Ultrasonic depowdering: A new tool in the industrial powder removal toolbox
Learn why ultrasonic depowdering can be a game-changer and when the excitation form is the right choice for your application.
KONTAKT
MARKETING@SOLUKON.DETHE PRINCIPLES FOR AUTOMATED DEPOWDERING:
Automated depowdering is a relatively new discipline in additive manufacturing and still: since Solukon was founded and the world’s first depowdering system, the SFM-AT800-S, was launched in 2015, a number of successful principles have become established on the market. The most important of these include:
1. Depowdering must take place in a protected atmosphere
Health risks from fine dust and the danger of explosions are effectively controlled only when using a sealed process chamber. For reactive materials, the process chamber is inerted with a protective gas.
2. Depowdering must be reproducible
This means achieving consistent cleaning results for identical components (i.e., repeatability). What may sound obvious or like a no-brainer is actually a standard that can only truly be maintained with automated powder removal using Solukon.
3. The best cleaning result is achieved through the combination of rotation and vibration excitation
(Endless) rotation around two axes and targeted vibration excitation make the adhering powder flowable within internal channels. The excitation intensity of the vibrator can be adjusted in Solukon’s powder removal systems. However, how the pneumatically generated vibrations actually act on the part is highly individual and depends on the geometry of the component. What matters is the result: the powder behaves like a liquid and flows out of internal channels. Powder clumps are broken up by a high-frequency knocker, which can also be activated when needed.
Until recently, the combination of a pneumatic vibrator and a knocker to stimulate vibration would have been on this list of basic principles for depowdering. This is because pneumatic vibrators are reliable, cost-effective and highly efficient. However, they consume large amounts of compressed air and are difficult to control, which can lead to problems with sensitive parts. This is because exceeding the resonance frequency could damage the parts in sensitive structures.
SFM-AT350-E with ultrasonics
With the introduction of the E version of the SFM-AT350 depowdering system, Solukon has therefore expanded the toolbox of excitations and brought a system with ultrasonic excitation onto the market. The SFM-AT350-E depowders components up to 400 x 400 x 400 mm and 100 kg fully automatically with programmable 2-axis rotation and frequency excitation in the ultrasonic range.
What can ultrasonic excitation do, and what are its key advantages?
In the SFM-AT350-E, the component is excited at ultrasonic frequencies using a piezoelectric system. The excitation is applied directly at the turntable of the automated depowdering system, allowing the component to be brought effortlessly and precisely into an optimal vibration state. What makes this approach unique is that instead of using a fixed frequency, the system continuously and rapidly sweeps through a specific frequency range in which cleaning is particularly effective. This sweeping ensures highly reliable cleaning by utilizing well-defined frequencies within the ultrasonic range.
The ultra-high frequencies used for electrical excitation are well above the component’s potentially damaging natural resonance frequency. This prevents the component from resonating and eliminates the risk of structural damage. As a result, ultrasonic depowdering is an especially gentle form of cleaning.
Another advantage: ultrasonic excitation is completely silent. This allows the
SFM-AT350-E to be installed even outside noisy, high-throughput production environments.
When is ultrasound the appropriate form of excitation?
As with many challenges related to powder removal, choosing between pneumatic and ultrasonic excitation largely depends on the specific application and the geometry of the component. Both methods can deliver effective cleaning results. However, ultrasound is often the preferred option for parts with extremely delicate features or fragile support structures, as it avoids the oscillations typically associated with pneumatic excitation—greatly reducing the risk of component damage from vibrational stress. Even very fine structures (typically less than 0.5 mm in diameter) respond exceptionally well to high-frequency ultrasonic excitation.
In addition, powder can become clogged in narrow and deep channels if the excitation is not applied correctly. Ultrasonic excitation is capable of reliably cleaning such channels and can even dislodge existing blockages. The following comparative test conducted by a Solukon customer highlights the advantages of ultrasonic technology in cleaning narrow and long channels:
What specific use cases are there?
Swissm4m: Depowdering of medical parts
The SFM-AT350-E has proven to be an ideal system for the medical industry in particular. Typical applications here are hip cups, which have a grid-like structure on the surface. Such acetabular cups, together with spinal inserts and dental tools, were part of a build job at the Swiss m4m Center, a technology transfer center for the medical and dental industry.
It took just 7.5 minutes to clean the stainless-steel medical components in the SFM-AT350-E with ultrasonic excitation.
The Exploration Company: Depowdering of a Thruster Combustion Chamber of a rocket engine
The ultrasonic technology of the SFM-AT350-E has also already proven itself in the aerospace industry, where particularly high demands are placed on industrial depowdering. International aerospace company “The Exploration Company” relies on ultrasonic excitation with the SFM-AT350-E from Solukon for the depowdering of rocket parts.
This combustion chamber made of Inconel (IN718) weighs around 15 kg, is around 370 mm high and has a highly complex interior: the intricate channels are up to 400 mm long, and the smallest diameter of these channels is 1.5 mm.
With the SFM-AT350-E, the team led by Senior Additive Manufacturing Engineer Maxi Strixner was able to clean the component comfortably, gently and silently. For the targeted cleaning of the rocket combustion chamber, the team ran a cleaning program specially written for the component. After 30 minutes, the component was successfully cleaned.
For the Exploration Company, the silent cleaning and the reliable cleaning quality are the main reasons why they chose the SFM-AT350-E from Solukon:
„The Solukon ultrasonic depowdering system has been a game-changer for our small workshop. Its quiet design means we can run it right next to our workspace without any disruption — which is a big plus. When used with a program, the system drastically cuts down on manual labor, and delivers consistent, clean results. All of this translates into real time and cost savings, making the investment absolutely worthwhile”, says Boris Schaff, Additive Manufacturing Engineer at The Exploration Company.
Ultrasonic technology as a new tool in the powder removal toolbox
As the examples show, the ultrasonic technology of the SFM-AT350-E has already proven itself on the market. And still: the E-version is by no means a replacement for the SFM-AT350’s standard depowdering technology with pneumatic excitation. Ultrasonic excitation is rather an additional tool in the toolbox of automated depowdering.
