Every aluminum droplet from Liquid Metal Jetting oxidizes before it lands. The physics can’t be fixed. That’s why we developed something different.
In essence, Liquid Metal Jetting builds aluminum parts by depositing molten droplets with 50-micron precision. No powder, no laser, just controlled droplets of aluminum creating geometries impossible with other methods. The US Navy prints parts with it on warships. ADDiTEC acquired the technology from Xerox with over 300 patents.
We evaluated the technology extensively before developing our own aluminum AM system. The physics told us everything we needed to know: every droplet oxidizes in flight, thermal gradients limit build height to 10cm, and achieving consistent properties across millions of deposition events is statistically improbable.
This technical analysis examines how Liquid Metal Jetting works, where it genuinely excels, and why we developed continuous flow MMD for production manufacturing instead.
Table of contents
- Understanding Liquid Metal Jetting technology
- The droplet problem we couldn’t ignore
- The thermal reality of droplet deposition
- Why we developed continuous flow
- Process comparison: technical capabilities versus production requirements
- Liquid Metal Jetting’s application landscape
- Real production economics
- The alloy advantage nobody discusses
- Real customer results: Production economics in action
- What Liquid Metal Jetting research reveals
- The future of aluminum AM
New to Aluminium AM? For a complete overview of all aluminum 3D printing technologies and their limitations, see our comprehensive technology comparison guide.
1. Understanding Liquid Metal Jetting technology
Liquid Metal Jetting generates molten aluminum droplets between 20-100 microns and deposits them at frequencies up to 1000 Hz. The concept is elegant. First, melt aluminum wire at 660°C, use piezoelectric or pneumatic actuation to create droplets, deposit them precisely where needed.
ADDiTEC’s ElemX system, acquired from Xerox, represents the current state of the art. The US Navy successfully deployed it aboard the USS San Diego, printing Al-6061 replacement parts at sea.
Indeed, the resolution is genuinely impressive. With 20-100 micron droplets, Liquid Metal Jetting creates features that challenge other metal AM processes. Microfluidic channels, precision cooling passages, hydraulic manifolds with 500-micron internal features all become possible with LMJ.
Importantly, LMJ uses wire feedstock instead of powder, eliminating the explosion risks and ATEX facility requirements associated with aluminum powder handling, which is a major advantage over powder-based approaches..
2. The droplet problem we couldn’t ignore
During our evaluation, we instrumented a droplet system with high-speed thermal imaging and spectrometry. What we found matched the 2022 Journal of Intelligent Manufacturing study: massive variability.
Droplet size varied by 15%. Furthermore, velocity fluctuated by 20%. Yet, the killer was oxidation.
At 660°C, aluminum’s affinity for oxygen is -1,045 kJ/mol. The activation energy for oxide formation is essentially zero. Even in 99.999% pure argon (10 ppm oxygen), oxide forms in nanoseconds. Atom probe tomography studies confirm 3-5 nanometer oxide shells on every droplet.
Consequently, for a 50-micron droplet with surface area to volume ratio of 120,000 m⁻¹, that oxide represents 2-3% of the droplet volume. When you’re depositing millions of droplets, that’s millions of ceramic interfaces preventing proper metallurgical bonding.
3. The thermal reality of droplet deposition
A 50-micron aluminum droplet at 660°C contains 3.4 × 10⁻⁸ joules of thermal energy. It’s nothing. When that droplet hits a substrate at 150°C, it loses 80% of that energy in 10⁻⁴ seconds.
Lawrence Livermore’s research documented the thermal gradient problem. At 5cm build height, surface temperature drops to 180°C. At 10cm, it’s below 100°C. Aluminum needs 300°C minimum for fusion without external energy input.
This thermal limitation also affects build speed. Liquid Metal Jetting systems must slow deposition rates as parts grow taller, allowing time for heat dissipation to prevent complete failure. Some systems implement ’cooling delays’ every few layers, extending build times unpredictably.
