ultrasonic welding
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ULTRASONIC WELDING
SUBMITTED BY-SHUBHANGI OJHA
ME-3RD YEAR
CONTENTSBRIEF HISTORYINTRODUCTIONCLASSIFICATIONMECHANISMPROCESS VARIABLESADVANTAGESLIMITATIONSAPPLICATIONS
BRIEF HISTORY Ultrasonic welding was first developed in the
1940’s. But it was used industrially in 1960’s. In 1960 Sonobond Ultrasonics,originally
known as Aeroprojects, Incorporated, developed the first metal ultrasonic welding machine to be awarded a United States Patent.
In 1963 it was introduced into the plastic welding process and it has since been the most popular welding method.
INTRODUCTION What is welding?
What are ultrasonic waves?
What is ultrasonic welding?
WHAT IS ULTRASONIC WELDING?A solid state welding process.
Wherein high-frequency ultrasonic vibrations are locally applied to workpieces being held together under pressure.
Which results in coalescence between the two pieces to be joined.
CLASSIFICATION OF ULTRASONIC
WELDINGMETAL WELDING
PLASTIC WELDING
Mainly non-ferrous metals and alloys.
Aluminium,copper,nickel,molybednum etc.
Precious metals like platinum,gold,silver etc.
ThermoplasticsAmorphous as
well as crystalline.
ULTRASONIC WELDING
COMPONENTSComponents of ultrasonic welding system include:Power supply-sonic
generatorTransducerBoosterSonotrode or HornAnvilPneumatic system
ULTRASONIC WELDING
MECHANISM(METALS) A static clamping force
is applied perpendicular to the interface between the work pieces.
The contacting sonotrode oscillates parallel to the interface.
Combined effect of static and oscillating force produces deformation which promotes welding.
ULTRASONIC WELDING MECHANISM(PLASTICS)
One of the materials usually has a spiked energy director which contacts the second plastic part
Horn moves to and fro vertically.
ultrasonic energy melts the point contact between the parts, creating a joint.
ULTRASONIC WELDING
MECHANISM(PLASTICS)
ULTRASONIC WELDING
VARIABLESUltrasonic powerClamping forceWelding time Frequency Linear Vibration Amplitude
ULTRASONIC WELDING POWER GENERATION
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 H = Vickers hardness
number T = thickness of the
sheet
ADVANTAGESNo heat is applied and no melting
occurs(METALS)No fumes or odour.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.
No filler metal is used.Energy efficiency, high productivity with low
costs.
LIMITATIONSThe thickness of the component
adjacent to the sonotrode tip must not exceed relatively thin gages 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 workpieces and applying clamping force.
APPLICATIONSAssembling 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
APPLICATIONSAppliance: steam iron, pump housing,
vacuum cleaner wand, and dishwasher spray arm.
Automotive: lenses, filters,valves,glove box door, instrument cluster, air diverter and mass airflow sensor.
Electrical: terminal blocks, connectors, switches.
Medical: arterial filter, cardiometry reservoir, blood/gas filter, face mask and IV spike/filter.
CONCLUSION In conclusion ultrasonic welding has many
advantages over other welding techniques for many type e of connections. These include speed, cost, reliability and many others. However, it should also be made clear that it is only ideal for a relatively small proportion of all of the possible joints. Ultrasonic welding should not be seen as a replacement for other techniques, such as GTAW, resistance, laser etc; but rather as an option in situations for which it is well situated.
BIBLIOGRAPHYO.P. Khanna “WELDING
TECHNOLOGY”.Staple ultrasonic corporation
“Principles and applications of high grade bonding technology”.
Richard L Little “WELDING AND WELDING TECHNOLOGY”.
Internet.
THANK YOU
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