Dan King, Fabrisonic

(Approved for public release; distribution is unlimited.)

            Fabrisonic has become known for 3D printing unique features in the additive manufacturing (AM) space due to its use of Ultrasonic Additive Manufacturing (UAM).  The process’s key benefits include combining dissimilar metals, creating parts with complex internal geometries, and embedding sensors into solid metal parts. Recently, Fabrisonic has taken this technology a step further by incorporating all three features while adding organic geometry created via another metal AM process, Powder Bed Fusion (PBF).

Finished Part Made through combining Ultrasonic Additive Manufacturing and Powder Bed Fusion

It is important to understand the PBF process before getting into the intricacies of combining it with UAM. Powder bed involves depositing a layer of metal in powder form over a build plate. In most cases, a laser then melts a cross-section out of this powder. New powder is then deposited, and this process is repeated layer by layer until the final geometry is achieved [1].

Fabrisonic has been active in combining multiple AM processes to produce the best part possible.  Just as a traditional machine shop may have CNC milling machines, grinding machines, and lathes, it is likely that the manufacturer of the future will also host multiple complimentary AM systems.  UAM is well suited to printing large components with multiple metals, embedded sensors, and internal structure.  However, due to the large forces need to create a bond, UAM is not optimal for fine organic structures.  Alternatively, PBF is well suited for making these delicate organic patterns but is challenged on overall part size.  

Recently, Fabrisonic has leveraged PBF to create fine organic patterns that are embedded by UAM into large structures.   By combining the strengths of both processes, Fabrisonic can provide the exact solution needed by the customer. Most fusion-based AM processes would have trouble printing dissimilar metals on a powder bed part. However, UAM is different as it can accommodate a wide array of external conditions. If there is a smooth, metal substrate then UAM can be used.  In past work, UAM has been utilized to embed PBF elements or to add more material to a free-standing PBF component.

For this project, the customer was looking for:

  • An organic stainless steel geometry
  • Dissimilar metal transition
  • Embedded sensors fully encapsulated in metal

The organic structure was obviously best suited for PBF, and Fabrisonic partnered with EWI to produce the base structure.   The PBF components arrived at Fabrisonic as rough blanks.  These were placed in a fixture to constrain the part for welding. This is an essential step, as vibrations produced during UAM will cause the substrate to move quite a bit if not properly held in place. The subtractive portion of UAM was then implemented by milling the top of the part to a flat, even surface. Layers of aluminum and copper sheet were then printed layer-by-layer onto the top surface. This combining of dissimilar metals to one another is something many AM processes cannot achieve but is a feature in which Fabrisonic specializes.

      

     Part placed in Fixture          Aluminum Layer                    Copper Layer

Once dissimilar metals were printed to the designated height, the part was milled to create a pocket for a custom sensor. The sensor was placed into this pocket and UAM was used to add additional layers of copper and/or aluminum. By printing over this pocket, the sensor was encapsulated in the part and protected by the hermetic seal produced by the additional layers bonding to the surrounding metal. This improves the accuracy of the sensor’s readings as it is located at the exact location the customer needs information.  At the same time, the seal enhances the life of the sensor. Once printed to the requested height, the excess foil was milled to the final shape.  

   
Sensor Embedded into Metal    Cleaned Up Part

The part and process shown were the first of many to include both UAM and an alternative form of AM. As Fabrisonic receives more opportunities to incorporate this unique technology into new applications, the products manufactured will only continue to advance. By combining the benefits of other forms of additive with the numerous benefits of UAM, different processes will begin to complement each other. Who knows what boundaries engineers and designers will push next?

To learn more about Fabrisonic and how our technologies can enable your engineering designs, visit Fabrisonic.com, and check out all the exciting innovations achieved in the past!

Sources:

[1] https://www.lboro.ac.uk/research/amrg/about/the7categoriesofadditivemanufacturing/powderbedfusion/

[2] https://www.insidemetaladditivemanufacturing.com/blog/operability-functionality-and-maintenance-of-lb-pbfam

(Approved for public release; distribution is unlimited.)


Leave a Reply

Your email address will not be published.