Joining Technology - 230406 Flashcards
Ultrasonic welding
Ceramics to glass, copper
Joining technology
Adhesive bond – welding –
** pressure welding (ultrasonic and friction) &
** fusion welding (tig, mag, electron beam, laser beam)
Ultrasonic welding parts
Sonotrode, join parts and the welding will be generated between both parts, anvil
Describe the ultrasonic welding process
- 30-100 microns of motion, force parallel to the surfaces.
- Parts are fixed one against the other, ultrasonic horn or sonotrode is applied to the top part, vertical high frequency vibration, holding stage,
- 90% are plastic welding (perpendicular to the surface) and 10% are metal welding.
- Only amorphous polymers work, semi-crystalline materials only join with itself.
Appllications in plastic welding
embedding of meta inserts in plastics, avoids the fracture of the material by doing micro movements
Material of sonotrode
Sonotrode/Horn: Powder metal, strong materials against crack and fatigue behavior.
2000 euros for a tool.
Micro view of the process
Fracturing of the oxide coatings, until adhesion of the atomic lattice forces. Ideal strength since it’s the same strength as mateial.
weldable metals
99%: copper, aluminum. steel is too hard sonotrodes would wear easily. Compacting copper wires, to weld them together or with another material.
Not plastic flow or extrusion, not a very big separation between the wires, an ideal range must be kept.
Applications of metal US welding
Medical devices, no chemical adhesives, torsion metal process. Medical containers.
US metal welding advantages
Advantages: different melt temperatures materials, no additional material, low heat affected parts.
US metal welding disadvantages
Disadvantages: Cracks can occur (fatigue effect can happen), thickness is limited, 1 or 2 mm thickness no more, welding can happen between the sonotrode and the material.
