Temperature measurement in FSW operations
The welding temperature is an essential parameter for the quality control of welding. A too hot weld can result in a nugget collapse or reduction of mechanical properties. On the contrary, a too cold weld may cause poor stirring or wormhole.
Now you can control the temperature of your weld to ensure its quality thanks to the Stirweld solution: the smart FSW tool holder.

SMART TOOL HOLDER FOR TEMPERATURE MEASUREMENT
WELD TEMPERATURE MEASUREMENT
From 20 to 1000°C,
2 temperature sensors
NO BATTERY
For 24/7 availability: powered by wire connections
NUMERICAL OUTPUT (NO RADIO, NO BLUETOOTH)
Use of numerical output to avoid any signal perturbation
QUALITY CONTROL
Quality control at 100%
COMPATIBILITY
Compatible with all existing FSW machines
ONLINE RECORDING
Online tool temperature during FSW
Automatical record

WHY IS THE TEMPERATURE MEASUREMENT ESSENTIAL IN FSW?
Friction stir welding is a cold-welding technique, i.e., it does not reach the melting point of the material. The welding temperature is therefore essential for a defect-free quality weld.
If an FSW weld is too hot, it can lead to weld defects such as nugget collapses or reduced mechanical properties. If the weld is too cold, poor stirring, or wormholes can occur.
Therefore, measuring the welding temperature allows you to quality control 100% of your welds while dividing by 5 your non-destructive control tests.
Comparison between hot weld, cold weld & defect free weld

For hot welds, the maximum temperature does not exceed the melting temperature. In this case, the melting temperature is equal to 555°C.
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Which parameters affect the welding temperature?
The weld temperature depends on rotational speed and welding speed. Below we will see the impact if the weld is too hot, too cold and how we can reach defect free weld.
The material is brought to a 400°C temperature thanks to the FSW tool.
PHENOMENA 1: Heating by the tool friction on the material.
PHENOMENA 2: Material flow due to the tool stirring.

What happens when the temperature rises or falls? What is the impact on the FSW weld quality?
WHEN THE TEMPERATURE INCREASES
The rotational speed is high & the welding speed is low

HOT WELD
Porosities are in the top of the weld
QUALITY CONTROL WELDS
Maximum temperature does not exceed the melting temperature

DEFECT FREE WELD
There is no porosity
WHEN THE TEMPERATURE DECREASES
The rotational speed is low & the welding speed is high

COLD WELD
Porosities are in the bottom of the weld
TEMPERATURE MAPPING

As we can see on the graph, having a defect-free weld depends first of all on the correct welding parameters: rotation speed, welding speed, tool geometry, force control.
Indeed, all these parameters will influence the quality of the weld because the more friction you use, the more you heat and the faster you weld, the less you heat. It is therefore necessary to find the right balance between both.
Without this temperature control…
Insufficient temperature would make it difficult to mix the parts, creating poor stirring or wormholes.
Too high temperature, approaching the melting point of the welded material, could lead to nugget collapse or reducing mechanical properties.
With this temperature control…
Quality control process: temperature control results in quality welds and therefore dividing by 5 the non-destructive control tests (bend test, leak test…).
STIRWELD SMART TOOL HOLDER BENEFITS




ONLINE TEMPERATURE MEASUREMENT
For severe FSW components: space, aerospace, automotive applications
QUALITY CONTROL
100% quality control of FSW parts: compatible with EN 9100 standard
OPTIMIZATION OF WELDING PARAMETERS
Increase of welding speed: from 20 to 200%
STIRWELD EXPERTISE
Expertise on FSW and on tool-workpiece FSW abacus

TECHNICAL SHEET
Temperature measurement
2 temperature measurements into the FSW tool:
Accuracy: +/-2°C
Full wire system (no radio, no Wi-Fi, no Bluetooth)
Numercial outputs
Compatible with all existing machines
Compatible with fix pin and retractable pin
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ZOOM ON STIRWELD FSW TOOL
In addition to provide you a temperature measurement tool holder, Stirweld also offers you a range of FSW tools.
This range of tools is adaptable according to your needs: temperature measurement, fixed pin or retractable pin.
Our tools are standardised and can be adapted to any FSW equipments.
And finally, thanks to Stirweld’s FSW expertise, we have developed tools to weld different materials: cast aluminium, high strength aluminium, copper, steel with aluminium.
Want to know more about our tools? Download our catalogue!
SMART TOOL HOLDER APPLICATIONS
Application 1: quality control during manufacturing
Repeatable temperature equals to repeatable quality
Application 2: optimization of welding speed
Optimization of welding speed according to optimum process temperature.
Application 3: optimization of RPM parameter as function of part geometry
Less material means higher temperature and require lower RPM
Do you want to add temperature measurement to your FSW equipment?
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