How Simulation Tools Improve Casting Quality and Reduce Waste
The factors which cause high scrap rates and a constant need for rework often come from the things you can’t see happening inside the mould/pattern. In today’s automotive engineering world, however, simulation software is available to engineers, which gives them a detailed, predictive view of what will happen before the casting process begins.
Simulation in automotive manufacturing has given under-pressure lead engineers a solution which reduces revisions and can deliver first-time-right castings.
In this blog, we’ll explore the tangible outcomes of casting simulation tools and show how first-shot success no longer needs to be based on guesswork. As well as that, we’ll show how it supports all manner of goals, both economic and environmental.
The use of digital validation in the casting process is a smart step forward in reducing carbon-intensive scrap rates, and by the end of this blog, you’ll see why and see how BCW Engineering is at the forefront of this movement.
What is simulation in casting, and why does it matter?
Casting simulation takes the guesswork out of the legacy casting process by predicting what is going to happen inside the mould during fill, solidification, and cooling.
Simulation tools use thermal modelling to simulate the real-world outcomes before the metal is poured.
This sort of modelling allows engineers to visualise:
- Hot spots
- Porosity
- Shrinkage
- Filling behaviours
- Accurate cycle times
- Cooling and venting
Simulation shifts problem-solving from reactive to proactive, a priceless alteration for engineers when you consider they’re juggling deadlines, reworks, and CO2e targets.
By looking at all these factors in a virtual environment, engineers can spot tooling issues before it’s too late. Before this, it was only after the process had been completed that parts were seen to have failed and tolerances had drifted.
Simulation has been made possible with software like MAGMASOFT and ESI ProCAST, which gives clear feedback at the design and tooling stage. Both pieces of software help to simulate defects early and reduce the number of physical iterations of parts. All of which has obvious economic and environmental benefits – both of which we’ll explore later.
Today’s engineers no longer need to have learnt expensive lessons from trial and error. They now have reliable data on their side, allowing them to predict the future and make informed decisions. All of this helps to increase confidence in tooling design and material flow for aluminium casting in particular, where solidification happens rapidly.
How casting simulation reduces scrap and rework
The costs involved in scrap and reworks is a key reason why so many engineers are investing in simulation software. It reduces both those factors by detecting defects before tooling is cut to improve material flow and prevent misruns.
Proper simulation allows you to adjust several factors that improve part integrity, including:
- Gating
- Runner systems
- Cooling and venting
Porosity from poorly designed parts causes scrap rates to be in the double digits, with some estimates ranging between 15% and 25%. Simulation has helped to reduce this to, in some cases, below 5%.
Engineers can use simulation to identify defects and link them to their cause. Whereas one might have been put down to random variability, defects can now be traced back to design, process, or something else.
Additional flow and thermal simulation can highlight areas where metal might not fill or solidify and ensure consistent cooling across sections to reduce part stress.
All this keeps engineers informed without needing to react to unexpected changes.
More proactive ways to reduce scrap and rework can also be gleaned from reworks by allowing engineers to test “what if” scenarios.
These sorts of scenarios would not have been possible pre-simulation, as it was simply too expensive to test changes on real parts. Today, however, simulation can show what would happen if alloys were changed, wall thicknesses were tweaked, or tool temperature settings were altered.
When everything mentioned above is combined, rework is dramatically reduced because poor first-shot outcomes are removed from the equation, thanks to the ability to simulate.
How does thermal modelling support tolerance control in aluminium casting?
Thermal modelling improves tolerance control by managing solidification rates to ensure uniform cooling across parts with complex geometries. Greater tolerance control, such as this, supports supply chain reliability and reduces late-stage tooling adjustments.
One of aluminium castings’ great properties is its ability to solidify rapidly. Unfortunately, this also means that small imbalances can create large tolerance variations that cause parts to be scrapped or need additional rework or additional processing such as CNC machining.
Simulation helps prevent this by highlighting areas where residual stress or hotspots could lead to dimensional instability after the parts have been ejected from the die casting machine.
Once these areas have been highlighted, engineers can act to adjust tool cooling and wall thickness, both of which go a long way to reduce thermal hot spots. When solidification is controlled in this way, it helps to improve dimensional accuracy and reduces the need for post-cast processes such as CNC machining.
And, as these distortions become known, thanks to the simulation data, casting can then be tweaked to compensate for them. This helps to avoid overdesigning parts with excess stock in case something goes wrong, reducing cost and machining time.
Simulation data helps confirm whether a feature will be within spec once it’s moved up to production scale and brings a tighter alignment between casting geometry and first-time-right DFM goals.
How can simulation support carbon and cost reduction targets?
Simulation supports ESG goals and cost reduction targets by reducing energy use and minimising scrap. Simulation is particularly beneficial at reducing emissions scopes 1 and 2 because of the way it can predict problems before they are spotted after the casting process has finished.
Simulation allows engineers to prototype parts without having to create physical versions, helping to reduce time and tooling costs. And by optimising fill and cooling processes in a simulation, overall cycle times are reduced, keeping the energy used per part down.
These predictable outcomes reduce the need to use unnecessary energy and resources, a tangible ROI for OEMs under pressure from Carbon Border Adjustments Mechanisms (CBAM), and the like.
While scope 1 and 2 emissions are directly reduced because of the simulation, scope 3’s impact is also mitigated. A greater material yield during the casting process, thanks to simulations, means logistics are simplified and reduced. There are fewer production delays and rejections that often lead to programme delays and warranty risks.
Using simulation data to show proactive emission reduction supports supplier transparency and is something suppliers looking to work with Tier 1s and OEMs should be looking to implement as standard.
What’s the ROI of casting simulation, and when should you use it?
Casting simulation provides a return on investment by reducing tooling iterations and improving yield. It should be used at the quoting, tooling design, or the New Product Introduction (NPI) stage for it to be at its most effective.
Simulation reduces the risk of late-stage design/tooling changes that so often disrupt launch timelines. Engineers can further measure the ROI of casting simulation in:
- Fewer rejected castings
- Reduced sign-offs
- Optimised cost
Engineers can now back their recommendations up with data, as opposed to having to just rely on their instinct, and the reduction in tooling modifications that occur as a result of these recommendations can save tens of thousands in cost and a significant amount of time as well.
Simulation’s ROI expands to improved first off sampling performance, which not only creates conforming quality components but also improves trust with customers and programme stakeholders. Today’s digital simulation solutions are no longer premium tools but a cost-saving necessity.
The simulation edge: casting with confidence, not compromise
Simulation isn’t just about using new software. It’s about shifting mindsets. Engineers need to move away from guesswork and instead harness the predictability and data that simulation provides for factors like porosity, shrinkage, and tolerance stability.
Thermal modelling and flow analysis can now all be validated digitally, helping to bring casting into the data-driven era. Errors are reduced at source, something that’s essential for aluminium die casting, where accuracy and repeatability are critical.
For OEMs and Tier 1s under pressure to offer improved ESG numbers, simulation reduces scrap and fast NPI cycles. All this delivers improved CO2e numbers without compromising part quality.
At BCW Engineering, we are committed to smart casting solutions that help our partners not only benefit from more predictable casting processes but also to help mitigate their environmental impact as much as possible.
