Northwestern University & Argonne National Laboratory Examine Directed Energy Deposition by X-Ray
While the structures produced through 3D printing can be fascinating, tangible, and extremely inspiring—not to mention actually useful—you may still find the operational processes behind the technology to be a little intimidating as it often seems the impossible is being fulfilled with a bit of filament, software, and hardware that may not even be that expensive. You may also find it surprising to know that even researchers extremely accustomed with 3D printing may still be in the dark about what happens during some of the internal processes too, especially in using laser/powder combinations.
To take a closer look, a research team combining forces from both Northwestern University and Argonne National Laboratory began examining exactly what happens during 3D printing rather than after, publishing their findings in ‘In-situ high-speed X-ray imaging of piezo-driven directed energy deposition additive manufacturing.’ Authors Sarah J. Wolff, Hao Wu, Niranjan Parab, Cang Zhao, Kornel F. Ehmann, Tao Sun, and Jian Cao point out that historically it has been challenging to monitor the internal processes in minute detail because any interruption of the process can be detrimental to the end product. And while we have followed many different instances of researchers analyzing 3D printing and unique materials, along with working to find improved strategies in AM, this study definitely has a different focus:
Directed energy deposition relies on heated powder particles, melted to create the layers of a structure. This method of fabrication has been growing in popularity, especially in rapid prototyping and parts maintenance. Benefits include faster and better solidification of printed objects, along with flexibility in types and use of materials.
Although piezo-electrics may be a term new to many, it involves the release of a charge when under pressure or other exertion. We followed a study regarding piezoelectric materials earlier this year, in regards to their potential in 3D printing for developing a variety of different sensors and smart materials. In this more recent study, the researchers are interested in studying piezo-directed energy with X-rays to understand more about how lasers and powder interact during 3D printing.
For this experiment, the team designed a sealed chamber, encompassing the piezo-driven system and required argon gas.
Piezo vibration causes the powder to flow into the area where both the laser and X-ray beams line up. Specific parameters were set up for controlling the flow rate by controlling the frequency and power of piezo vibration. Any porosity was tracked and evaluated, along with spattering and associated particle ejection. The ultimate hope in performing such imaging experiments was to understand more about DED processes and the materials involved.
The researchers point out that most sensors are not capable of providing enough data, and do not possess the resolution necessary to show DED rapid cooling processes. In this study, they were able to pinpoint some of the reasons behind porosity but point out that more research is needed to understand particle entrainment.
Find out more about the materials and custom system used for testing here.
What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.
[Source / Images:In-situ high-speed X-ray imaging of piezo-driven directed energy deposition additive manufacturing
via 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing https://3dprint.com
February 11, 2019 at 01:24AM