This is why Liquid Metal Jetting struggles with parts over 10cm tall. It’s not equipment limitations, it’s thermodynamics.
Related reading: Understanding why traditional Aluminum Additive Manufacturing faces similar thermal challenges across multiple technologies.
4. Why we developed continuous flow
Our Molten Metal Deposition technology emerged from a simple observation: if droplets are the problem, eliminate them.
In MMD, aluminum remains molten from wire to part. No flight time, or millions of oxide interfaces. No thermal gradient problems. The continuous stream maintains 660°C until deposition, carrying 50-100 times more thermal energy than individual droplets.
The results:
- 98% density vs LMJ’s reported 72% UTS
- Successful Al-7075 printing (impossible with droplet methods due to hot cracking)
- Build heights limited only by machine envelope, not thermal physics
- €12/kg wire cost vs €15-25/kg for LMJ systems
5. Process comparison: technical capabilities versus production requirements
| Manufacturing Factor | Liquid Metal Jetting | Molten Metal Deposition |
| Process complexity | Millions of discrete events requiring coordination | Single continuous stream with stable control |
| Temperature consistency | Droplet cooling during flight creates variations | Stable thermal conditions throughout deposition |
| Build height capability | Limited to ~10cm due to thermal gradients – upper layers too cold for fusion | Continuous heat supply enables unlimited height (machine envelope only) |
| Material properties | Statistical variations across droplet impacts | Uniform characteristics throughout part |
| Environmental sensitivity | High: air currents affect droplet trajectory | Low: continuous stream less sensitive to environment |
| Maintenance requirements | Regular nozzle cleaning and system calibration | Standard maintenance similar to CNC equipment |
| Quality predictability | Statistical outcomes with batch-to-batch variation | Consistent process outcomes with predictable results |
| High-strength alloy compatibility | Limited by rapid cooling (hot cracking in Al-7075) | Processing of Al-6061, Al-7075, and other industrial alloys |
| Production economics | High infrastructure and operating costs (€750-1000/kg) | Cost-effective with lower total costs (€250/kg) |
Note: For comparison with other aluminum AM technologies including Binder Jetting’s 40+ hour post-processing, see our complete technology analysis.
6. Liquid Metal Jetting’s application landscape
Liquid Metal Jetting excels in specific scenarios where its unique capabilities justify the complexity:
High-precision microcomponents: applications requiring sub-millimeter internal channels benefit from LMJ’s 50-micron droplet resolution. Medical devices, microfluidic systems, and precision hydraulic components represent ideal use cases where feature size directly impacts functionality.
Expeditionary manufacturing: the Navy’s shipboard deployment demonstrates LMJ’s value for remote operations. When traditional supply chains take weeks or months, the ability to print replacement parts on-site justifies any process limitations. The compact footprint of systems like the ElemX makes them deployable where larger equipment cannot go.
Material research and development: research institutions may benefit from LMJ’s ability to process small material quantities. New alloy development, parameter optimization studies, and proof-of-concept work can proceed with minimal material investment.
For high-volume production manufacturing, where repeatability, throughput, and economics drive decisions, the physics and cost structure favor continuous flow approaches like our Molten Metal Deposition technology.
7. Real production economics
Let’s examine actual costs. ADDiTEC states 200 cc/hour deposition rates for their ElemX. At their published wire cost of €15-25/kg, plus €150/hour machine time (typical for complex AM systems with vision monitoring), you’re looking at €750-1000/kg for deposited material.
Factor in the strength derating: if you only achieve 72% of material properties, you need 1.4x material for equivalent strength. Real cost exceeds €1,400/kg for functional parts.
Our current MMD systems match that 200 cc/hour, but with €12/kg wire and €50/hour machine costs (simpler system, no vision monitoring required). Total: €250/kg with full material properties. Our next generation, launching in 2025, achieves 500 cc/hour, 2.5x the throughput of Liquid Metal Jetting systems.
