A new chapter in metal 3D printing. Discover how Molten Metal Deposition makes aluminium FDM fast, affordable, and finally viable for industry.
Table of contents
- Introduction to FDM and aluminium FDM
- How aluminium FDM works: the evolution from plastic to metal
- The ValCUN advantage: Molten Metal Deposition technology
- Advantages of aluminium FDM via MMD
- Materials: from aluminium-filled filaments to pure aluminium
- Industrial applications of aluminium FDM
- Aluminium FDM vs. other 3D printing technologies
- Why choose MMD for aluminium FDM?
- Challenges and solutions in aluminium FDM
- The future of aluminium FDM
- Frequently Asked Questions
- Conclusion
Introduction to FDM and aluminium FDM
Fused Deposition Modeling (FDM), also known as Fused Filament Fabrication (FFF) in academic circles, was invented in 1985-1986 by Scott Crump who founded Stratasys. FDM is the most widespread 3D printing technology globally. Traditional FDM works by extruding thermoplastic materials layer by layer to build three-dimensional objects. When Crump’s patents expired in the early 2000s, the technology exploded with affordable printers entering the market at €300-500, making 3D printing accessible to businesses and hobbyists alike.
However, the holy grail of FDM/FFF technology has always been metal printing, particularly aluminium. The challenge of aluminium FDM/FFF has proven extraordinarily difficult – even with all the resources and expertise of major companies like Ultimaker, Desktop Metal, prestigious institutions including MIT, Fraunhofer Institute, as well as numerous startups, reliable aluminium FDM printing remained elusive for decades.
ValCUN, our scale-up company from Ghent, Belgium, has achieved what others couldn’t: successfully printing aluminium using a revolutionary approach called Molten Metal Deposition (MMD). This breakthrough introduces a new approach to metal additive manufacturing, making aluminium printing cost-effective, scalable and ready for industrial use.
Related content: For a comprehensive overview of aluminum AM challenges across all technologies, see our complete technology comparison guide.
How aluminium FDM works: the evolution from plastic to metal
Traditional FDM with thermoplastics
In conventional FDM, thermoplastic filament is fed through a heated nozzle where it melts and is deposited layer by layer. The key characteristic of polymers that makes this process possible is their viscosity at elevated temperatures. They behave when heated like a paste eg. chocolate, maintaining enough thickness to be deposited accurately and stay in place.
The aluminium challenge
Aluminium presents a fundamental challenge: when molten, it has the viscosity of water rather than the honey-like consistency of thermoplastics. Imagine trying to build a structure by depositing water with a syringe. It would simply flow away. This is why traditional FDM approaches fail with aluminium.
Three approaches to aluminium FDM
The industry has developed three distinct approaches to aluminium FDM:
- FDM with polymer filament filled with aluminium powder (debinding-sintering approach). This method uses a polymer filament filled with aluminium powder. After 3D printing with the benificial properties of the polymer, the part undergoes debinding (removing the polymer through burning or chemical dissolution) and sintering (heating under pressure to fuse the aluminium particles). The process requires 12+ hours for debinding and 24+ hours for sintering, despite advertising only 3-hour print times. So the time-to-part is significantly longer than the time-to-print.
- Direct aluminium extrusion in thixo state (Failed attempts). Few major companies and research institutions have tried directly extruding aluminium wire in its thixo state. In this way, the deposited aluminium behaves like a viscous paste. To keep the aluminium in the thixo state, the process window becomes very small, and the maximum part height is limited to a few centimetres. This approach fails because the supplied energy required for bonding is not sufficient, leading to a lack of fusion and poor quality parts. If basic physics shows you wrong, engineering will not solve the issue.
- Direct aluminium extrusion in liquid state (Molten Metal Deposition, MMD) ValCUN is the only company worldwide that has successfully developed direct aluminium printing using pure aluminium wire feedstock. Their patented technology controls the flow properties and temperature of molten aluminium, achieving what no one else could.
Related reading: Understanding why Aluminium Binder Jetting requires 40+ hours of post-processing while MMD delivers parts in hours.
