Best practice for metal additive manufacturing

As industry knowledge in metal additive manufacturing expands, many engineers have successfully evolved CAD models from prototypes into full scale production pieces

As industry knowledge in metal additive manufacturing expands, many engineers have successfully evolved CAD models from prototypes into full scale production pieces

As industry knowledge in metal additive manufacturing expands, many engineers have successfully evolved CAD models from prototypes into full scale production pieces. Many are now asking, “How can I best use this technology in my metal industry?”

When manufacturing using traditional technology, design is limited by tooling restrictions and large production runs are required which usually results in many hours post machining. However, with additive manufacturing, design freedom is limited only by imagination. Solidworks models are easily printed, with small metal manufacturing runs an economical option. As this technology manufactures directly from a CAD model with no tooling requirements, design changes are very quick. Plus, with minimal post machining required, large scale production is very cost competitive compared to traditional methods.

To meet the industry growth, the team at Rapid Advanced Manufacturing (R.A.M) and TiDA have recently commissioned their fourth additive manufacturing machine. They are now printing in Titanium 64, Inconel 718 and Stainless Steel S15-5Ph metal alloys. This now makes them the largest commercial 3D facility in Australasia, and they are still expanding.

With a specialised knowledge of advanced selective laser melting, the design team at R.A.M. is now leaders in this technology. Part of its service is providing design and model suggestions to ensure the best outcome. The biggest consideration when designing a piece is the part shape and volume. Here are a few design pointers to assist in designing specifically for the SLM process;

• In additive manufacturing, cost is based on volume, so the more intricate and hollow the design, the more economical the production.

• Fillets, curves and complex freeform shapes are no problem to the team at R.A.M. In fact, this often assists with the printing process by smoothing the transition between areas of the part.

• Large, thin sections are often built on edge as the distortion and support needed is much less.

• Where possible, circular sections are built with the axis vertical to achieve the highest accuracy.

• Hollow parts are possible and will reduce the deformation, weight and thus the cost of the piece. However, a piece cannot be hollow unless there is a hole for the residual powder to escape through.

• When designing hollow parts, consider the shape of the inside as well as the outside. Any support inside a hollow part is generally impossible to remove and will therefore contain un-melted powder, making the piece heavy and more costly to produce.

• Surfaces requiring a high tolerance or specific surface finish will generally require post machining. Always add sufficient material to the surface to be machined, eg, bearing and sealing surfaces. 0.3-0.5mm is usually sufficient.

In addition to producing parts for machines, they have successfully produced a wide variety of items including; gun suppressors, jewellery, bespoke furniture, aviation and motor parts, marine apparatus, knives, animal implants, giveaways, bike parts, locking mechanisms, winches, badges, dental implants and tooling. Customer confidentiality is an integral part of each project, so although they would like share more of what they do, they cannot discuss some of the exciting pieces they are producing. However, they do attend expos and conferences and present papers and presentations highlighting what they do and how it may be used in different Industries.

R.A.M. also provides a range of polishing options with Raw, Bead Blast, Rumble and hand polishing finishes available. Additionally, they are able to offer heat treatment and specialised PVD coating options using leading industry partners.

To discuss design and printing options, simply send a CAD model to the design Engineers for metal additive manufacturing design advice, build suggestions, costings and post processing options.

Contacts: [email protected], or phone + 64 7 557 8554