Technology

FSW advantages:
  • Few consumables, no material input, no surface preparation, no shielding gas
  • Welding of all aluminium alloys (1xxx, 2xxx, 4xxx, 5xxx, 6xxx, 7xxx)
  • Al-Si: easy welding of aluminium foundry, including die casting
  • High mechanical resistance close to the base material
  • No leakage: water, acid, or air
  • Excellent thermal and electrical conduction.
  • Solution to the shortage of qualified welders.
  • Cold welding: minimal distortion of welded parts
  • Already democratize in aeronautics, automotive, space, railway and naval sectors
  • Existing welding standard: ISO 25239

In 1995, a new welding technique is invented by The Welding Institute (TWI): Friction Stir Welding (FSW).  

Since 2015, the TWI patent falls in the public domain, opening great opportunities for the development of FSW technology.

FSW Principle:

Step 1: The FSW tool consists in a shoulder to heat the material by friction and a pin to stir the parts together.

Description de l'outil FSW

Step 2: The parts are clamped either edge to edge (butt welding) or by overlapping (lap welding).

Step 3: The tool is rotated (speed from 400 to 1800 rpm) and then dips vertically into the material.

Step 4: After a temperature stabilization phase (between 1 to 5 seconds), the tool moves along the weld seam (constant speed of 200 to 3000 mm / min depending on the nature and thickness of the components).

Step 5: During movement, a controlled force (3 kN to 18 kN) is applied on the FSW tool. The heat generated by the friction makes the material softer and the tool stirs the parts together. The welding operation is carried out in a solid state without material fusion.

Butt weld

Transparency welding

Step 6: At the end of the weld, the tool rises vertically leaving a hole. This hole is often seen as a defect; however, many solutions exist to solve this drawback.

You will also find very interesting information on the Wikipedia page of FSW.

Mature technology for assembly of aluminum and copper.
Welding of high-strength aluminum alloys: 2000, 6000 and 7000
Without fusion and without material input
Welding of dissimilar materials: Al-Cu, Al-Fe, foundry
"Green" process: no cleaning before welding, no shielding gas, no fume, no noise

Cost Benefits:

  • Low welding cost: few consumables (1 tool = welding of 1500-m long), no material input, no surface preparation, no shielding gas, no gas equipment, low power consumption : 0,2 kWh/m (50% of MIG welding)
  • Reduction of post-welding inspection
  • Welding is carried out in a NC machine tool limiting investment
  • Possible rental of the FSW head to limit the investment

Advantages on goods:

  • Welding of all aluminium alloys (1xxx, 2xxx, 4xxx, 5xxx, 6xxx, 7xxx)
  • Al-Si: easy welding of aluminium foundry, including die casting
  • High mechanical resistance: weld efficiency of 80-90%, fatigue strength close to the base material
  • No leakage: water, acid, or air
  • Excellent thermal and electrical conduction.
  • Forming after welding: stamping or bending of welded parts are possible without cracking
  • Welding capacity up to 20 mm

Process advantages:

  • Solution to the shortage of qualified welders.
  • No surface preparation: no cleaning or grinding is required
  • The weld is invisible on the back side and requires a small machining on the welding side to remove it if necessary.
  • Replacement of brazing, TIG, MIG or FE welding.
  • Cold welding (temperature of 400°C): minimal distortion of welded parts, small heat affected zones (HAZ).
  • No spar, no smoke.
  • Non-toxic: no ozone production compared to arc welding
  • Welding possible in all positions: no molten pool

Customer benefits:

  • Already democratize in aeronautics, automotive, space, railway and naval sectors
  • Existing welding standard: ISO 25239
StirWeld aims to democratize the FSW by:
The drastic reduction of the investment cost
A catalog of quality and low cost FSW tools
Support of our experts throughout your industrialization cycle

Since 1995, FSW remains a technology reserved for high added value applications involving expensive equipment. StirWeld invention uses a NC machine tool for FSW.

This innovation reduces drastically the investment cost to access to FSW while offering performances identical to a special FSW machine. This optimizes the jobshop machines and diversifies their technology offer to customers.

FSW Head