How Thin can you Cast with Rheocasting?⚒️
You'll be surprised how thin the wall thickness can be!
This week’s newsletter contains the following topics:
Much thinner than you'd expect!
In traditional high-pressure die casting (HPDC), wall thicknesses below 2 mm are considered exceptional and are rarely achieved. But Rheocasting changes the game entirely.
Why Conventional HPDC has its Limits
In HPDC, liquid metal is injected at high speed into a mould cavity. It splashes and spreads in all directions, easily reaching complex geometry. That’s great for many shapes, but not for everything.
Rheocasting works differently. The semi-solid metal slurry flows in a much more controlled, directional manner. Instead of spreading wildly, it tends to move straight ahead through the cavity. This means it might initially bypass perpendicular features, such as a rib extending sideways, and only fill them later, once its main flow path encounters resistance.
In conventional HPDC, the liquid metal can splash into thin ribs and quickly solidify. Rheocasting’s globular, laminar metal flow avoids many of those issues, provided air can escape. If venting is done right, even very tall and thin ribs can fill completely and defect-free.
How Alloy Choice Affects Castability
The alloy you choose also plays a significant role. Take a near-eutectic alloy like AlSi10MnMg. It offers good flowability, making it easier to fill narrow features. However, its relatively low thermal conductivity makes it less ideal for heat-sensitive applications.
Here’s why: In HPDC, the high silicon content and dendritic microstructure reduce the flow of electrons and with it, thermal performance. These materials often max out around 140 W/mK. That’s not enough for demanding applications like 5G antenna systems, which generate high heat loads and require top-tier conduction to avoid overheating.
When a heat sink can’t manage heat effectively, electronics suffer. Signal range drops, systems shut down, and the cost of network deployment rises. You could use an active cooling system to help, but that adds cost, complexity, and even attracts wildlife looking for shelter.
In Rheocasting, the castability is independent of the silicon content. As long as the alloy is rheocastable, which the AlSi10MnMg is not, the castability is equally good.
So, How Thin Can You Go?
It depends on the flow distance. With Rheocasting, 2 mm wall thickness for structural castings is routine. Heat sinks with walls as thin as 0.8 to 1.5 mm at the tips, using steeper draft angles, are also achievable. That’s a major weight advantage over conventional HPDC, which requires thicker walls and gentler angles.
Some parts, such as the radio filter in the picture, even achieve a wall thickness of 0.4 mm in the as-cast condition, requiring no machining. Even more impressive, the large adjacent bosses, over 10 mm thick, remain porosity-free.
The Rheocasting Advantage
Rheocasting provides full flexibility to adjust wall thickness precisely where needed, without compromising quality or strength. So, you no longer need to stick to the 3–4 mm standard solely to ensure metal flow. By optimising wall thickness:
You save weight
You reduce material costs
You lower carbon emissions
All while maintaining or improving structural performance. To learn about how Rheocasting can transform your product portfolio, the Rheocasting Workshop from Casting-Campus GmbH is perfect for you.
How effective is the Goldcasting Podcast?⚒️
As we know, active marketing in the foundry industry is, for many, something new or something they have never done. Still, we want everybody to know about the latest product or service.
A significant portion of marketing happens on domain-specific channels. I picked two typical foundry channels where you can place your message by paying for it. Both of these Channels have way more than 5000 followers. And benchmarked it against the Goldcasting Podcast, which has 842 followers. The data shown is just on LinkedIn.
YouTube, newsletters, and websites are not included in that data. However, you rarely go on websites and look for topics you don’t know. With a podcast, it is different. A podcast is an integral part of many people’s daily lives. You listen to it when you’re on the way to a customer or supplier, in the gym or just for fun.
You’re Paying for Awareness
When you sponsor content, you’re not always buying clicks or leads. More often, you’re buying attention, credibility, and visibility; in other words, brand awareness.
In a long, multi-stakeholder B2B buying cycle, brand awareness plays a critical role. It makes your company recognisable before a decision-maker ever visits your website or talks to sales. It builds familiarity and trust. The kind that shortens sales cycles and improves win rates over time.
Just because awareness is hard to quantify doesn’t mean it’s not valuable. On the contrary, it’s often the foundation of successful demand generation.
When you can’t track direct attribution, engagement becomes one of your most useful signals. Metrics such as likes, comments, shares, and mentions provide early indications of how your message is resonating. If engagement is high and comes from the right people (e.g., those in relevant roles, companies, or verticals), it’s a strong signal that your brand is making a positive impact.
What does the Data say?
Let’s examine the numbers. The data is publicly available on LinkedIn, and I reviewed it over the last 30 days. All three channels are between 15 and 21 posts. However, the reaction to these posts is vastly different. Channel 1, on average, gets just nine likes, comments, and shares. Channel 2 wins that comparison with 22 engagements. The Goldcasting Podcast falls in the middle, with 14 engagements per post.
Each of these Channels posts one article/post with your message. That is your one chance to make a lasting impression on LinkedIn. The Goldcasting Podcast focuses on your message for 2 weeks, resulting in a total of 113 engagements. With different dates, times, and content formats, we reach a wider audience. That is 5 to 12 times the impact!
So, what are you waiting for? Use this opportunity to become part of one of our Gold Nuggets to share your message with your new customers! Schedule the Free Consultation Call on the website.
About lighter Rotors and cleaner Castings⚒️
Spartan Light Metal Products, a family-owned die caster with four facilities in the St. Louis region, has turned Rheocasting from a laboratory curiosity into a daily production asset. By focusing on two very different programs, the company demonstrates how semi-solid processing can enhance quality, reduce carbon footprint, and strengthen the bottom line simultaneously.
