Research Projects

Friction Stir Welding

Friction stir welding (FSW) is a solid state joining process and has high productivity and excellent reproducibility. It is ideal for joining materials that are difficult to weld by conventional fusion welding techniques due to various solidification problems and harmful intermetallics formation, such as aluminium, magnesium alloys, metal matrix composites and dissimilar metals. SIMTech is the first institution who has established the welding capability of FSW in Singapore.

Specifications & Features

The friction stir welding equipment in SIMTech is a robotic friction stir welding machine with 6-axis range of motion and is capable of welding up to 25-mm Aluminium alloys type 6xxx. It has a 2.5-meter diameter working envelope with a maximum downward force of 12 kN and a maximum rotation speed of 3000 rpm. 



The key advantages of this technology include:

  • No gas porosity
  • No solidification cracking
  • No loss of alloying elements
  • Fine microstructure
  • Improved strength & fatigue properties
  • Low distortion of workpiece
  • Welding thick plates through one single pass
  • No shielding gas (Argon or Helium)
  • No consumable (filler & electrode)
  • No toxic fumes, spatter or radiation


SIMTech has strong expertise in FSW of Aluminium and Magnesium alloys, as well as Aluminium-based metal matrix composites and dissimilar metals. In addition, SIMTech is also actively involving in exploring new micro-FSW techniques to expand the possible application fields of this technology.



Contact PersonBi Guijun(

FSW can be applied to various types of joints like butt joints, lap joints, tee joints and fillet joints in aerospace, automotive, oil & gas, marine, precision engineering, parts repair and remanufacturing industries.


J. F. Guo, B. Y. Lee, Z. Du, G. Bi, M. J. Tan, J. Wei: Effect of nano-particle addition on grain structure evolution of friction stir-processed Al 6061 during postweld annealing, JOM, 2016, Vol. 68 (8), 2268-2273

J. F. Guo, H. C. Chen, C. N. Sun, G. Bi, Z. Sun, J. Wei: Friction stir welding of dissimilar materials between AA6061 and AA7075 Al alloys effects of process parameters, Materials & Design, 2014, Vol. 56, 185-192

J. F. Guo, J. Liu, G. Bi, M. J. Tan, J. Wei: Effects of nano-Al2O3 particle addition on grain structure evolution and mechanical behaviour of friction-stir-processed Al, Materials Science and Engineering: A, 2014, Vol. 602, 143-149