Friction spot welding

Recently, an innovative spot weld technique has appeared on the market, more specific friction spot welding (i.e. refill friction stir spot welding), where the connection is made through frictional heat. This welding technology is particularly suitable for welding aluminium, and provides a solution to the difficulties that resistance spot welding is facing for welding these materials, such as the electrode wear and tool life. Friction spot welding also has a remarkably greater employability, such as the welding of advanced higher-strength aluminium alloys, which are not weldable with conventional welding techniques. It is also possible to weld dissimilar materials such as aluminium-steel, coated aluminium alloys or materials with highly uneven thickness.

Working principle

In friction spot welding, a pin and sleeve are rotated. The sleeve plasticises the sheet material, which is accumulated inside the sleeve. When reaching a sufficient penetration depth, the rotating sleeve is pulled out again and the pin pushes the plastic material back into the weld crater to refill it and to create the connection.

Advantages of the process

highly suitable for welding aluminium,
offers a solution to the problems of resistance spot welding of aluminium alloys,
welding of advanced higher-strength aluminum alloys, which are not weldable with conventional welding techniques,
welding of dissimilar materials such as aluminium-steel, aluminium alloys or coated materials with uneven thickness,
short welding time,
ecological process: no filler materials or protective gases are used, no welding fumes, IR, UV or electromagnetic radiation during the process.

Feasibility study

BWI can assess the feasibility of this process for your materials or applications. We can also carry out welding trials with subsequent full weld characterisation. For further questions, please contact Koen Faes.