1. Manufacturing of a 60 x 60 cm2 Gadolinium cathode with ultrasonic welding
Patrik Thuiner

2. Ultrasonic welding Principle Advantages
Ultrasonic generator
Principle
Ultrasonic acoustic vibrations + pressure
Molecules of one material diffuse into other material
Advantages
Joining of dissimilar materials
Low thermal impact on material
Precise and clean welds
Reproducible weld quality
Ultrasonic stack
Sonotrode
Nest

3. Ultrasonic welding Parts are placed onto the nest
Ultrasonic generator
Parts are placed onto the nest
Mechanical vibration is applied to the parts to be welded by sonotrode
Ultrasonic generator delivers high power AC signal with frequency matching resonance frequency of the ultrasonic stack
Electrical signal converted into mechanical vibration by converter
Amplitude of the vibration modified by booster
All three elements of the stack resonate at exactly the same ultrasonic frequency
Ultrasonic stack
Sonotrode
Nest

4. Ultrasonic welding Point or area welding Continuous welding
Sonotrode
Point or area welding
Different shapes and sizes of horn and anvil
Can be designed for our purposes, e.g. 0.5 x 10 cm2
Continuous welding
Sample moved between rotating sonotrode and anvil
Material needs to be quite robust
Not applicable to our case!
Nest
Sonotrode
Might be applicable to our samples!
Nest

5. Ultrasonic welding gadolinium? e.g. copper Surfaces interlock
Materials melt and flow together
e.g. lead
Surface interlocks break
Materials build lubricating film

6. Branson Ultrasonics R&D laboratory in Dietzenbach, D
Welding tests
Horn and anvil design
Quality assurance
(Possibly full assembly)
Smaller laboratory in Geneva, CH
Checking if tests can be conducted there
Tests might require one all-day visit!

7. Branson Ultrasonics R&D laboratory in Dietzenbach, D
for plastic welding!
R&D laboratory in Dietzenbach, D
Welding tests
Horn and anvil design
Quality assurance
(Possibly full assembly)
Smaller laboratory in Geneva, CH
Small test setup available
We spent half a day in Carouge!
for plastic welding!

8. Samples Gadolinium sheets Aluminium sheets Titanium sheets won’t work
25x25mm² area each
10 µm, 25 µm, and 50 µm thick
Aluminium sheets
1 mm thick
Provided by Branson
Titanium sheets won’t work

9. Setup Branson Ultraweld L20 Welding geometries Frequency Amplitudes
different combinations of sonotrode and anvil
Frequency
20 kHz only
Amplitudes
different amplitudes possible
we used e.g. 25 µm, 18 µm

10. Different combinations of sonotrode & anvil

11. Gd-Al-Al-Gd sandwich (to save some time...)
Sonotrode
Anvil
Sample

12. Gd-Al-Al-Gd sandwich (to save some time...)

13. Gd-Al-Al-Gd sandwich (to save some time...)
Gd-Al with 10 µm worked on top side of sample
Gd-Al
top
Gd-Gd
top
bottom

14. Gd-Al samples 10 µm Gd in Al sandwich worked
10 µm Gd on Al didn’t work
25 µm Gd on Al with different sonotrode and anvil didn’t work
Sonotrode punched through samples!

15. Summary (fortunately not the end of the story…)
Gd on Al works
with all sheets
for 20 kHz systems
with some of the sonotrodes and anvils available
Gd on Al doesn’t work
Gd on Gd doesn’t work
with the sonotrodes and anvils available
25 µm Gd

16. Branson Ultrasonics R&D laboratory in Dietzenbach, D
for plastic welding!
R&D laboratory in Dietzenbach, D
Welding tests
Horn and anvil design
Quality assurance
(Possibly full assembly)
Smaller laboratory in Geneva, CH
Small test setup available
We spent half a day in Carouge!
for plastic welding!
Didn’t go so well :(

17. Branson Ultrasonidos R&D laboratory in Barcelona, E
Specialised in metal welding
Machines with 20 kHz and 40 kHz
Point, area and continuous welding
Large stock of different sonotrodes and anvils
Planned stay for one or two days in end of June!
Tests still for free, but once it’s working…

18. Emerson a.s. … we need to talk with these ones about our budget.
Production and automation facilities in Nové Mesto nad Váhom, SK
Design and production of tooling for our specific needs!
Shape and size
Surface
Sonotrode length …

19. Acknowledgments
A huge thank you to José Rodrigues and Franck Didierjean of Branson Ultrasonics for the discussions and their support!