Fabrisonic's Patented 3D Printed Process Enables Unique Heat Exchanger Development

Bringing 'Impossible' Heat Exchanger Designs to Life

Fabrisonic utilizes Ultrasonic Additive Manufacturing (UAM), a patented technology which harnesses sound waves to merge layers of metal foil in a process that requires no melting. The 3D metal printing process creates complex components that have unique features not possible with traditional manufacturing techniques.

Our Ultrasonic Additive Manufacturing Process Is Different:

  • UAM can create complex three dimensional flow paths where every external and internal surface has CNC quality finish.
  • Fabrisonic SonicLayer series of metal printers are hybrid systems with both additive and subtractive processes.  Since all steps happen in one machine with one set of datums, tolerances are improved as a single machine avoids moving a part from machine to machine.  
  • The solid state nature of the welding process allows printing any metal, anywhere in the part.  Combining a dissimilar metal such as a layer or copper in an aluminum can help wick away heat, increase performance and decrease weight.

Read on to learn more about the unique capabilities Ultrasonic Additive Manufacturing has in the heat exchanger space. 

Lightweighting

Dissimilar Metal 3D Printing Reduces Weight

Copper is an advantageous metal to use for heat exchangers because it has twice the thermal conductivity of aluminum. However, copper is three times denser than aluminum, so it poses a weight trade-off in-flight applications. A distinct benefit of UAM in comparison to other technologies commonly used to manufacturer heat exchangers is that Fabrisonic can selectively print copper in high heat flux areas where it is needed and then print the rest of the part out of aluminum to save on material cost and reduce weight.

Printing copper in high heat flux regions leverages its ability to quickly wick heat away. However, printing surrounding structure out of aluminum takes advantage of its lightweight and high strength properties.  UAM can print most metals, and due to the low temperature of the welding process, dissimilar metals can be welded at will without concern for unwanted metallurgical interactions.

Our process specializes in dissimilar metals. Changing materials on the fly is quite challenging, if not impossible, in other additive processes. However, because UAM is a low-temperature process where the metals stay below 250F when printing, and the materials are off-the-shelf foils, we can simply change out our material feedstock, adjust our welding parameters, and we can be printing an entirely different metal in minutes!

Distinct lightweighting advantages of UAM:

  • Protects material properties of the incoming feedstock – Since the materials are only slightly heated, the materials do not experience changes in grain size, precipitation reactions, nor phase changes. The properties of the incoming feedstock are the same as the properties of the final part.
  • Creates bonds between dissimilar metals without creating an undesirable brittle metallurgy – This capability differentiates UAM from fusion based processes and enables Fabrisonic to print engineered materials with custom material properties or properties to match an existing component. For instance, layers of Molybdenum and Invar can be printed into an aluminum heat exchanger to match the CTE of a mounted electronic circuit.

Embedding Electronics into Solid Metal

Wires, fibers, sensors and more into 100% dense metal

The solid-state nature of Fabrisonic’s UAM bond allows for encapsulation of all manner of wires, fibers, and sensors into a metallic substrate. Since the metals do not have to be heated for bonding, electronics can be embedded without damage. This enables sensors, communication circuits, and actuators to be embedded into fully dense metallic structures for lasting security and reliability.  For thermal devices, this means engineers can have thermal data at any point they want in a 3D printed part.

Sensors and electrical controls are an essential part of every industry. A common problem is the degradation of the exposed control elements from both corrosion and wear. Ideally, in such situations, it would be best to bury the electronics in solid metal to protect them. This isn’t possible with conventional manufacturing technologies so most companies resort to complicated seals that also degrade over time. Conventional processes such as casting and welding can occasionally create a protective structure, but these high temperature processes typically damage the exact components they are trying to protect.

Fabrisonic’s UAM process can eliminate these common issues to create lasting protection solutions including:

  • Higher protection- A common problem with sensors operating in harsh environments is degradation from radiation exposure, corrosion, impact, wear, and so on. Ideally, it would be best to bury the sensors in a solid metal substrate for protection. However, this is often difficult using conventional manufacturing technologies due to complications in sealing and elevated processing temperatures.
  • Higher performance- Most sensors in use today are attached to the periphery of equipment, limiting signal strength and response times. Embedding sensors in metal allows the sensors to be placed at the ideal location for measurement and control, leading to higher performing products.  The signal wires can be embedded along the shortest path through the part improving signal strength and reliability.
  • Design freedom-  Metal 3D printing is changing the design paradigm of products from cell phones to jet engines. Low-temperature metal 3D printing enables electronics and requisite wiring to be placed anywhere in a structure. As the part is grown in the printer, wiring can be placed through circuitous routes throughout the center of a large structure. This gives designer freedom to locate structure, sensors, and wiring at the optimal location for function; not the optimal location for construction.

Distinct Advantages of Using UAM vs. CNC Milling for Heat Exchangers

Brazed assemblies not working for your heat exchanger?

Historically, specialty heat exchangers have been made using traditional CNC machining to create planar arrays of cross-drilled holes. This limits the shape of the internal passageway to straight, planar channels.  3D printing now allows internal geometries to be fully optimized for localized thermal performance with varied shapes and complex 3D flow paths.

Using conventional manufacturing, if a designer needs to go beyond straight planar channels, complex shapes are made using a series of connected machined components joined via brazing or diffusion bonding. However, these additional steps are expensive, time-consuming, and undesirable on the production level. 3D printing removes all connections allowing for uniform thermal expansion and elimination of problematic joints.

Even with advanced methods such as brazing, air gap, material selection, and channel sizes can never be fully optimized. Metal 3D printing allows designers to optimize thermal performance with ‘impossible designs’ by removing traditional manufacturing geometry constraints. Channel cross section and unique flow elements can be easily integrated into a 3D printed heat exchanger.  Multiple metals can easily be printed in the same part during one print job.

Space-Grade Heat Exchangers

Fabrisonic Meets NASA JPL 6 Qualifications

Fabrisonic’s patented low-temperature 3D metal printing process, Ultrasonic Additive Manufacturing (UAM), is an enabling technology that allows engineers to print otherwise impossible heat exchangers. With UAM, designers can achieve dissimilar metals anywhere in the device, CNC surface finishes on both the exterior and interior surfaces, as well as the ability to embed sensors at any location in a given geometry. 

Fabrisonic has gotten closer to seeing its heat exchangers launched into space. Recently, Fabrisonic heat exchangers passed stringent NASA JPL qualification tests. You can read more in  ‘Space-grade 3D Metal Printed Heat Exchangers‘, a recently published technical paper by Justin Wenning, Production Engineer at Fabrisonic.

Fabrisonic's patented metal 3D printing process, Ultrasonic Additive Manufacturing (UAM), enables joining alloys that have historically been difficult to weld including:

  • 1000, 2000, 6000, and 7000 series aluminums
  • Coppers
  • Stainless steels
  • Exotic refractory metals,
“Traditional manufacturing may have a few decade head start on producing heat exchangers, but UAM is on track as a revolutionary new way of designing and producing high-performance heat exchangers like mechanically pumped fluid loops and heat pipes.”
Justin Wenning

Justin Wenning-- Product Engineer Fabrisonic LLC.

When you tell a thermal engineer that they create a device that is lighter, more efficient, and fits into a smaller space, they call you a liar...and then they start asking a bunch of questions.

Mark Norfolk

Mark Norfolk-- President and CEO Fabrisonic LLC.

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