irrelevant. Thankfully, recently there has been a shift in this paradigm with metal-based technologies (e.g. SLM) seeing greater and growing industrial use.
Industry such as aviation and racing have demonstrated increases in performance and efficiency by leveraging 3DP’s ability to create parts from designs which have been optimised via generative design/topology algorithms. These techniques are manufacturing agnostic and as such typically contain complex shapes which would otherwise be incredibly difficult to manufacture without 3DP. Popular examples include the redesigning of a block manifolds which resulted in an over 90% reduction in weight (Figure A).
While 3DP’s cannot compete with the cost-efficacy of injection moulding as a mass manufacturing technology it has shown promise in the optimising mould tool fabrication. Inserts for which can be manufactured with embedded conformal cooling channels allowing for faster production and increased productivity (Figure B).
While the technology has proven adept at optimising strong industrial parts, the devil is in the detail. 3DP resolution is not yet on par with the capabilities of certain traditional manufacturing techniques. In general, the surface roughness characteristics of metal 3D printed parts is similar to sand casting, as such for most high precision engineering some form of post-print machining/processing is still required.
Metal 3DP is also still clouded by a reputation of being cost prohibitive which is not an entirely fair or accurate representation. While attempting to use the technique to create traditionally designed parts can be very expensive, as shown in Figure A the technology has the potential to create better products at a similar cost if designed appropriately.
Dr. Juan Schutte works at the University of Auckland’s Creative Design and Additive Manufacturing Lab as an R&D Engineer consulting with industry and academia on the opportunities of 3D printing.
The information and opinions within this column are not necessarily the views or opinions of Xpress Engineer NZ, NZ Engineering News or the parent company, Hayley Media.