Making additive manufacturing more cost-effective with Additive Casting

Lattice Structure made using the casting process

Gen3D and Enable recently collaborated on the successful design and production of a complex lattice structure produced using Enable’s Additive Casting® process, which is a hybrid production method combining additive manufacturing and traditional casting. We want to share this project with you because it’s incredibly innovative and demonstrates the creative ways in which Additive Manufacturing is rapidly changing the way in which we manufacture components.

We’re also proud to know that our unique design software, especially the inbuilt manufacturing checks were instrumental in ensuring the success of this part.

Cost savings of up to 80% when compared to DLMS

To cast this complex and small lattice part, which was made in aluminium for use as a heat exchanger, filter or catalyst converter, Enable chose their ultra-fine investment casting process. This process can handle complex geometries which is key to its potential.

It’s not possible to produce a part like this with traditional casting, and when compared to the usual DMLS AM process it’s estimated that cost savings are around 80% when Additive Casting is used.*

Before we detail this specific method and the part itself, let’s look at what Additive Casting is.

What is Additive Casting?

Additive Casting uses additive manufacturing to produce moulds and patterns from which metal parts can be cast. The approach eliminates the need for tooling, allowing for more complex parts to be manufactured than would not be possible with traditional casting. This makes it ideal for production at scale, small runs or even prototypes. Not only is Additive Casting cost-effective, but 130 metals are compatible making it flexible too.

Additive Casting Graph

How are parts cast using additive manufacturing?

The part is designed in CAD in the usual way (or in this case Gen3D’s Sulis Software first) but instead of turning it into a pattern, the 3D solid model is inverted to make a negative of the part. The resulting 3D solid model is of the mould/pattern itself, which is then 3D printed using binder jetting. With binder jetting a liquid binder is used to “glue” material together layer by layer to create a part. After the parts are printed, they are unpacked, depowdered, and waxed (investment casting only) to prepare them for casting.

For thin-walled, highly detailed parts, like the one produced for this project, the printed parts are coated in a ceramic shell and burnt out, leaving a hollow shell that metal can be poured into. For larger parts, sand moulds are used and metal is simply poured straight into the negative impression without any coating needed.

Once the metal has cooled down, the sand mould or ceramic shell is broken to reveal the actual metal parts. These are shot-blasted to improve the surface quality and then the final steps are optional post-production and final inspection.

Enable produces parts, using three Additive Casting processes:

  • Sand casting for large parts (up to 60 tonnes).
  • Investment casting for fine detail (up to 250 x 250 x 250mm).
  • Investment casting for ultra-fine detail (up to 190 x 160 x 160mm)

Achieving a wall thickness of 1.5mm through clever design thinking

‘Our software has built-in manufacturing checks and compensation tools which really helped us to adapt the design parameters to the Additive Casting process, whilst still making sure the part will cast successfully. We were pleased that we could reach a wall thickness of 1.5mm for this cast part, allowing for the design of a perfectly functional lattice structure.’
Steven Goguelin
Stephen Goguelin
R&D Engineer, Gen3D

For this client project, investment casting for ultra-fine detail was used which is ideal to manufacture small, detailed parts and also allowed for the small wall thicknesses required for this particular client project.

The pattern was printed in polymer which was then used for casting the aluminium. A wall thickness of 1.5mm was achieved for this cast part. This is something truly innovative for the casting industry.

Here at Gen3D, if we are asked to consult on a design project similar to this, we would typically design lattice-based components for Direct Metal Laser Sintering (DMLS) which can allow wall thicknesses below 1mm and helps to maximise the surface area within the lattice that air or fluid can pass through.

This part was specifically designed for Enable’s Additive Casting process which meant that some design parameters had to change, a task that Gen3D’s Sulis software could quickly complete.

Filter-Render-Enable-Parts-Casting

Casting 4.0 – casting the un-castable

Using Additive Casting for a complex part like this lattice structure not only ensures high quality but is also cost-competitive. At a unit price of £400 per part for a quantity of 5pcs when produced with Additive Casting compared to £2000 to £6000 per part for the same quantity when produced with DMLS*, Additive Casting is now a serious consideration for engineers developing similar parts.

‘Additive Casting is the perfect fusion of benefits from traditional and additive manufacturing. A part like this could have never been produced with traditional metal casting processes and this is where Additive Casting sets new parameters of what is possible when combining casting with 3D printing. We call this Casting 4.0.’
Phil Kilburn - Enable Parts
Phil Kilburn
Sales Director, Enable
cost-graph-additive-Casting-vs-DMLS-1536x1243
Price comparison between Additive Casting and DMLS for a total quantity of 5 pcs*

*Pricing for DMLS processes was obtained from publicly available online pricing platforms. Please contact us at office@enable.parts for more details.

Time-saving due to reduction of errors, rework, finishing and machining

The business case for metal casting with 3D printing (Additive Casting) is compelling. New designs can be rapidly prototyped and iterated using functional components, not to mention the more complex geometries that this form of hybrid manufacturing enables.

Additive Casting bridges the gap between traditional casting and state-of-the-art manufacturing, offering the volume benefits of casting, cutting lead times and eliminating the need for expensive tooling. We loved working on this client project with Enable and encourage engineers to consider the benefits of Additive Casting.

About Gen3D

Gen3D disrupts the way that industry designs optimised components for additive manufacturing. Founded in 2018, by academics at the University of Bath, Gen3D is a UK-based technology company providing innovative design software and consultancy to industries globally. Gen3D’s flexible and real-time approach to design allows engineers to reduce lead times and lower costs. This makes it ideal for many industry sectors including aerospace, automotive, medical and industrial machinery.

Find more information at www.gen3d.com and Twitter: @gen3_d

About Enable Manufacturing

Enable is bringing a new, innovative manufacturing process to life – Additive Casting. The process uses moulds made via additive manufacturing to cast high-quality production parts from over 130 different metals. It bridges the gap between traditional casting and state-of-the-art manufacturing, offering the volume benefits of casting while increasing possible complexity, cutting lead times and eliminating the need for expensive tooling.

For more information, please contact enable’s office +44 (0) 3333 05 09 04 and office@enable.parts