2. Ultrasonic Welding
Lesson Objectives
When you finish this lesson you will
understand:
• Ultrasonic Welding Definition,
Characteristics, Process & Applications
• Ultrasonic Power Generation
• Interfacial Interactions & Dissimilar
Metals Welding
Learning Activities
1. View Slides;
2. Read Notes,
3. Listen to lecture
4. Do on-line
workbook
Keywords: Ultrasonic Welding, Transducer, Sonotrode, Anvil
3. Ultrasonic Welding Process
• Components of
ultrasonic
welding system
include:
– Transducer
– Sonotrode
– Anvil Anvil
Mass
Sonotrode
tip
Clamping
force
wedge Transducer
Force
WeldmentVibration
4. • Clamping force
• Welding time
• Trigger Point
• Frequency
• Linear Vibration Amplitude
• Welding Tools
• Ultrasonic Power
Ultrasonic Welding Variables
5. Ultrasonic Welding Power
Generation
• Electrical power of 60
Hz is supplied to the
frequency converter.
• The frequency
converter converts the
required 60 Hz signal
to the welding
frequency (from 10 to
75 kHz).
Electrical
energy
Frequency
converter
Vibratory
transducer
Transducer
7. • Frequency is transformed to
vibration energy through the
transducer.
• Energy requirement established
through the following empirical
relationship.
– E = K (HT)3/2
– E = electrical energy, W*s (J)
– H = Vickers hardness number
– T = thickness of the sheet
Electrical
energy
Frequency
Converter
Vibratory
transducer
Ultrasonic Welding Power
Generation
11. Sonotrode Tip and Anvil Material
High Speed Tool Steels used to weld
• Soft Materials
• Aluminum
• Copper
• Iron
• Low Carbon Steel
Hardenable Nickel-Base Alloys used to weld
• Hard, High Strength Metals and Alloys
12. • Localized temperature rises resulting from
interfacial slip and plastic deformation.
• Temperature is also influenced by power,
clamping force, and thermal properties of
the material.
• Localized Plastic Deformation
• Metallurgical phenomena such as
recrystallizing, phase transformation, etc.
can occur.
Ultrasonic Welding Interfacial
Interaction
14. Extreme Interpenetration
Nickel Foil (top) to Gold-Plated Kovar Foil
Local Plastic Flow
Dark Regions are Trapped Oxide
Nickel Foil (top) to Molybdenum Sheet
Very Little Penetration, Thin
Bond Line, Fiber Flow
Molybdenum Sheet to Itself
AWS Welding Handbook
16. • No heat is applied and no melting occurs
• Permits welding of thin to thick sections
• Welding can be made through some surface
coatings
• Dissimilar metals having vastly different
melting points can be joined
• Pressures used are lower, welding times are
shorter, and the thickness of deformed regions
are thinner than for cold welding
Advantages of Ultrasonic
Welding
17. • The thickness of the component adjacent to the
sonotrode tip is restricted because of power
limitations of the equipment.
• Process is limited to lap joints.
• Butt welds can not be made because there is no
means of supporting the work pieces and
applying clamping force.
• Due to fatigue loading the life of equipment is
short.
Limitations of Ultrasonic
Welding
18. Ultrasonic Welding of Plastics
• Advantages
– Fast
– Can spot or seam weld
• Limitations
– Equipment complex,
many variables
– Only use on small parts
– Cannot weld all plastics
0.1.1.2.5.T25.95.12
19. • Assembling of electronic components such
as diodes and semiconductors with
substrates
• Electrical connections to current carrying
devices including motors, field coils, and
capacitors
• Encapsulation and packaging
• Plastic parts
• Fabricating nuclear fuel elements
• In aircraft structural applications.
Applications of Ultrasonic
Welding