The ValCUN advantage: Molten Metal Deposition technology
How MMD works
ValCUN’s MMD process involves feeding aluminium wire into an electrically heated crucible where it melts above the liquidus temperature. The fully molten metal is then extruded through a nozzle in a controlled manner, with the motion of the wire controlling the flow. The extruded metal is deposited layer-by-layer, and the energy in the fully molten material ensures optimal fusion between layers.
Key technical features
- Controlled volumetric extrusion: The system ensures that the volume of solid wire fed into the printhead is precisely what is extruded, using multiple sensors, feedback loops and complex control systems to ensure controlled volumetric deposition.
- Temperature control: The printhead and crucible design allow precise thermal management of the molten aluminium during deposition, crucial for overcoming the challenges others faced.
- Single-step process: Unlike powder-based methods, MMD is a single-step process. Once printing is complete, parts can be removed from the build plate within seconds—no debinding, no sintering, no wire-EDM, no additional post-processing required.
Advantages of aluminium FDM via MMD
1. Lightweight and strong
Aluminium combines low density with high structural integrity, making it ideal for applications requiring strength without weight penalties. The design freedom of Additive Manufacturing allows for topological optimisation or infill structures, enhancing the strength-to-weight ratio of the aluminium AM part.
2. Cost-effective production
ValCUN’s process reduces production costs by 75-90% compared to powder-based methods. The elimination of post-processing steps (debinding, sintering, wire-EDM, milling) that can take 40+ hours, significantly improves time-to-part.
3. Rapid prototyping and production
With print speeds 10x faster than traditional AM methods and immediate part availability after printing, MMD enables true rapid prototyping and serial production.
4. Environmental benefits
The process avoids the environmental hazards of burning polymers during debinding, eliminates explosive aluminium powder handling, and significantly reduces material waste compared to CNC machining.
5. High-strength alloy compatibility
ValCUN’s technology can process high-strength aluminium alloys (6xxx and 7xxx series) that are considered non-weldable and unprintable with other technologies, opening new possibilities for industrial applications.
Related content: See real production applications including the Addcat 8-fold cost reduction in our Liquid Aluminium Printing case studies.
Materials: from aluminium-filled filaments to pure aluminium
Material categories
- Aluminium-filled polymers These materials contain polymer binders filled with aluminium powder, used in debinding-sintering approaches. Whilst marketed as aluminium printing, they require extensive and very complex post-processing and have severe limitations due to the difficult nature of aluminium sintering. ValCUN thus does not use aluminium-filled polymers.
- Pure aluminium wire ValCUN focuses exclusively on 100% pure aluminium wire feedstock—no additives, no grain refiners, no salt and pepper, no plastics, just pure aluminium and its industry-known alloys. This enables true single-step processing without compromising material properties. The material composition of the final part has been known and trusted for decades in the industry.
Industrial applications of aluminium FDM
1. Industrial manufacturing
Custom tooling, jigs, fixtures, and replacement parts benefit from on-demand aluminium printing capabilities.
2. Electronics and thermal management
Heat sinks, cooling elements, and electronic enclosures benefit from aluminium’s thermal conductivity and MMD’s design freedom.
3. Defence
Field-deployable manufacturing, spare parts production, and mission-critical components benefit from MMD’s ability to operate in remote environments where traditional supply chains fail.
4. Automotive
Lightweight structural components, heat exchangers, and prototype parts for electric vehicles leverage aluminium’s properties.
5. Aerospace
Whilst certification processes are lengthy, aerospace applications represent significant future potential for complex aluminium structures. With FDM having a proven track record in low-gravity, space and the ISS (International Space Station) for polymers, the same FDM advantages will now come to aluminium in space.
Aluminium FDM vs. other 3D printing technologies
Technology comparison
| Feature | MMD (ValCUN) | Powder Bed Fusion | Binder Jetting | Wire Arc AM |
| Input Material Cost | Low (€10/kg wire) | High (€100/kg powder) | High | Low |
| Post-Processing | Minor | Extensive | Extensive (40+ hrs) | Moderate |
| Safety | High (no powder) | Low (ATEX required) | Low | Moderate |
| High-Strength Alloys | Yes | Limited | Very Limited | Limited |
| Time-to-part | Fast | Slow | Slow | Fast |
| Resolution | 0.5-1.5mm | <0.1mm | 0.5mm | >2mm |
| Energy Efficiency | High | Very Low | Low | Moderate |
Related reading: Compare all aluminum 3D printing technologies in detail in our comprehensive technology guide.