A Breakthrough Brake Rotor
The most eye-catching result of Spartan’s Rheocasting work is a patented all-aluminium brake rotor. Engineers revived a hyper-eutectic alloy that Spartan had co-developed with NASA in the 1990s for extreme wear resistance. They then cast this alloy in a semi-solid form on the first Comptech slurrymaker in the US. The finished rotor weighs only 13 pounds, compared with 33 pounds for the cast-iron disc it replaces, so each wheel sheds 20 pounds of unsprung mass.
Friction and wear levels match those of iron, while noise levels are noticeably lower. For electric vehicle designers who strive to reduce every kilogram of weight, a four-wheel package that removes eighty pounds while maintaining traditional braking behaviour is a compelling proposition. The part is now patent-protected and ready for an OEM launch partner.
Cleaner and Stronger A380 Castings
While the rotor demonstrates what is possible at the hyper-eutectic side, Spartan has also upgraded everyday production parts by switching standard A380 alloy to Rheocasting. By adjusting the silicon content within the specification, the company maintains the material designation familiar to OEMs while improving recyclability and toughness. Semi-solid pouring temperatures are roughly sixty degrees Celsius lower than those of liquid high-pressure die casting, which immediately cuts furnace energy demand.
The slurry fills long ribs, bosses, and pockets with far less turbulence than liquid metal. X-ray sections reveal markedly reduced gas and shrink porosity, and early shop-floor data indicate that die life roughly doubles because of the lower thermal shock. Parts that once required a 6,000-ton press now run on a 4,400-ton machine, freeing up larger capacity for new work and saving additional energy with every cycle.
Quality and Sustainability in the same Package
Every major process lever in Rheocasting delivers both financial and environmental dividends. Lower melt temperatures reduce utility bills and carbon emissions in equal measure. Longer die life postpones expensive tool rebuilds and avoids the steel scrap that comes with them. Improved yield means fewer rejects, less re-melt, and less landfill waste. Spartan has even patented a porosity-repair technique that salvages castings that would typically fail leak tests, turning potential scrap into revenue and reducing carbon footprint per finished part.
Because the compounding gains stem directly from process physics, cooler metal, laminar flow, and slower die-filling, they do not depend on subsidies or green premiums. The savings appear naturally on the profit-and-loss statement, which makes it easier for management and customers alike to support further deployment.
Conclusion
Spartan’s aluminium brake rotor demonstrates that Rheocasting can meet demanding functional requirements. At the same time, the company’s upgraded A380 castings confirm that the same process can enhance routine production quality without the need for exotic alloys or giga-presses. By applying semi-solid technology where it makes both technical and financial sense, Spartan demonstrates that lighter rotors, cleaner castings, and a healthier bottom line can go hand in hand—right now, on equipment that many die casters already own.
Thank you for listening. We’ll see you in the next episode, where we’ll continue to bring you the latest insights and updates from the casting world. Don’t forget to ask questions, comment, or suggest future episodes.
Offers from Casting-Campus GmbH
Casting-Campus is all about helping you acquire new business through intelligent solutions, new technologies like Rheocasting, and sustainability.
Our services start with positioning your foundry. The next steps are to find unique solutions to market to existing and new customers and generate new profitable castings. In the meantime, we will improve your internal processes to accommodate the new solutions in your foundry. During the sampling process, we’re by your side, pushing the buttons to deliver the properties promised in the development process.
Workshops on HPDC process optimization, Rheocasting and Sustainability
Business Development to acquire new Customers in the Foundry Industry
Strategy Development for Rheocasting and Sustainable Castings
Casting Experts on Demand - The Netflix of Knowledge
Support for part development: address casting issues early in the design process
If this sounds appealing to you, visit the website for more information on the Consulting Services and schedule a Free Consultation Call. Let’s discuss what the right solution is for your topic of interest:
Historical Post
A weekly reminder of an old but gold article
Megacastings will be the most sustainable Castings⚒️
By just reading this headline, it sounds wrong. Megacastings require large DCMs, tools that weigh over 100 tons, massive amounts of aluminium, and an armada of heating devices. How can this colossal monster of a casting process be sustainable?
Let's go through these points and then add a twist. The large DCMs, just like the small ones, can produce parts for decades. Once they're installed, they produce generations of vehicles. And they're efficient while doing that. As you can see in my "Megacasting Rocks"-Video, the support system is tiny in size comparison.
Their origin defines the carbon footprint of the used steel and aluminium. The steel industry has advanced recycling routes compared to the aluminium industry. The main reason for that is the position of iron in the electrochemical voltage series. Every impurity in the scrap will stay within the melt of the recycled aluminium.
That is why megacastings will enable the development of the world's most sustainable cars. When you look at a current body-in-white structure like in the picture below, you can see a lot of castings, beams, and sheet metals. After years of service, you must disassemble everything for recycling. So, you need to determine the alloy specification for each part and separate it from the rest. But be aware that the parts are welded, screwed, glued, and riveted together. These joining methods must be separated because you cannot tolerate steel rivets in your recycling process. This process is labor-intensive and, therefore, expensive. Who is going to pay for that? Probably not the broad market.
Imagine a car made from three castings: front- and rear Megacasting and a battery box casting. Recycling will be easy if you replace that conglomerate of parts with three megacastings. Therefore, most of the alloy can be used for the next megacasting because it is easy! If we want to enable a circular economy, we must design it from the start.