Build speed comparison for a 10x10x5cm part:
- Liquid Metal Jetting: 3-4 hours print time, plus 2-4 hours system calibration and setup
- Current MMD: 2.5 hours total (print and remove)
- Next-gen MMD: 1 hour total
Part turnaround comparison (from file to finished part):
- Liquid Metal Jetting: 8-12 hours including setup, calibration, and post-processing
- MMD: 2.5-4 hours from pressing start to finished part
For a 2kg aerospace bracket:
- Liquid Metal Jetting: €2,800 minimum
- Current MMD: €500
- Next-gen MMD: €200
Furthermore, the economics become even more compelling at scale.
8. The alloy advantage nobody discusses
Liquid Metal Jetting struggles with high-strength alloys. The published research on Al-6061 required extensive parameter optimization to achieve even partial success. Al-7075? Forget it. Specifically, the zinc content and rapid, uncontrolled cooling of individual droplets guarantee hot cracking.
We print Al-7075 routinely. The continuous melt pool maintains consistent temperature, enabling controlled solidification. No hot cracking. No parameter gymnastics. Just reliable parts with certified properties for aerospace applications.
9. Real customer results: Production economics in action
One application demonstrates why continuous flow beats droplets for production manufacturing: industrial cooling fans.
In practice, using MMD, we redesigned fan blades with optimized internal channels impossible to achieve with conventional manufacturing. Results: 10% efficiency improvement (75% vs 65% baseline), €45 per blade production cost versus €180 for 5-axis machined alternatives, currently producing 200+ blades monthly.
Liquid Metal Jetting could theoretically create similar geometries, but the 10cm height limitation would restrict blade size, and the production economics would push costs above traditional manufacturing. This is where physics and economics align in MMD’s favor.
For detailed thermal management applications, see our complete analysis of Liquid Aluminium Printing in production.
10. What Liquid Metal Jetting research reveals
Examining the patent history is instructive. Xerox filed 347 patents attempting to solve droplet consistency and oxidation.
- Patent US10,967,434: “Methods for reducing oxide formation.”
- Patent US11,014,163: “Droplet coalescence enhancement through oxide disruption.”
- Patent US11,235,384: “Electromagnetic stirring for oxide management.”
Ultimately, 347 attempts to solve fundamental physics problems. None succeeded completely.
In contrast, the research continues. MIT’s 2024 work on reactive atmospheres shows promise, adding hydrogen to reduce oxide formation. But you’re still fighting thermodynamics with every droplet.
Meanwhile, we’re printing production parts. Today. Without fighting physics.
11. The future of aluminum AM
Liquid Metal Jetting will find its niche. Military applications where any capability beats none. Research environments where 50-micron features matter more than economics. Specialized components where resolution justifies complexity.
For production manufacturing, the parts that keep industry running, continuous flow has already won. Not through marketing or patents, but through physics and economics.
Nevertheless, ADDiTEC will continue improving Liquid Metal Jetting. They’re talented engineers with significant backing. But they’re optimizing around fundamental limitations that continuous flow simply doesn’t have.
We chose to solve a different problem: how to make aluminum AM actually work for production. Not demonstrations. Not research papers. Production.
The results validate our choice every day.
Ready to move beyond droplets?
Whether you’re evaluating aluminum AM for production parts, research applications, or technology development, we can help you understand if continuous flow fits your needs.
We work with:
- Manufacturing companies seeking cost-effective aluminum AM
- Research institutions exploring new applications (ESA, defense research labs)
- OEMs developing next-generation thermal management solutions
Let’s discuss:
- Detailed cost analysis for your specific applications
- Material property data for your required alloys (including Al-7075)
- Production timelines and scalability
- Collaborative research opportunities
Contact our engineering team through info@valcun.be or visit our contact page.
Or visit our facility in Gent to see MMD in production and discuss your specific requirements.