Why choose MMD for aluminium FDM?
MMD offers unique advantages: no powder handling requirements, no need for support structures due to its ability to print overhangs >70° and bridge >20mm in air, and the ability to print in any orientation including upside-down printing. The technology’s energy efficiency comes from melting aluminium within an insulated printhead rather than using high-power lasers shooting on a very reflective surface and high thermal conductive material.
Challenges and solutions in aluminium FDM
Challenge 1: Material flow control
Problem: Aluminium’s water-like viscosity when molten. ValCUN Solution: Patented technology that controls the flow properties of molten aluminium, achieving what no other company worldwide has managed.
Challenge 2: Oxidation
Problem: Aluminium oxidises rapidly at high temperatures. ValCUN Solution: The lower process temperatures and reduced exposed surface area significantly minimise oxidation. For Al-4xxx series alloys, shielding gases aren’t even required.
Challenge 3: Thermal stress and cracking
Problem: High-strength alloys crack during traditional AM processes. ValCUN Solution: The low cooldown rates achieved by MMD eliminate deformations and solidification cracking. The lower operating temperatures eliminate the likelihood of evaporation of lighter alloying elements like Mg. All these advantages enable the printing of traditionally “unprintable” alloys like AL-6xxx and Al-7xxx series.
Challenge 4: Post-processing complexity
Problem: Traditional metal AM requires extensive post-processing. ValCUN Solution: Single-step process with parts ready for use within one minute of printing completion—no cutting tools, debinding, or sintering required. The part pops from the build plate just like with polymer FDM.
The future of aluminium FDM
ValCUN’s technology is capable of printing all metals including Magnesium, Copper, Steel, and others; though the company is strategically focusing on becoming the world leader in aluminium alloy printing before expanding its material portfolio. The successful development of MMD represents not just an incremental improvement but a fundamental breakthrough that makes aluminium FDM practical for industrial production.
The implications are significant: from reducing the environmental impact of manufacturing to enabling on-demand production of complex aluminium parts, MMD technology is poised to transform how industries approach aluminium component manufacturing.
Frequently asked questions
Can you print pure aluminium alloys with FDM?
Damn right, ValCUN’s MMD technology uses 100% pure aluminium alloy wire feedstock without any additives or plastics, achieving true aluminium FDM printing.
How strong are aluminium FDM-printed parts?
MMD-printed parts achieve mechanical properties of +90% of the feedstock strength and similar ductility. Including the ability to print virgin high-strength alloys (Al-6xxx and Al-7xxx series) that other technologies cannot process.
What’s the difference between aluminium FDM and Molten Metal Deposition?
MMD is ValCUN’s specific implementation of aluminium FDM, using controlled extrusion of fully molten metal rather than polymer-bound powder or other direct wire approaches.
What post-processing is needed for aluminium FDM prints?
With ValCUN’s MMD technology, no post-processing is required. Parts are ready for use immediately after printing, unlike powder-based methods that require 40+ hours of debinding and sintering.
Conclusion
The journey from Scott Crump’s original FDM invention to successful aluminium printing has taken nearly 40 years, with countless failed attempts by industry giants and research institutions. ValCUN’s breakthrough in Molten Metal Deposition represents the culmination of this journey, finally making aluminium FDM a practical reality for industrial production.
As the only company worldwide to successfully print aluminium using direct wire extrusion, ValCUN is currently redefining what’s possible in metal additive manufacturing. For industries seeking cost-effective, rapid, and reliable aluminium part production, the wait is finally over.
Ready to revolutionise your aluminium manufacturing? Contact ValCUN’s experts today to discover how Molten Metal Deposition can transform your production capabilities. Learn more about our Aluminum Additive Manufacturing solutions or explore our insights on Molten Metal Deposition technology.